Graft copolymerization of acrylonitrile onto torch ginger cellulose was carried out in an aqueous medium with ceric ion
redox initiator. The optimum grafting parameters such as temperature, reaction time, ratio of monomer to cellulose addition
and ceric ammonium nitrate (CAN) concentration were determined and a maximum graft yield of 40% was recorded.
The graft copolymer was characterized and compared with untreated cellulose. A new absorption peak corresponding
to the nitrile group of acrylonitrile was recorded by FTIR at 2244 cm-1 on the grafted cellulose. The morphology studies
showed that the diameter and the surface roughness of grafted cellulose had increased as compared with the untreated
cellulose. On the contrary, the grafting had resulted in lowering the crystallinity of the cellulose from 63 to 53%. The
grafted cellulose produced a new derivative TG peak at 420°C and higher residual percentage than the untreated cellulose
Surface modification of rice husk (RH) with alkali pre-treatment (NaOH solution 5% w/v) was carried out at the initial state to investigate the effect of surface treatment of fibre on the surface interaction between fibre and rubber. Further modification of RH surfaces after alkali treatment was using Liquid Epoxidized Natural Rubber (LENR) coating at three concentrations, 5%, 10%, and 20% wt LENR solution in toluene. Interfacial morphology and chemical reactions between RH fibre and rubber were analyzed by FTIR and Scanning Electron Microscope (SEM). It was found that 10% wt LENR solution gave the optimum interaction between fibre and rubber. Matrix and composite blends derived from 60% natural rubber (NR), 40% high density polyethylene (HDPE) reinforced with RH fibre were prepared using an internal mixer (Brabender Plasticoder). Result showed that pre-treatment of RH treated with 5% NaOH followed by treatment with 10% LENR solution given the maximum interaction between fibre and matrix that gave rise to better mechanical properties of the composites.
The presence of pores plays an important role for many membrane processes especially in ultrafiltration and microfiltration. Epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) membranes filled with two types of silica fillers were prepared via simultaneous solvent exchange and evaporation of solvent technique. Two types of silica, i.e. microsilica (microcrystalline
silica powder) and nanosilica (generated from tetraethoxysilane (TEOS)) were used. The chemical composition, morphology and mechanical stability of the membranes were studied. Both types of silica showed good interaction with the membrane matrix. The formation of pores depended on the size of silica particles added. Microsilica produced large pores while insitu generated nanosilica produced nanosized pores. The mechanical properties of membrane improved with the addition
of silica. The tensile strength increased from 10.6 MPa to 17.8 MPa and 14.5 MPa for nanosilica and microsilica filled membrane while the tensile modulus increased from 1.6 MPa to 3.8 MPa and 3.4 MPa, respectively. Thus, both types of silica acted as a filler as well as pore forming agent for the ENR/PVC membrane.
Kesan penambahan pengisi sekam padi dan tanah liat ke dalam matriks getah asli getah asli cecair polietilena berketumpatan tinggi (NR/LNR/HDPE), NR/HDPE dan HDPE terhadap sifat mekanik dan morfologi adunan telah dikaji. Pemprosesan adunan dilakukan pada suhu 140°C dan kadar percampuran 50 r.p.m. selama 16 minit. Pra-pemanasan pengisi selama 4 minit pada suhu 80°C dilakukan sebelum pengadunan dengan matriks bagi meminimumkan kesan lembapan. Getah asli cecair digunakan sebagai agen pengserasi dalam adunan komposit. Pengisian sekam padi (SP) dan tanah liat (TL) dalam matrik HDPE, NR/HDPE serta NR/LNR/HDPE umumnya menurunkan nilai kekuatan tensil dan kekuatan hentaman tetapi meningkatkan nilai modulus. Kehomogenan adunan komposit berpengisi yang dikenal pasti melalui pemeriksaan morfologi menggunakan mikroskop imbasan elektron (SEM) menunjukkan masalah aglomerasi dan interaksi antara muka dalam komposit berlaku. Kelikatan leburan dan interaksi antara bahan menentukan arah pergerakan serta serakan pengisi dalam komposit. Daripada keputusan yang diperolehi dan merujuk kedua-dua sifat pengisi, SP adalah lebih serasi dengan NR disebabkan potensi interaksi antara kumpulan berfungsi permukaan pengisi selulosa (SP) seperti –OH dengan ikatan ganda dua NR berbanding TL. Ciri fizik permukaan TL yang kurang bersifat hidrofilik berbanding SP pula menyebabkan TL lebih cenderung berinteraksi dan tersebar dengan baik dalam HDPE.
