Starch is a biodegradable polymer produced in abundance from many renewable resources. This study examined the influence of citric acid (0-40% w/wt%) ) and water (0-40% w/wt%) as secondary additive and glycerol as plasticizer on the mechanical properties of bio-plastic starch (BPS) from Malaysian sago. The CA content varies from 0 to 40 w/wt% while water was also varied from 0 to 40 w/wt%. FT-IR spectroscopy showed that acid citric improve the properties of BPS and water give negative effects to the carbon hydrogenbond. It is obvious that the addition of the CA at 30 wt/wt% improve the mechanical property of BPS to more than 40% compare to the addition of water.
A binary salt system utilizing lithium iodide (LiI) as the auxiliary component has been introduced to the N-phthaloylchitosan (PhCh) based gel polymer electrolyte consisting of ethylene carbonate (EC), dimethylformamide (DMF), tetrapropylammonium iodide (TPAI), and iodine (I2) in order to improve the performance of dye-sensitized solar cell (DSSC) with efficiency of 6.36%, photocurrent density, JSC of 17.29mAcm-2, open circuit voltage, VOC of 0.59V and fill factor, FF of 0.62. This efficiency value is an improvement from the 5.00% performance obtained by the DSSC consisting of only TPAI single salt system. The presence of the LiI in addition to the TPAI improves the charge injection rates and increases the iodide contribution to the total conductivity and both factors contribute to the increase in efficiency of the DSSC. The interaction behavior between polymer-plasticizer-salt was thoroughly investigated using EIS, FTIR spectroscopy and XRD.
Indoor air pollution with toxic volatile organic compounds (VOCs) and fine particulate matter (PM2.5) is a threat to human health, causing cancer, leukemia, fetal malformation, and abortion. Therefore, the development of technologies to mitigate indoor air pollution is important to avoid adverse effects. Adsorption and photocatalytic oxidation are the current approaches for the removal of VOCs and PM2.5 with high efficiency. In this review we focus on the recent development of indoor air pollution mitigation materials based on adsorption and photocatalytic decomposition. First, we review on the primary indoor air pollutants including formaldehyde, benzene compounds, PM2.5, flame retardants, and plasticizer: Next, the recent advances in the use of adsorption materials including traditional biochar and MOF (metal-organic frameworks) as the new emerging porous materials for VOCs absorption is reviewed. We review the mechanism for mitigation of VOCs using biochar (noncarbonized organic matter partition and adsorption) and MOF together with parameters that affect indoor air pollution removal efficiency based on current mitigation approaches including the mitigation of VOCs using photocatalytic oxidation. Finally, we bring forward perspectives and directions for the development of indoor air mitigation technologies.
The main goal of the present work was to develop a value-added product of biodegradable material for sustainable packaging. The use of agriculture waste-derived carboxymethyl cellulose (CMC) mainly is to reduce the cost involved in the development of the film, at present commercially available CMS is costly. The main focus of the research is to translate the agricultural waste-derived CMC to useful biodegradable polymer suitable for packaging material. During this process CMC was extracted from the agricultural waste mainly sugar cane bagasse and the blends were prepared using CMC (waste derived), gelatin, agar and varied concentrations of glycerol; 1.5% (sample A), 2% (sample B), and 2.5% (sample C) was added. Thus, the film derived from the sample C (gelatin + CMC + agar) with 2.0% glycerol as a plasticizer exhibited excellent properties than other samples A and B. The physiochemical properties of each developed biodegradable plastics (sample A, B, C) were characterized using Fourier Transform Infra-Red (FTIR) spectroscopy and Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA). The swelling test, solubility in different solvents, oil permeability coefficient, water permeability (WP), mechanical strength of the produced material was claimed to be a good material for packaging and meanwhile its biodegradability (soil burial method) indicated their environmental compatibility nature and commercial properties. The reflected work is a novel approach, and which is vital in the conversion of organic waste to value-added product development. There is also another way to utilize commercial CMC in preparation of polymeric blends for the packaging material, which can save considerable time involved in the recovery of CMC from sugarcane bagasse.
