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Venous leg ulcers managed using polyurethane foam with a micropore dressing: two case reports

Nair HKR

J Wound Care, 2018 Sep 01;27(Sup9a):S37-S40.
PMID: 30207848 DOI: 10.12968/jowc.2018.27.Sup9a.S37

BACKGROUND: Cases of venous leg ulcers (VLU) are expected to rise due to the rapidly ageing population in Malaysia. Central to the management of these wounds is compression therapy together with an appropriate wound dressing. Pain and discomfort during dressing changes are common in these patients. Polyurethane foam dressings with SMARTPORE technology (micropore dressing; Mundipharma) facilitate vertical absorption of exudate to reduce risks of wound and periwound area maceration. They support easy dressing removal with less pain and trauma to the wound bed. Thus, the micropore dressing was chosen as a viable treatment option in these cases.
CASES: Case 1, a 74-year-old diabetic female was treated for bilateral VLUs with micropore dressing for several months, which she noted to be painless and convenient. Case 2, a 49-year-old housewife with a solitary VLU was treated with micropore dressing, leading to good treatment results and high satisfaction.
CONCLUSION: VLUs managed by the micropore dressing resulted in reduced pain and ease of use during dressing changes, as well as noticeable reduction in wound and periwound area maceration. The use of this type of dressing in these cases shows encouraging results and provides a desirable management option. More robust clinical studies are necessary to establish this.

Matched MeSH terms: Polyurethanes*
Ultrasonic assisted ultrafiltration process for emulsification of oil field produced water treatment

Agi A, Junin R, Alqatta AYM, Gbadamosi A, Yahya A, Abbas A

Ultrason Sonochem, 2019 Mar;51:214-222.
PMID: 30401623 DOI: 10.1016/j.ultsonch.2018.10.023

Ultrafiltration has been proven to be very effective in the treatment of oil-in-water emulsions, since no chemical additives are required. However, ultrafiltration has its limitations, the main limits are concentration polarization resulting to permeate flux decline with time. Adsorption, accumulation of oil and particles on the membrane surface which causes fouling of the membrane. Studies have shown that the ultrasonic is effective in cleaning of fouled membrane and enhancing membrane filtration performance. But the effectiveness also, depends on the selection of appropriate membrane material, membrane geometry, ultrasonic module design, operational and processing condition. In this study, a hollow and flat-sheet polyurethane (PU) membranes synthesized with different additives and solvent were used and their performance evaluated with oil-in-water emulsion. The steady-state permeate flux and the rejection of oil in percentage (%) at two different modes were determined. A dry/wet spinning technique was used to fabricate the flat-sheet and hollow fibre membrane (HFMs) using Polyethersulfone (PES) polymer base, Polyvinylpyrrolidone (PVP) additive and N, N-Dimethylacetamide (DMAc) solvent. Ultrasonic assisted cross-flow ultrafiltration module was built to avoid loss of ultrasonic to the surrounding. The polyurethane (PU) was synthesized by polymerization and sulphonation to have an anionic group (-OH; -COOH; and -SO3H) on the membrane surface. Changes in morphological properties of the membrane had a significant effect on the permeate flow rate and oil removal. Generation of cavitation and Brownian motion by the ultrasonic were the dominant mechanisms responsible for ultrafiltration by cracking the cake layers and reducing concentration polarization at the membrane surface. The percentage of oil after ultrafiltration process with ultrasonic is about 90% compared to 49% without ultrasonic. Ultrasonic is effective in enhancing the membrane permeate flux and controlling membrane fouling.

Matched MeSH terms: Polyurethanes
Fulltext UV-curable palm oil based-urethane acrylate/clay nanocomposites

Salih, A.M., Wan Md. Zin Wan Yunus, Khairul Zaman Mohd Dahlan, Mohd Hilmi Mahmood, Mansor Ahmad

Pertanika Journal of Science & Technology, 2012;20(2):435-444.
MyJurnal

Synthesis of palm oil based-urethane acrylate (POBUA) resins was carried out by acrylation of epoxidizedpalm oil (EPOP) using acrylic acid in the presence of a catalyst and followed by isocyanation to obtainthe POBUA. Using the monomer as a diluent in the formulation, 4% of photoinitiator and incorporationof organoclay (1-5% wt), nanocomposites were obtained upon UV irradiation. The X-ray DiffractoryXRD study revealed that the nanocomposites obtained were of the exfoliation type. The presence ofthe clay improved the hardness and did not affect the thermal stability. Similarly, it increased the glasstransition temperature Tg but reduced the modulus as the clay content was increased. The improvementof the tensile strength was only obtained when the clay concentration was 5 phr.

