Compatibility And Degradability Of Kenaf-Filled Linear Low Density Polyethylene Polyvinyl Alcohol Composites

The research on natural fibres polymer composites are rapidly growing due to an increasing demand on environmentally friendly polymer products with reasonable price. The on-going efforts are focused on the improvement in overall properties of these composites. In this research work, linear low-density polyethylene (LLDPE)/poly (vinyl alcohol) (PVOH) blend were utilized as polymer matrices with a fixed composition at 60/40 (wt. %), whereas kenaf bast fiber (KNF) was used as filler. The effect of filler loading, as well as various chemical treatments on the natural filler towards the processing characteristic, tensile, structural, morphological, thermal and biodegradability properties of LLDPE/PVOH/KNF composites were explored. LLDPE/PVOH/KNF composites containing different KNF loadings (i.e. 0, 10, 20, 30 and 40 phr) were prepared by means of melt-mixing and compression moulding. It was found that with increasing KNF loading, the processing torque, tensile modulus, thermal stability and water absorption of composites were increased. Nevertheless, tensile strength and elongation at break of composites were found declined. This indicated weak interfacial adhesion between LLDPE/PVOH matrices and KNF, as revealed by SEM studies. Natural weathering and soil burial has affected the properties of LLDPE/PVOH/KNF composites, as displayed by the deterioration in tensile properties, damage of exposed surfaces, and higher percentage of weight loss. Results from FTIR spectra further confirmed the occurrence of degradation with appearance of intense carbonyl peaks. The existence of chemical treatments of KNF has enhanced the tensile, morphological and thermal properties, as well as reduced the water absorption of LLDPE/PVOH/KNF composites. The chemical treatment of KNF was further confirmed by FTIR spectroscopy. Based on the results, it was found that addition of 3- (trimethoxysilyl)propyl methacrylate (TMS) treated KNF into LLDPE/PVOH matrices has increased the processing torque, tensile strength, tensile modulus, thermal stability and reduced the water absorption of the composites. This was evidenced by the enhanced interfacial adhesion between TMS-treated KNF and LLDPE/PVOH matrices in SEM analysis. Addition of treated KNF with eco-friendy coupling agent (EFCA), chromium (III) sulfate and lysine into LLDPE/PVOH matrices were found respectively increased the processing torque, tensile properties, thermal stability and reduced the water absorption of composites. Results from SEM analysis revealed an improvement in the interfacial adhesion between treated KNF and LLDPE/PVOH matrices. FTIR results also confirmed that chemical bonds were formed between coupling agents and KNF, subsequently provide linkages between KNF and LLDPE/PVOH matrices

Preparation, Characterization And Properties Of Polypropylene/Waste Tyre Dust/Kenaf Powder Composites

Thermoplastic elastomer composites of polypropylene (PP)/waste tyre dust (WTD)/kenaf powder (KNFp) were prepared with a fix thermoplastic elastomer blend composition of PP/WTD at 70/30 (wt./wt.%). The amount of KNFp used in this research was 0, 5, 10, 15 and 20 phr. All composites were prepared using a Thermo Haake Rheomix Polydrive R600/610 internal mixer at temperature of 180°C and rotor speed of 50 rpm for a mixing time of 10 minutes. The results showed that the stabilization torque, tensile modulus, water uptake and thermal stability of composites increased with increasing KNFp loading. However, the tensile strength and elongation at break was decreased. By substituting KNFp with kenaf short fiber (KNFs), the tensile strength and tensile modulus of the composites were higher. However, the increasing in processing torque causes a difficulty during preparation of the PP/WTD/KNFs composites. Addition of 3-aminopropyltriethoxysilane (APTES) to the composites has resulted in higher stabilization torque, tensile strength and tensile modulus, whereas the elongation at break and water uptake were lower. APTES was found to be effective to act as coupling agent due to the enhancement in interfacial adhesion of the composites, as shown by the SEM micrographs. For PP/WTD/KNFp composites with the addition of phthalic anhydride (PA), tensile strength, tensile modulus and water uptake were increased, but the elongation at break and processing torque were decreased

Influence of Kenaf (KNF) Loading on Processing Torque and Water Absorption Properties of KNF-Filled Linear Low-Density Polyethylene/Poly (vinyl alcohol) (LLDPE/PVA) Composites

AbstractThe KNF-filled linear low-density polyethylene composites were prepared by using an internal mixer (Thermo Haake Polydrive) at 150°C and 50rpm rotor speed. The composites were mixed with different KNF loading, i.e., 10, 20, 30 and 40 phr. The effects of KNF loading on processing torque and water absorption of the composites were investigated. The results indicated that stabilization torque and water absorption were increased with increasing KNF loading. Composites with higher KNF loading demonstrate higher equilibrium water absorption

Linear low density polyethylene/poly (vinyl alcohol)/kenaf composites: effect of natural weathering on functional group, weight loss characteristics, tensile, morphological and thermal properties

The development of natural fiber polymer composites is increasing worldwide and in some applications, these composites are used at outdoor rendering them exposed to ultra-violet (UV) radiation. The paper investigates the degradation behavior of linear low density polyethylene/poly (vinyl alcohol)/kenaf (LLDPE/PVOH/KNF) composites after exposure to different natural weathering durations. The composites with KNF loadings of 10, 20 and 40 parts per hundred resin (phr) were exposed to natural weathering for 3 months and 6 months, respectively. The weathered composites were characterized by Fourier transform infrared (FTIR) spectroscopy, universal testing machine, field emission scanning electron microscopy (FESEM) and differential scanning calorimetry (DSC). The FTIR analysis showed an obvious carbonyl peak in composites after weathering as an evidence of oxidation. The weight loss percentage of composites increased with respect to exposure duration due to higher absorption of UV irradiation. The tensile properties of weathered composites were lower than that of control composites and these properties also decreased with increasing exposure duration. FESEM micrographs illustrated that composites with longer exposure duration suffered more surface damaged. The crystallinity percentage was found to increase with increasing exposure duration

DNA Genotyping of Borneo Ironwood using M13 Universal Primer and SCAR Marker Development in Eusideroxylon zwageri

Borneo Ironwood, consists of two species, i.e. Eusideroxylon zwageri and Potoxylon melagangai, is the most well known durable tropical hardwood timber tree of Borneo. Both species are morphologically similar, except the wood characteristics. This has resulted in taxonomic difference between them. We used PCR with M13 universal primer to determine the genetic relatedness and SCAR marker to distinguish both species. Cluster analysis grouped both species into two major clusters, suggesting that there are two genetically distantly related species. One diagnostic band (locus M13-16) was successfully converted to SCAR marker. A single fragment (720 bp) was amplified in all E. zwageri individuals but completely absent in P. melagangai. Differentiating the species by SCAR marker is very useful for screening large numbers of Borneo Ironwood seedlings collected from natural populations. The identification of individuals at species level constitutes one of the first basics in any effective conservation programme. In fact, the Borneo Ironwood has been counted as one of the endangered species in Sarawak