A flexible solid polymer electrolyte (SPE) system based on poly(ε-caprolactone) (PCL), a FDA approved non-toxic and biodegradable material in the effort to lower environmental impact was prepared. Ammonium thiocyanate (NH4SCN) and ethylene carbonate (EC) were incorporated as the source of charge carriers and plasticizing agent, respectively. When 50wt.% of ethylene carbonate (EC) was added to PCL-NH4SCN system, the conductivity increased by two orders from of 3.94×10(-7)Scm(-1) to 3.82×10(-5)Scm(-1). Molecular vibrational analysis via infrared spectroscopy had been carried out to study the interaction between EC, PCL and NH4SCN. The relative percentage of free ions, ion pairs and ion aggregates was calculated quantitatively by deconvoluting the SCN(-) stretching mode (2030-2090cm(-1)). This study provides fundamental insight on how EC influences the free ion dissociation rate and ion mobility. The findings are also in good agreement to conductivity, differential scanning calorimetry and X-ray diffraction results. High dielectric constant value (89.8) of EC had made it an effective ion dissociation agent to dissociate both ion pairs and ion aggregates, thus contributing to higher number density of free ions. The incorporation of EC had made the polymer chains more flexible in expanding amorphous domain. This will facilitate the coupling synergy between ionic motion and polymer segmental motion. Possible new pathway through EC-NH4(+) complex sites for ions to migrate with shorter distance has been anticipated. This implies an easier ion migration route from one complex site to another.
The capacity of microwave non-destructive testing (NDT) technique to characterize the matrix property of binary polymeric films for use as transdermal drug delivery system was investigated. Hydroxypropylmethylcellulose (HPMC) and polyethylene glycol (PEG) 3000 were the choice of polymeric matrix and plasticizer, respectively with loratadine as the model drug. Both blank and drug loaded HPMC-PEG 3000 films were prepared using the solvent-evaporation method. These films were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using the established methods of ultra-violet spectrophotometry, differential scanning calorimetry and Fourier transform infrared spectroscopy methods, as well as, novel microwave NDT technique. Blank films exhibited a greater propensity of polymer-polymer interaction at the O-H domain upon storage at a lower level of relative humidity, whereas drug loaded films exhibited a greater propensity of polymer-polymer, polymer-plasticizer and/or drug-polymer interaction via the O-H, C-H and/or aromatic C=C functional groups when they were stored at a lower or moderate level of relative humidity. The absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer, polymer-plasticizer, and/or drug-polymer interaction of the matrix. The measurements of microwave NDT test at 8 and 12 GHz were sensitive to the polar fraction of film involving functional group such as O-H moiety and the less polar environment of matrix consisting of functional groups such as C-H and aromatic C=C moieties. The state of interaction between polymer, plasticizer and/or drug of a binary polymeric film can be elucidated through its absorption and transmission profiles of microwave.
Fourier transform infrared (FT-IR) spectroscopic studies have been undertaken to investigate the interactions among components in a system of hexanoyl chitosan-lithium trifluoromethanesulfonate (LiCF(3)SO(3))-diethyl carbonate (DEC)/ethylene carbonate (EC). LiCF(3)SO(3) interacts with the hexanoyl chitosan to form a hexanoyl chitosan-salt complex that results in the shifting of the N(COR)(2), CONHR and OCOR bands to lower wavenumbers. Interactions between EC and DEC with LiCF(3)SO(3) has been noted and discussed. Evidence of interaction between EC and DEC has been obtained experimentally. Studies on polymer-plasticizer spectra suggested that there is no interaction between the polymer host and plasticizers. Competition between plasticizer and polymer on associating with Li(+) ions was observed from the spectral data for gel polymer electrolytes. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolytes.