Matched MeSH terms: Polyurethanes
Fulltext UV-Curable Urethane Acrylate Resin from Palm Fatty Acid Distillate

Teo KT, Hassan A, Gan SN

Polymers (Basel), 2018 Dec 11;10(12).
PMID: 30961299 DOI: 10.3390/polym10121374

Palm fatty acid distillate (PFAD), is a by-product of the crude palm oil refining process. It comprises mainly of free fatty acids-around 45% palmitic and 33% oleic acids-as the major components. Ultra-violet (UV) curable urethane acrylate (UA) oligomers could be synthesized from PFAD, by the following procedure. A hydroxyl terminated macromer was first prepared by reacting PFAD with a mixture of isophthalic acid, phthalic anhydride, neopentagylcol (NPG), and pentaerythritol. The macromer was then reacted with 2-hydroxylethylacrylate (2HEA) and toluene diisocynate (TDI) to generate a resin, containing acrylate side chains for UV curable application. A series of UA resins were prepared by using 15, 25, 45, 55, and 70% of PFAD, respectively. The UA resin has Mw in the range of 3,200 to 27,000. They could be cured by UV irradiation at an intensity of 225 mW/cm². Glass transition temperature (Tg) of the cured film was measured by differential scanning calorimeter (DSC), and hardness of the film was determined by a pendulum hardness tester, according to American Society for Testing and Materials (ASTM)4366. The resins were used in a wood-coating application. All of the cured films showed good adhesion, hardness, and chemical resistance except for the one using the 70% PFAD, which did not cure properly.

Matched MeSH terms: Polyurethanes
Fulltext The effect of bur preparation on the surface roughness and reline bond strength of urethane dimethacrylate denture base resin

Baig MR, Ariff FT, Yunus N

Indian J Dent Res, 2011 Mar-Apr;22(2):210-2.
PMID: 21891887 DOI: 10.4103/0970-9290.84288

BACKGROUND: The clinical success of relining depends on the ability of reline resin to bond to denture base. Surface preparations may influence reline bond strength of urethane-based dimethacrylate denture base resin.
AIM: To investigate the effect of bur preparation on the surface roughness (R a ) of eclipse denture base resin and its shear bond strength (SBS) to an intra-oral self-curing reline material. The mode of reline bonding failure was also examined.
MATERIALS AND METHODS: Twenty-four cylindrical Eclipse™ specimens were prepared and separated into three groups of eight specimens each. Two groups were subjected to mechanical preparation using standard and fine tungsten carbide (TC) burs and the third group (control) was left unprepared. The R a of all specimens was measured using a contact stylus profilometer. Subsequently, relining was done on the prepared surface and SBS testing was carried out a day later using a universal testing machine.
RESULTS: One-way ANOVA revealed significant differences (P<0.05) in R a and SBS values for all the groups. Post-hoc Tukey's HSD test showed significant differences (P<0.05) between all the groups in the R a values. For SBS also there were significant differences (P<0.05), except between standard bur and control.
CONCLUSIONS: 1) There was a statistically significant difference in the R a of Eclipse™ specimens prepared using different carbide burs (P<0.05). 2) There was a statistically significant difference in the relined SBS (P<0.05) when prepared using different burs, but the difference between the standard bur and the control group was not statistically significant.