Cellulose nanocrystals (CNC) from mengkuang leaves (Pandanus tectorius) were investigated as potential reinforcement
in poly(vinyl chloride) (PVC) matrix. The surface of CNC was modified with silane coupling agent to improve fillermatrix
adhesion. Solution casting method was used to prepare PVC nanocomposites with various amounts of modified
(SCNC) and unmodified (CNC) nanocrystals. Both SCNC and CNC were examined by Fourier transform infrared (FTIR)
spectroscopy and X-ray diffraction (XRD) which showed that surface chemical modification has occurred. An increase
in tensile strength was observed with the addition of SCNC compared to the CNC. However, the elongation at break of the
nanocomposites was found to decrease with the increase of both fillers loading. An increasing trend was observed in the
tensile modulus with the addition of CNC to the PVC matrix, but decreasing with the addition of SCNC. The morphology
of a fractured surface of nanocomposites showed silane modification reduced the number of voids in the structure of
PVC. The observation indicated the adhesion between the fiber and the matrix had improved upon surface modification
of the nanocrystals with silane.
The effects of HVA-2 on radiation-induced cross-linkings in 60/40 natural rubber/ linear low density polyethylene (NR/LLDPE) blends was studied. NR/LLDPE was irradiated by using a 3.0 MeV electron beam machine with doses ranging from 0 to 250 kGy. Results showed that under the irradiation employed, the blends NR/LLDPE were cross-linked by the electron beam irradiation. The presence of HVA-2 in the blends caused the optimum dose to decrease and the blends to exhibit higher tensile properties. Further, within the dose range studied, the degradation caused by electron beam irradiation was found to be minimal. The optimized processing conditions were 120oC, 50 rpm rotor speed and 13 min processing time. The gel content, tensile strength, elongation at break, hardness and impact test studies were used to follow the irradiation-induced cross-linkings in the blend. For blends of 60/40 NR/LLDPE with 2.0 phr HVA-2, the optimum tensile strength and dose, were 19 MPa and 100 kGy, respectively. Blends of 60/40 NR/LLDPE without HVA-2, the optimum tensile strength and dose were 17.2 MPa and 200 kGy, respectively.
Blends of fibre-reinforced rubber based on natural rubber-thermoplastic (NR/LLDPE) reinforced by aramid fibre have been done using melt blending process. Two different processing methods were used; internal mixer and extrusion compounding in twin screw extruder. Twaron loading in the system was varied from 0 to 30%. It was found that increasing the amount of aramid fibre led to an increase in the tensile strength, tensile modulus and hardness of the composites while the strain decreased rapidly. The results showed that the optimum composition of filler loading in NR/LLDPE blend is 20%. The ,echanical behaviour was caused by the strong Twaron-matrices interaction in the composites and effective stress concentrating function of Twaron. Composites prepared using the twin-screw extruder have a higher tensile strength and tensile using the twin-screw extruder have a higher tensile stength and tensile modulus but lower impact strength compared to those prepared using internal mixer. Study of the fracture surface by scanning electron microscopy showed that the composite prepared using the internal mixer produced random fiber orientation while the twin-screw extruder produced the fibers aligned to the longitudinal direction. The results indicate that the mechanical properties of the composite were significantly influenced by the processing technique.