Humans are exposed to endocrine disrupting compounds (EDCs) in tap water via drinking water. Currently, most of the analytical methods used to assess a long list of EDCs in drinking water have been made available only for a single group of EDCs and their metabolites, in contrast with other environmental matrices (e.g., surface water, sediments, and biota) for which more robust methods have been developed that allow detection of multiple groups. This study reveals an analytical method of one-step solid phase extraction, incorporated together with liquid chromatography-tandem mass spectrometry for the quantification of multiclass EDCs (i.e., pharmaceuticals, hormones, plasticizers, and pesticides) in drinking water. Fifteen multiclass EDCs significantly varied in amount between field samples (p
Starch blend films made from sago and mung bean were prepared by casting with glycerol as the plasticizer and subsequently exposed to ultraviolet (UV) irradiation for 2 h. The films were characterized by thickness, moisture sorption isotherms, X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. All films produced were colorless while incorporation of glycerol resulted in more flexible and manageable films. Moisture sorption isotherms for all films showed sigmoidal shape and the control films showed slightly higher curve than treated films. While for X-ray analysis, the control and treated films for all formulations showed similar pattern, however for treated films showed more crystalline character. UV radiation showed affect on X-ray diffraction and sorption isotherms; however the UV radiation did not affect the spectra pattern of FTIR.
Several methods of incorporating sago pith waste (SPW) into poly(vinyl alcohol) (PVA) had been conducted: (i) dry blending (PVA/SPW/G), (ii) blending of SPW and pre-plasticized PVA (pPVA/SPW/G) and (iii) blending of pre-plasticized of both PVA and SPW (pPVA/pSPW). The effect of the compounding method on the mechanical and water absorption properties were investigated. The addition of SPW into PVA greatly reduced the tensile strength and elongation at break. The tensile strength and elongation at break of PVA/SPW composites with identical geometry during compounding stage (powder/powder and pellet/pellet), which were PVA/SPW/G and pPVA/pSPW yielded the highest value. The percentage of water absorbed by PVA/SPW/G (without pre-plasticization) was the highest, followed by pPVA/pSPW and pPVA/SPW/G.
The cellulose microfibers (CMF) from water hyacinth (WH) fiber as a filler in sago starch (SS) biocomposites was investigated. The CMF was isolated by pulping, bleaching and acid hydrolysis methods. The addition of CMF in sago matrix was varied i.e. 0, 5, 10, 15 and 20 wt%. Biocomposites were made by using solution casting and glycerol as a plasticizer. The biocomposites were also determined by tensile test, FTIR, X-Ray, thermogravimetric, SEM, and soil burial tests. The results show that the SS15CMF sample has the highest tensile strength of 10.23 MPa than those other samples. Scanning Electron Microscope (SEM) images show that the strong interaction was formed between CMF WH and matrix. Fourier Transform Infra-red (FTIR) indicated that the functional group of biocomposites was a hydrophilic cluster. The addition of CMF WH in sago starch biocomposites lead to the moisture barrier, crystallinity, and thermal stability increased; it is due to the pure sago starch film was more rapidly degraded than its biocomposites.
Poly(lactic acid) (PLA) is known to be a useful material in substituting the conventional petroleum-based polymer used in packaging, due to its biodegradability and high mechanical strength. Despite the excellent properties of PLA, low flexibility has limited the application of this material. Thus, epoxidized palm olein (EPO) was incorporated into PLA at different loadings (1, 2, 3, 4 and 5 wt%) through the melt blending technique and the product was characterized. The addition of EPO resulted in a decrease in glass transition temperature and an increase of elongation-at-break, which indicates an increase in the PLA chain mobility. PLA/EPO blends also exhibited higher thermal stability than neat PLA. Further, the PLA/1 wt% EPO blend showed enhancement in the tensile, flexural and impact properties. This is due to improved interaction in the blend producing good compatible morphologies, which can be revealed by Scanning Electron Microscopy (SEM) analysis. Therefore, PLA can be efficiently plasticized by EPO and the feasibility of its use as flexible film for food packaging should be considered.