Matched MeSH terms: Polyurethanes/chemistry*
Fulltext Synthesis, Characterization and the Solvent Effects on Interfacial Phenomena of Jatropha Curcas Oil Based Non-Isocyanate Polyurethane

Haniffa MACM, Ching YC, Chuah CH, Kuan YC, Liu DS, Liou NS

Polymers (Basel), 2017 May 01;9(5).
PMID: 30970841 DOI: 10.3390/polym9050162

Non-isocyanate polyurethane (NIPU) was prepared from Jatropha curcas oil (JCO) and its alkyd resin via curing with different diamines. The isocyanate-free approach is a green chemistry route, wherein carbon dioxide conversion plays a major role in NIPU preparation. Catalytic carbon dioxide fixation can be achieved through carbonation of epoxidized derivatives of JCO. In this study, 1,3-diaminopropane (DM) and isophorone diamine (IPDA) were used as curing agents separately. Cyclic carbonate conversion was catalyzed by tetrabutylammonium bromide. After epoxy conversion, carbonated JCO (CJCO) and carbonated alkyd resin (CC-AR) with carbonate contents of 24.9 and 20.2 wt %, respectively, were obtained. The molecular weight of CJCO and CC-AR were determined by gel permeation chromatography. JCO carbonates were cured with different amine contents. CJCO was blended with different weight ratios of CC-AR to improve its characteristics. The cured NIPU film was characterized by spectroscopic techniques, differential scanning calorimetry, and a universal testing machine. Field emission scanning electron microscopy was used to analyze the morphology of the NIPU film before and after solvent treatment. The solvent effects on the NIPU film interfacial surface were investigated with water, 30% ethanol, methyl ethyl ketone, 10% HCl, 10% NaCl, and 5% NaOH. NIPU based on CCJO and CC-AR (ratio of 1:3) with IPDA crosslink exhibits high glass transition temperature (44 °C), better solvent and chemical resistance, and Young's modulus (680 MPa) compared with the blend crosslinked with DM. Thus, this study showed that the presence of CC-AR in CJCO-based NIPU can improve the thermomechanical and chemical resistance performance of the NIPU film via a green technology approach.

Matched MeSH terms: Polyurethanes
Fulltext Synthesis of UV-curable hyperbranched urethane acrylate from palm oil oleic acid

Mek Zah Salleh, Khairiah Badri, Sahrim Ahmad, Mohd Hilmi Mahmood

Journal of Nuclear and Related Technologies, 2010;2010(2):38-48.
MyJurnal

UV-curable hyperbranched urethane acrylate (HBPUA) from oleic acid of palm oil has been synthesized through a medium aided by p-toluene sulfonic acid as a catalyst. This mixture was then used as the core (HBP) and reacted with palm oil oleic acid to form the hyperbranched polyol (HBP-1). HBPUA was prepared by reacting HBP-1 resin with diisocyanate and hydroxyl-containing acrylate monomer with the presence of 0.1-2 wt% dibutyltin dilaurate as a catalyst. The reaction was confirmed by several analytical data i.e. hydroxyl value (OHV), Fourier Transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy analyses. The HBPUA was easily curable when subjected to ultraviolet (UV) radiation.

Matched MeSH terms: Polyurethanes
Synthesis and characterisation of composite sulphonated polyurethane/polyethersulphone membrane for blood purification application

Mansur S, Othman MHD, Ismail AF, Kadir SHSA, Goh PS, Hasbullah H, et al.

Mater Sci Eng C Mater Biol Appl, 2019 Jun;99:491-504.
PMID: 30889724 DOI: 10.1016/j.msec.2019.01.092

Polyurethane (PU) with three different functional groups: carboxyl, hydroxyl and sulphonyl group on its molecular structure were synthesised in this work. The synthesised material suppresses blood clotting and exhibits anticoagulant characteristics due to the presence of the important anionic groups. The synthesised PU was blended with polyethersulphone (PES) and fabricated into flat-sheet membrane to study the physico-chemical and biocompatibility properties of the PES membrane for blood purification application. PES-PU flat-sheet membranes were fabricated via the dry-wet phase separation technique. Different loading of PU (0, 1, 2, 3, 4, and 5%) blended with PES was studied and compared. Based on the in-vitro biocompatibility analysis of the membrane, it can be suggested that the membrane incorporated with PU has better anticoagulant properties compared to the pristine PES membrane. PU incorporation prolonged the clotting time, decreased the formation of thrombin, decreased soluble complement component 3a (C3a) generation and suppressed platelet adhesion and aggregation. The anionic groups on the membrane surface might bind to coagulation factors (antithrombin) and the calcium ions, Ca2+ and thus improve anticoagulant ability. Based on both physico-chemical and in-vitro studied, 4% loading of PU is the optimum loading for incorporation with PES membrane. These results suggested that the blended PES-PU membranes with good haemocompatibility allowed practical application in the field of blood purification.