Penyediaan komposit getah asli termoplastik daripada NR/LLDPE yang diperkuat gentian Twaron telah dijalankan melalui proses adunan leburan. Dua kaedah penyediaan yang berbeza digunakan iaitu menggunakan mesin pencampur dalaman manakala kaedah kedua menggunakan pengekstrud skru kembar. Kandungan Twaron di dalam komposit telah diubah daripada 0 hingga 30%. Keputusan menunjukkan bahawa penambahan Twaron telah meningkatkan nilai tegasan maksima, modulus Young dan kekuatan hentaman komposit tetapi menurunkan nilai terikan maksima. Kandungan Twaron yang optimum adalah 20%. Kehadiran Twaron telah membentuk satu jaringan saling tindak gentian-matriks menyebabkan kekuatan regangan komposit meningkat. Twaron juga berfungsi sebagai penyerap hentaman yang berkesan. Penyediaan komposit menggunakan pengekstrud skru berkembar telah menghasilkan nilai kekuatan regangan yang lebih tinggi berbanding penggunaan pencampur dalaman sebaliknya kekuatan hentaman yang lebih rendah. Kajian morfologi menggunakan mikroskop imbasan elektron mendapati komposit yang disediakan menggunakan pencampur dalaman menghasilkan gentian dengan orientasi rawak manakala pengekstrud skru kembar menghasilkan orientasi gentian yang selari. Keputusan ini menunjukkan bahawa sifat mekanik komposit NR/LLDPE yang diperkuat Twaron sangat dipengaruhi oleh teknik pemprosesan.
Serbuk sekam padi (SP) merupakan serabut semula jadi yang boleh bertindak sebagai pengisi penguat dalam adunan getah asli termoplastik (TPNR) NR/HDPE selepas permukaan serbuk dimodifikasikan sewajarnya. Rawatan serbuk SP merangkumi pra-rawatan dengan 5% larutan natrium hidroksida (NaOH), rendaman dalam larutan getah asli cecair (LNR) dan dedahan SP tersalut LNR kepada sinaran electron (EB). Komposit TPNR/SP disediakan secara pengadunan leburan dalam pengadun dalaman pada keadaan yang telah ditentupastikan terlebih dahulu. Morfologi komposit yang dianalisis menggunakan mikroskop elektron imbasan (SEM), menunjukkan taburan zarah pengisi SP termodifikasi adalah homogen dan kewujudan interaksi matriks-zarah. Komposit terisi SP terubahsuai LNR-EB menunjukan perubahan sifat mekanik yang ketara. Nilai maksimum tegasan dan kekuatan impak adalah masing masing 6.7 MPa dan 13.2 kJ/cm2 pada dedahan 20 kGy dos EB, manakala modulus regangan adalah 79 MPa pada dos 30 kGy. Ini menunjukkan terdapat peningkatan interaksi berkesan antara-muka SP dan TPNR bagi SP terwat LNR pada dos 20-30kGy EB. Peningkatan dos EB pada SP tersalut LNR menyebabkan degradasi salutan NR dan meningkatakan interaksi antara zarah SP. Pengaglomerasian zarah SP akan berlaku dan menyebabkan serakan zarah dalam komposit menjadi tidak homogen.
Sistem hidrazin hidrat/hidrogen peroksida (HH/H2
O2
) digunakan untuk menjana sumber hidrogen bagi tujuan
penghidrogenan getah asli cecair (LNR) melalui penghasilan diimida. Spesies diimida yang terhasil akan membekalkan
sumber hidrogen kepada ikatan karbon ganda dua dalam rantai polimer LNR. Getah asli cecair terhidrogen (HLNR)
yang terhasil menunjukkan ciri lebih tahan suhu berbanding LNR. Suhu degradasi HLNR didapati meningkat pada 435°C
berbanding LNR iaitu pada 381°C. HLNR seterusnya dijadikan pengserasi dalam penghasilan adunan polimer polistirena/
getah asli, PS/NR/HLNR (60/35/5). Kekuatan regangan dan impak PS/NR masing-masing meningkat sebanyak 70.7% dan
149.6% setelah HLNR ditambah sebagai pengserasi dalam adunan. Beberapa pemerhatian morfologi melalui mikroskop
optik dan SEM turut menyokong kesan penyerasian adunan PS/NR dengan HLNR.