The potential of Averrhoa bilimbi pectin (ABP) as a source of biopolymer for edible film (EF) production was explored, and deep eutectic solvent (DES) (1% w/w) containing choline chloride-citric acid monohydrate at a molar ratio of 1:1 was used as the plasticizer. The EF-ABP3:1, which was produced from ABP with large branch size, showed a higher value of melting temperature (175.30 °C), tensile stress (7.32 MPa) and modulus (33.64 MPa). The EF-ABP3:1 also showed better barrier properties by obtaining the lowest water vapor transmission rates (1.10-1.18 mg/m2.s) and moisture absorption values (2.61-32.13%) depending on the relative humidity compared to other EF-ABPs (1.39-1.83 mg/m2.s and 3.48-51.50%, respectively) that have linear structure with smaller branch size. From these results, it was suggested that the galacturonic acid content, molecular weight, degree of esterification and pectin structure of ABP significantly influenced the properties of EFs. The interaction of highly branched pectin chains was stronger than the linear chains, thus reduced the effect of plasticizer and produced a mechanically stronger EF with better barrier properties. Hence, it was suggested that these EFs could be used as alternative degradable packaging/coating materials.
The objective of this study was to develop biodegradable active film to improve the shelf-life of minimally processed fresh-produce. Guar gum (GG) based films with improved properties were fabricated by employing tween-80 (0.88%) as emulsifier, nanoclay (13.9%) as reinforcement, beeswax (1.21%) for hydrophobicity, glycerol (3.07%) as plasticizer, and grape pomace extract (5%) as active ingredient (%w/w of GG). Active films had a tensile strength of 122 MPa and water vapor transmission rate of 69 gm-2d-1. Films demonstrated significant antimicrobial activity against Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Salmonella Typhimurium. The 2 kGy irradiated minimally processed pomegranate arils packed in film demonstrated a shelf-life of 12 days as compared to 4 days for unirradiated samples. The observed improvement in shelf-life was due to a radiation-induced release of antimicrobial volatiles from active films as confirmed by headspace analysis using GC-MS. Suitability of active films for food irradiation applications is thus demonstrated.
Coating has been widely used in pharmaceutical manufacture either as non-functional or a functional entity. The objectives of the present study were to investigate the effect of plasticizers such as PEG400, PEG1000 and triacetin on mechanical properties, glass transition temperature and water vapor transmission of free films prepared from HPMC and/or HPMC:PVA blends, to develop suitable coating system for tablets, and to determine the release profiles of the coated tablets. The tensile strength of plasticized HPMC films was generally lower than that of control HPMC film and could be attributed to increased crystallinity and segmental chain mobility of HPMC. This effect increased as the concentration of plasticizer increased. Generally the addition of both grades of polyethylene glycol (PEG400 & PEG1000) increased the moisture permeability of HPMC films but the films containing triacetin provided a more rigid barrier to moisture compared to unplasticized HPMC films. The dissolution profiles of paracetamol tablets coated with 7% w/v HPMC coating-solutions containing PEG400, PEG1000 and triacetin, and those containing PEG400 & PVA together showed that HPMC had weak water resistance. The presence of PEG400 and 1000 in HPMC films further weakened its resistance to solubility while the presence of triacetin caused a little increase in HPMC water resistance. From the results it was concluded that HPMC at 7%w/w concentration was suitable for film-coating intended for non-functional coating. Presence of the PEG 400, PEG1000 and triacetin as well as the presence of PVA and PEG400 together improved the coating properties of HPMC films and made it more suitable as a non-functional coating material.
In this study, sugar palm starch (SPS) films were developed using glycerol (G), sorbitol (S) or their combination (GS) as plasticizers at the ratio of 15, 30 and 45 (wt)% using casting technique. The addition of plasticizers to SPS film-forming solutions helped to overcome the brittle and fragile nature of unplasticized SPS films. Increased plasticizer concentration resulted to an increase in film thickness, moisture content and solubility. On the contrary, density and water absorption of plasticized films decreased with increasing plasticizer concentration. Raising the plasticizer content from 15 to 45 % showed less effect on the moisture content and water absorption of S-plasticized films. Films containing glycerol and glycerol-sorbitol plasticizer (G, and GS) demonstrated higher moisture content, solubility and water absorption capacity compared to S-plasticized films. The results obtained in this study showed that plasticizer type and concentration significantly improves film properties and enhances their suitability for food packaging applications.