Matched MeSH terms: Polyurethanes
Fulltext Surface, thermal and hemocompatible properties of novel single stage electrospun nanocomposites comprising polyurethane blended with bio oilTM

Ayyar M, Mani MP, Jaganathan SK, Rathinasamy R, Khudzari AZ, Krishnasamy NP

An Acad Bras Cienc, 2017;89(3 Suppl):2411-2422.
PMID: 29091109 DOI: 10.1590/0001-3765201720170230

In this work, the physicochemical and blood compatibility properties of prepared PU/Bio oil nanocomposites were investigated. Scanning electron microscope (SEM) studies revealed the reduction of mean fiber diameter (709 ± 211 nm) compared to the pristine PU (969 nm ± 217 nm). Fourier transform infrared spectroscopy (FTIR) analysis exposed the characteristic peaks of pristine PU. Composite peak intensities were decreased insinuating the interaction of the bio oilTM with the PU. Contact angle analysis portrayed the hydrophobic nature of the fabricated patch compared to pristine PU. Thermal gravimetric analysis (TGA) depicted the better thermal stability of the novel nanocomposite patch and its different thermal behavior in contrast with the pristine PU. Atomic force microscopy (AFM) analysis revealed the increase in the surface roughness of the composite patch. Activated partial thromboplastin time (APTT) and prothrombin time (PT) signified the novel nanocomposite patch ability in reducing the thrombogenicity and promoting the anticoagulant nature. Finally the hemolytic percentage of the fabricated composite was in the acceptable range revealing its safety and compatibility with the red blood cells. To reinstate, the fabricated patch renders promising physicochemical and blood compatible nature making it a new putative candidate for wound healing application.

Matched MeSH terms: Polyurethanes/chemistry*
Structure-property studies of thermoplastic and thermosetting polyurethanes using palm and soya oils-based polyols

Mohammed IA, Al-Mulla EA, Kadar NK, Ibrahim M

J Oleo Sci, 2013;62(12):1059-72.
PMID: 24292358

Palm and soya oils were converted to monoglycerides via transesterification of triglycerides with glycerol by one step process to produce renewable polyols. Thermoplastic polyurethanes (TPPUs) were prepared from the reaction of the monoglycerides which act as polyol with 4,4'-methylenediphenyldiisocyanate (MDI) whereas, thermosetting polyurethanes (TSPUs) were prepared from the reaction of glycerol, MDI and monoglycerides in one pot. Characterization of the polyurethanes was carried out by FT-IR, (1)H NMR, and iodine value and sol-gel fraction. The TSPUs showed good thermal properties compared to TPPUs as well as TSPUs exhibits good properties in pencil hardness and adhesion, however poorer in flexural and impact strength compared to TPPUs. The higher percentage of cross linked fraction, the higher degree of cross linking occurred, which is due to the higher number of double bond presents in the TSPUs. These were reflected in iodine value test as the highest iodine value of the soya-based thermosetting polyurethanes confirmed the highest degree of cross linking. Polyurethanes based on soya oil showed better properties compared to palm oil. This study is a breakthrough development of polyurethane resins using palm and soya oils as one of the raw materials.

Matched MeSH terms: Polyurethanes/chemical synthesis*; Polyurethanes/chemistry
Some mechanical properties of a highly cross-linked, microwave-polymerized, injection-molded denture base polymer