The aim of this study is to investigate the factors that cause landslides in the area along the new road between Cameron Highlands and Gua Musang. Landslide factors such as lineaments have been extracted from remote sensing data (Landsat TM image) using ERDAS software. A soil map has been produced using field work and laboratory analysis, and the lithology, roads, drainage pattern and rainfall have been digitized using ILWIS software together with the slope angle and elevation from the Digital Elevation Model (DEM). All these parameters, which are vital for landslide hazard assessment, have been integrated into the geographical information system (GIS) for further data processing. Weightage for these landslide relevant factors related to their influence in landslide occurrence using the heuristic method has been carried out. The results from this combination through a modified ‘index overlay with multi class maps’ model was used to produce a landslide hazard zonation map. Five classes of potential landslide hazard have been derived as the following: very low hazard zone 17.27%, low hazard zone 39.35%, medium hazard zone 25.1%, high hazard zone 15.35% and very high hazard zone 2.93%. The results from this work have been checked through the landslide inventory using available aerial photos interpretation and field work, and show that the slope and elevation have the most direct affect on landslide occurrence.
Blends of fiber-reinforced rubber (FRR) based on natural rubber-thermoplastic (NR/LLDPE) and epoxidized natural rubber Âthermoplastic (ENR/LLDPE) reinforced by aramid fibre have been done using melt blending process. Twaron aramid fibres (Teijin-Twaron) used in this project were treated with epoxy adhesion activated and resorcinol formaldehyde latex (RFL). It was found that with increasing amount of aramid fibre led to increase the maximum stress, tensile modulus, impact strength and hardness of the composites while the strain at break decreased rapidly. The results show that the optimum composition of filler loading in NR/LLDPE blend is 20%. However, in the case of the ENR/LLDPE composite, the tensile strength and modulus increase with increasing amount of the fibre above 20%. The results indicate that the interfacial adhesion between ENR/LLDPE and aramid is better than for the NR/LLDPE.
[Penyediaan adunan getah asli termoplastik dan getah asli terepoksida termoplastik yang diperkuat dengan gentian aramid telah dilakukan melalui proses adunan leburan. Gentian aramid yang digunakan adalah gentian pendek Twaron (Teijin-Twaron) yang dirawat dengan bahan pelekat epoksi dan resorcinolformaldehid latex (RFL). Hasil yang diperolehi menunjukkan bahawa kesan penambahan gentian aramid telah meningkatkan tegasan maksima, modulus regangan, kekuatan hentaman dan kekerasan kedua-dua adunan tersebut tetapi menurunkan nilai terikan pada takat putus. Bagi adunan NR/LLDPE didapati komposisi gentian yang paling optima adalah pada 20%. Penambahan gentian aramid seterusnya hanya menurunkan sifat mekanik adunan. Sebaliknya bagi adunan ENR/LLDPE, didapati komposisi gentian melebihi 20% masih menunjukkan peningkatan tegasan maksima dan modulus regangan. Keputusan ini menunjukkan bahawa interaksi antaramuka gentian aramid dan matriks dalam adunan ENR/LLDPE lebih baik berbanding NR/LLDPE].
It is normally agreed that medicinal plants and their products are safer than their artificial counterparts; nevertheless, some plant products may show efficacious but have low therapeutic index or safety margin. Carica papaya fruits, leaves, seed and latex are used medicinally for various types of ailments. The Non-Steroidal Anti-inflammatory drugs nowadays are not useful in all cases because of their side effects which is associated with gastric irritation, bleeding, and ulcers. This study was considered to assess the effectiveness of methanol extract of Carica papaya seeds as compared to the treatment alternative of the Non-Steroidal Anti-inflammatory drugs which is indomethacin 50mg/kg. Objective: The main objective is to know the effectiveness of the anti-inflammatory effect of the methanolic extract of Carica papaya seeds as compared to the treatment alternative of Non-steroidal anti-inflammatory activity-Indomethacin 50mg/kg. Method: The maceration method was used to extract the Carica papaya seeds by using Methanol, two different doses of extract of 250mg/kg and 500mg/kg were administered orally after inducing the paw edema using the 1% of carrageenan. Then, the length of the paw edema was measured by using veneer caliper. Results: In the rat paw edema model, 500mg/kg of Carica papaya seeds shows 71.43%, 250mg/kg shows 63.91% and standard Indomethacin 50mg/kg treatment showed 88.72% of percentage inhibition. The results are statistically analyzed using One Way ANNOVA test. Conclusion: Post hoc analysis using Effect Scheffe test shows significant difference between group 1 and group 2, 3 and 4 (p ˂ 0.001) respectively at all time. The results showed it is significant value (p< 0.001) for the Methanolic extract of Carica papaya seeds regardless of its doses.