A study on the quality of water abstracted for potable use was conducted in the Selangor River basin from November 2008 to July 2009. Seven sampling sites representing the intake points of water treatment plants in the basin were selected to determine the occurrence and level of 15 organochlorine pesticides (OCPs), six phthalate esters (PAEs) and bisphenol A (BPA). Results indicated OCPs were still detected regularly in 66.1 % of the samples with the Σ(15)OCPs ranging from 0.6-25.2 ng/L. The first data on PAEs contamination in the basin revealed Σ(6)PAEs concentrations were between 39.0 and 1,096.6 ng/L with a median concentration of 186.0 ng/L while BPA concentration ranged from <1.2 to 120.0 ng/L. Although di-n-butyl phthalate was detected in all the samples, concentrations of di-ethyl(hexyl)phthalate were higher. Sampling sites located downstream recorded the highest concentrations, together with samples collected during the dry season. Comparison of the detected contaminants with the Department of Environment Water Quality Index (DOE-WQI) showed some agreement between the concentration and the current classification of stream water. While the results suggest that the sites were only slightly polluted and suitable to be used as drinking water source, its presence is cause for concern especially to the fragile firefly "Pteroptyx tener" ecosystem located further downstream.
Linearity assessment as required in method validation has always been subject to different interpretations and definitions by various guidelines and protocols. However, there are very limited applicable implementation procedures that can be followed by a laboratory chemist in assessing linearity. Thus, this work proposes a simple method for linearity assessment in method validation by a regression analysis that covers experimental design, estimation of the parameters, outlier treatment, and evaluation of the assumptions according to the International Union of Pure and Applied Chemistry guidelines. The suitability of this procedure was demonstrated by its application to an in-house validation for the determination of plasticizers in plastic food packaging by GC.
Halloysite nanotubes (HNTs)-polyester nanocomposites with four different concentrations were produced using solution casting technique and the biodegradation effect of short-term seawater exposure (120 h) was studied. Monolithic polyester was observed to have the highest seawater absorption with 1.37%. At 0.3 wt % HNTs reinforcement, the seawater absorption dropped significantly to the lowest value of 0.77% due to increase of liquid diffusion path. For samples tested in dry conditions, the Tg, storage modulus, tensile properties and flexural properties were improved. The highest improvement of Tg was from 79.3 to 82.4 °C (increase 3.1 °C) in the case of 0.3 wt % HNTs. This can be associated with the exfoliated HNTs particles, which restrict the mobility of polymer chains and thus raised the Tg. After seawater exposure, the Tg, storage modulus, tensile properties and flexural properties of polyester and its nanocomposites were decreased. The Young's modulus of 0.3 wt % HNTs-polyester dropped 20% while monolithic polyester dropped up to 24% compared to their values in dry condition. Apart from that, 29% flexural modulus reduction was observed, which was 18% higher than monolithic polyester. In contrast, fracture toughness and surface roughness increased due to plasticization effect. The presence of various microbial communities caused gradual biodegradation on the microstructure of the polyester matrix as also evidently shown by SEM images.
A flow injection potentiometric method for the rapid determination of paraquat in herbicide formulations and biological samples is described. It is based on the utilization of a flow-through potentiometric detector containing polyvinyl chloride-immobilised octamethylcyclotetrasiloxane, a lipophilic plasticizer (tetra-n-undecyl 3,3',4,4'-benzophenone tetracarboxylate) and membrane additive potassium tetrakis(4-chlorophenyl)borate. The detector was minimally interfered by the presence of constituents such as Na(+), K(+), Ca(2+), Mg(2+), glucose, urea, lactic and citric acids at physiological levels, respectively. Good correlation between results of the proposed method and HPLC for the formulation samples was found, while results for the determination of paraquat in biological samples such as urine, vomitus and stomach washout was less satisfactory.