Memon MS, Yunus N, Razak AA

Int J Prosthodont, 2001 May-Jun;14(3):214-8.
PMID: 11484567

PURPOSE: The impact strength and the flexural properties of denture base materials are of importance in predicting their clinical performance upon sudden loading. This study compares the impact and transverse strengths and the flexural modulus of three denture base polymers.
MATERIALS AND METHODS: The investigation included a relatively new microwave-polymerized polyurethane-based denture material processed by an injection-molding technique, a conventional microwave-polymerized denture material, and a heat-polymerized compression-molded poly(methyl methacrylate) (PMMA) denture material. Impact strength was determined using a Charpy-type impact tester. The transverse strength and the flexural modulus were assessed with a three-point bending test. The results were subjected to statistical analysis using a one-way analysis of variance and the Scheffé test for comparison.
RESULTS: The impact strength of the microwave-polymerized injection-molded polymer was 6.3 kl/m2, while its flexural strength was 66.2 MPa. These values were lower than those shown by the two compression-molded PMMA-based polymers. The differences were statistically significant. The flexural modulus of the new denture material was 2,832 MPa, which was higher than the conventional heat-polymerized polymer but was comparable to the other microwave-polymerized PMMA-based polymer. The difference in the flexural modulus was statistically significant.
CONCLUSION: In terms of the impact and flexural strengths, the new microwave-polymerized, injection-molded, polyurethane-based polymer offered no advantage over the existing heat- and microwave-polymerized PMMA-based denture base polymers. However, it has a rigidity comparable to that of the microwave-polymerized PMMA polymer.

Matched MeSH terms: Polyurethanes/radiation effects; Polyurethanes/chemistry
Simultaneous 4-chlorophenol and nitrogen removal in moving bed sequencing batch reactors packed with polyurethane foam cubes of various sizes

Lim JW, Lim PE, Seng CE, Adnan R

Bioresour Technol, 2013 Feb;129:485-94.
PMID: 23266850 DOI: 10.1016/j.biortech.2012.11.111

Moving bed sequencing batch reactors (MBSBRs) packed with 8% (v/v) of 8-, 27- and 64-mL polyurethane (PU) foam cubes, respectively, were investigated for simultaneous 4-chlorophenol (4-CP) and nitrogen removal at increasing 4-CP concentration. When the 4-CP concentration exceeded 300 mg L(-1), the MBSBR with 27-mL foam cubes was observed to outperform the other MBSBRs in removing 4-CP and nitrogen. The reasons were: (1) there were more biomass in inner layer of the 27-mL cubes, compared to that of the 8-mL cubes, which was more shielded from the inhibitory effect of 4-CP and (2) the 27-mL cubes were more mobile than the 64-mL cubes. Although increasing 4-CP concentration to 600 mg L(-1) resulted in incomplete removal of 4-CP in the MBSBRs, results of the batch reactor with 27-mL foam cubes showed that complete 4-CP removal within the REACT period could be achieved by increasing the packing volume to 20%.

Matched MeSH terms: Polyurethanes/chemistry*
Rigid/flexible polyurethane foam composite boards with addition of functional fillers: acoustics evaluations

Huang C, Lou C, Chuang Y, Lin J, Liu C, Yu Z

Sains Malaysiana, 2015;44:1757-1763.

Following rapid technological and industrial development, factories have been equipped with a great deal of machines.
The blend of industrial and residential areas in turn resulted in many environmental problems. In particular, machine
operation causes noise pollution that easily causes physiological and psychological discomfort for the human body thus
makes noise abatement a crucial and urgent issue. In this study, vermiculite functional fillers were added to polyurethane
(PU) foam mixtures in order to form sound absorbent PU foams. The correlations between the contents of functional fillers
and the sound absorption of flexible and rigid PU foams were then examined. The optimal PU foams were combined with
PET/carbon fiber matrices in order to yield the electromagnetic shielding effectiveness. The sound absorption, noise
reduction coefficient (NRC), electromagnetic shielding effectiveness and resilience rate of the composite boards were
finally evaluated. The test results indicated that rigid PU foam composites can reach a sound absorption coefficient of
0.8 while the flexible PU foam composites have higher mechanical properties.

Matched MeSH terms: Polyurethanes
Recent advances in tissue engineering scaffolds based on polyurethane and modified polyurethane

Naureen B, Haseeb ASMA, Basirun WJ, Muhamad F

Mater Sci Eng C Mater Biol Appl, 2021 Jan;118:111228.
PMID: 33254956 DOI: 10.1016/j.msec.2020.111228

Organ repair, regeneration, and transplantation are constantly in demand due to various acute, chronic, congenital, and infectious diseases. Apart from traditional remedies, tissue engineering (TE) is among the most effective methods for the repair of damaged tissues via merging the cells, growth factors, and scaffolds. With regards to TE scaffold fabrication technology, polyurethane (PU), a high-performance medical grade synthetic polymer and bioactive material has gained significant attention. PU possesses exclusive biocompatibility, biodegradability, and modifiable chemical, mechanical and thermal properties, owing to its unique structure-properties relationship. During the past few decades, PU TE scaffold bioactive properties have been incorporated or enhanced with biodegradable, electroactive, surface-functionalised, ayurvedic products, ceramics, glass, growth factors, metals, and natural polymers, resulting in the formation of modified polyurethanes (MPUs). This review focuses on the recent advances of PU/MPU scaffolds, especially on the biomedical applications in soft and hard tissue engineering and regenerative medicine. The scientific issues with regards to the PU/MPU scaffolds, such as biodegradation, electroactivity, surface functionalisation, and incorporation of active moieties are also highlighted along with some suggestions for future work.

Matched MeSH terms: Polyurethanes*
Production of uv-curable palm oil resins/oligomers using laboratory scale and pilot scale systems

Rida Tajau, Mohd hilmi Mahmood, Mek Zah Salleh, Khairul Zaman Mohd dahlan, Rosley Che ismail, Sharilla Muhammad Faisal, et al.

Sains Malaysiana, 2013;42:459-467.

In recent years, there are growing trends in using palm oil as raw materials in radiation curable resins production. In this study, the acrylated palm oil resins i.e. the EPOLA (epoxidized palm oil acrylate) and the POBUA (palm oil based urethane acrylate) were synthesized using two different systems, i.e. the 25 liter pilot scale reactor synthesis system and the 2 liter (L) laboratory scale reactor synthesis system through chemical processes known as acrylation and isocyanation. In this
paper, the property of the acrylated resins which were produced by these two systems were evaluated and compared between each other. Their properties were characterized using the Fourier transform infrared (FTIR) spectrophotometer for functional group identification; the gel permeation chromatography (GPC) for molecular weight (Mw) determination, the Brookfield viscometer for viscosity measurements, the acid values (AV) and the oxirane oxygen contents (OOC) analysis. As a result, the production process for both the 2 L and 25 L reactor system were found to be time consuming and the main advantages for the 25 L reactor was its higher productivity as compared with the 2 L reactor system with the same synthesis process parameters i.e. the temperatures and the experimental methods. Besides that, the 25 L reactor synthesis
process was found to be safe, easy to control and served unpolluted process to the environments. The final products, the acrylated palm oil resins were formulated into ultraviolet (UV) curable compounds before subjecting them under UVirradiation. As a result, the UV-curable palm oil resins showed potential uses as pressure sensitive adhesives, printing inks including overprint varnishes (OPV) and coatings.

Matched MeSH terms: Polyurethanes
Fulltext Production of Biodegradable Palm Oil-Based Polyurethane as Potential Biomaterial for Biomedical Applications

Yeoh FH, Lee CS, Kang YB, Wong SF, Cheng SF, Ng WS

Polymers (Basel), 2020 Aug 17;12(8).
PMID: 32824514 DOI: 10.3390/polym12081842

Being biodegradable and biocompatible are crucial characteristics for biomaterial used for medical and biomedical applications. Vegetable oil-based polyols are known to contribute both the biodegradability and biocompatibility of polyurethanes; however, petrochemical-based polyols were often incorporated to improve the thermal and mechanical properties of polyurethane. In this work, palm oil-based polyester polyol (PPP) derived from epoxidized palm olein and glutaric acid was reacted with isophorone diisocyanate to produce an aliphatic polyurethane, without the incorporation of any commercial petrochemical-based polyol. The effects of water content and isocyanate index were investigated. The polyurethanes produced consisted of > 90% porosity with interconnected micropores and macropores (37-1700 µm) and PU 1.0 possessed tensile strength and compression stress of 111 kPa and 64 kPa. The polyurethanes with comparable thermal stability, yet susceptible to enzymatic degradation with 7-59% of mass loss after 4 weeks of treatment. The polyurethanes demonstrated superior water uptake (up to 450%) and did not induce significant changes in pH of the medium. The chemical changes of the polyurethanes after enzymatic degradation were evaluated by FTIR and TGA analyses. The polyurethanes showed cell viability of 53.43% and 80.37% after 1 and 10 day(s) of cytotoxicity test; and cell adhesion and proliferation in cell adhesion test. The polyurethanes produced demonstrated its potential as biomaterial for soft tissue engineering applications.

Matched MeSH terms: Polyurethanes
Fulltext Polyurethane Elastomer Layered Nanocomposite Material for Sports Grounds and the Preparation Method Thereof

Ren C, Su Z, Su Y, Wang L

Biomed Res Int, 2022;2022:5152911.
PMID: 36093408 DOI: 10.1155/2022/5152911

Polyurethane, as a rubber material, can relieve the load on the ground and provide seismic design for the venue, which is of great significance for sports venues. In order to improve the seismic resistance and abrasion resistance of materials for sports fields and reduce accidents in sports, this article has carried out research on the polyurethane elastomer layered nanocomposites for sports fields and their preparation. Today's world is a challenging era of science and technology. The fields of biotechnology, information, medicine, energy, environment, and national defense and security are closely related to the development of high tech, and the requirements for materials are becoming increasingly diversified. Polymer nanocomposite coating has the dual characteristics of organic and inorganic components. It not only retains the advantages of a polymer but also endows it with versatility. It meets the current application needs. It is a hot spot in today's research. Among them, there are two major problems in the composite process of nanomaterials and polymers: dispersion and compatibility. How to improve the dispersion of nanoparticles and enhance the compatibility between nanoparticles and polymers is an urgent problem to be solved. In the method part, this article introduces a small amount of polyurethane and polyurethane elastomers formed after polyurethane modification and introduces layered compounds and nanocomposites and introduces several models involved in nanomaterials in terms of algorithms. In the analysis part, this paper conducts a comprehensive analysis of the hard segment mass fraction, mechanical properties, thermal decomposition behavior, degradation mechanism, and dynamic mechanical properties. With the increase of GO content, the tensile strength increases significantly and the elongation at break becomes smaller and smaller. When the GO content increases from 0% to 2%, the tensile properties of the WPU film increase from 2.6 MPa to 7.9 MPa and the fracture of the elongation decreased from 201.7% to 62.8%. This shows that the increase in GO content will make the composite material harder and brittle. It can be seen from the experimental results that the preparation of the polyurethane elastomer layered nanocomposite material designed in this paper has a good application effect on sports venues.

Matched MeSH terms: Polyurethanes
Fulltext Performance Analysis of Jatropha Oil-Based Polyurethane Acrylate Gel Polymer Electrolyte for Dye-Sensitized Solar Cells

Rayung M, Aung MM, Su'ait MS, Chuah Abdullah L, Ahmad A, Lim HN

ACS Omega, 2020 Jun 23;5(24):14267-14274.
PMID: 32596563 DOI: 10.1021/acsomega.9b04348

Biobased polymers are useful materials in substituting conventional petroleum-derived polymers because of their good properties, ready availability, and abundance in nature. This study reports a new jatropha oil-based gel polymer electrolyte (GPE) for use in dye-sensitized solar cells (DSSCs). The GPE was prepared by mixing jatropha oil-based polyurethane acrylate (PUA) with different concentrations of lithium iodide (LiI). The GPE was characterized by infrared spectroscopy, thermal analysis, lithium nuclear magnetic resonance analysis, electrochemical analysis, and photocurrent conversion efficiency. The highest room-temperature ionic conductivity of 1.88 × 10-4 S cm-1 was obtained at 20 wt % of LiI salt. Additionally, the temperature-dependent ionic conductivity of the GPE exhibited Arrhenius behavior with an activation energy of 0.42 eV and a pre-exponential factor of 1.56 × 103 S cm-1. The electrochemical stability study showed that the PUA GPE was stable up to 2.35 V. The thermal stability of the gel electrolyte showed an improvement after the addition of the salt, suggesting a strong intermolecular interaction between PUA and Li, which leads to polymer-salt complexation, as proven by Fourier transform infrared spectroscopy analysis. A DSSC has been assembled using the optimum ionic conductivity gel electrolyte which indicated 1.2% efficiency under 1 sun condition. Thus, the jatropha oil-based GPE demonstrated favorable properties that make it a promising alternative to petroleum-derived polymer electrolytes in DSSCs.

Matched MeSH terms: Polyurethanes
Optimization and development of Maghemite (γ-Fe2O3) filled poly-l-lactic acid (PLLA)/thermoplastic polyurethane (TPU) electrospun nanofibers using Taguchi orthogonal array for tissue engineering heart valve

Fallahiarezoudar E, Ahmadipourroudposht M, Idris A, Yusof NM

Mater Sci Eng C Mater Biol Appl, 2017 Jul 01;76:616-627.
PMID: 28482571 DOI: 10.1016/j.msec.2017.03.120

Tissue engineering (TE) is an advanced principle to develop a neotissue that can resemble the original tissue characteristics with the capacity to grow, to repair and to remodel in vivo. This research proposed the optimization and development of nanofiber based scaffold using the new mixture of maghemite (γ-Fe2O3) filled poly-l-lactic acid (PLLA)/thermoplastic polyurethane (TPU) for tissue engineering heart valve (TEHV). The chemical, structural, biological and mechanical properties of nanofiber based scaffold were characterized in terms of morphology, porosity, biocompatibility and mechanical behaviour. Two-level Taguchi experimental design (L8) was performed to optimize the electrospun mats in terms of elastic modulus using uniaxial tensile test where the studied parameters were flow rate, voltage, percentage of maghemite nanoparticles in the content, solution concentration and collector rotating speed. Each run was extended with an outer array to consider the noise factors. The signal-to-noise ratio analysis indicated the contribution percent as follow; Solution concentration>voltage>maghemite %>rotating speed>flow rate. The optimum elastic modulus founded to be 28.13±0.37MPa in such a way that the tensile strain was 31.72% which provided desirability for TEHV. An empirical model was extracted and verified using confirmation test. Furthermore, an ultrafine quality of electrospun nanofibers with 80.32% porosity was fabricated. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and cell attachment using human aortic smooth muscle cells exhibited desirable migration and proliferation over the electrospun mats. The interaction between blood content and the electrospun mats indicated a mutual adaption in terms of clotting time and hemolysis percent. Overall, the fabricated scaffold has the potential to provide the required properties of aortic heart valve.

Matched MeSH terms: Polyurethanes
Fulltext Optimisation of Epoxide Ring-Opening Reaction for the Synthesis of Bio-Polyol from Palm Oil Derivative Using Response Surface Methodology

Kamairudin N, Hoong SS, Abdullah LC, Ariffin H, Biak DRA

Molecules, 2021 Jan 27;26(3).
PMID: 33513686 DOI: 10.3390/molecules26030648

The development of bio-polyol from vegetable oil and its derivatives is gaining much interest from polyurethane industries and academia. In view of this, the availability of methyl oleate derived from palm oil, which is aimed at biodiesel production, provides an excellent feedstock to produce bio-polyol for polyurethane applications. In this recent study, response surface methodology (RSM) with a combination of central composite rotatable design (CCRD) was used to optimise the reaction parameters in order to obtain a maximised hydroxyl value (OHV). Three reaction parameters were selected, namely the mole ratio of epoxidised methyl oleate (EMO) to glycerol (1:5-1:10), the amount of catalyst loading (0.15-0.55%) and reaction temperature (90-150 °C) on a response variable as the hydroxyl value (OHV). The analysis of variance (ANOVA) indicated that the quadratic model was significant at 98% confidence level with (p-value > 0.0001) with an insignificant lack of fit and the regression coefficient (R2) was 0.9897. The optimum reaction conditions established by the predicted model were: 1:10 mole ratio of EMO to glycerol, 0.18% of catalyst and 120 °C reaction temperature, giving a hydroxyl value (OHV) of 306.190 mg KOH/g for the experimental value and 301.248 mg KOH/g for the predicted value. This result proves that the RSM model is capable of forecasting the relevant response. FTIR analysis was employed to monitor the changes of functional group for each synthesis and the confirmation of this finding was analysed by NMR analysis. The viscosity and average molecular weight (MW) were 513.48 mPa and 491 Da, respectively.

Matched MeSH terms: Polyurethanes/chemistry

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