The objective of this research is a study to determine optimum forming condition of semi-finished bulk UHMWPE by using ram extruder that obtain maximum yield strength and minimum wear rate for apply to use in area of medical and mechanical application. Experimental extrusion specified forming condition consists of the temperature of 140 150 and 160 ºC and pressure of 3 5 8 and 10 MPa with the temperature exposure time of 30 minutes. After known optimum forming condition of UHMWPE powder thus forming UHMWPE filled with different kind of filler to study and determine optimum weight fraction of various types of filler that affect onto wear resistance property of UHMWPE composites. Result extruded condition at the temperature of 1 5 0 ºC under pressure of 5 MPa with exposure time of 30 minutes is an optimum extruded condition due to specimen shown a maximum yield strength ultimate tensile strength and elongation of 20.43 ± 1.21 MPa 28.33 ± 1.53 MPa and 285.60 ± 6.41 % respectively and obtain minimum wear rate of 3.02  10-9 ± 5.27  10-10 mm3/Nm. Its mechanical properties and wear resistance property higher than imported bulk UHMWPE by 23.3 % and 4.75 times respectively due to the formation of cross-linking are occurred in polymer chain and also its degree of crystallinity is high equal to 61.52%. For bulk UHMWPE IR-spectrum shown a variation peak of carbonyl group (C=O) are occurred that that it indicated the oxidation reaction at the end of polymer chain and tis degree of crystallinity is equal to 53.31% which result to decrease strength of polymer. In the case of UHMWPE filled with filler optimum weight fractions of various types of filler are as follows. 1. The filling of 0.3 wt. % Al2O3 particle size 0.05 μm shown yield strength ultimate tensile strength and elongation of 23.17 ± 3.35 MPa 34.78 ± 2.80 MPa and 229.00 ± 6.09% respectively that its mechanical properties was increased by 18.55% (increasing of ultimate tensile strength). For the wear rate is equal to 2.09  10-9 ± 3.39  10-10 mm3/Nm or its wear resistance was increased by 1.44 times in compared with initial bulk UHMWPE. 2. The filling of 0.4 wt. % Al2O3 particle size 0.3 μm shown yield strength ultimate tensile strength and elongation of 21.93 ± 0.51 MPa 25.40 ± 0.69 MPa and 267.67 ± 22.03% respectively that its mechanical properties was increased by 11.54% (increasing of ultimate tensile strength). For the wear rate is equal to 2.32  10-9 ± 4.78  10-10 mm3/Nm or its wear resistance was increased by 1.30 times in compared with initial bulk UHMWPE. ฉ 3 . The filling of 0.4 wt. % Al2O3 particle size 1 μm shown yield strength ultimate tensile strength and elongation of 23.93 ± 1.89 MPa 26.77 ± 1.20 MPa and 296.54 ± 7.51% respectively that its mechanical properties was increased by 5.83% (increasing of ultimate tensile strength). For the wear rate is equal to 2.14  10-9 ± 3.16  10-10 mm3/Nm or its wear resistance was increased by 1.41 times in compared with initial bulk UHMWPE 4 . The filling of 4 wt. % Al2O3 particle size 5 μm shown yield strength ultimate tensile strength and elongation of 22.57 ± 2.01 MPa 26.31 ± 3.11 MPa and 136.66 ± 11.67% respectively that its mechanical properties was increased by 7.68% (increasing of ultimate tensile strength). For the wear rate is equal to 2.37  10-9 ± 5.71  10-10 mm3/Nm or its wear resistance was increased by 1.27 times in compared with initial bulk UHMWPE

This research work was to study the effect of moisture on mechanical properties of wood/polyvinylchloride composites (WPVC). WPVC specimens in ratio of PVC and wood (100:100 by weight) were prepared by using twin screw extruder. The water conditions for WPVC specimen immersion testing were varied for temperatures of 30-70 oC and specimen immersion time of 0-120 h. The moisture effect was investigated by measuring flexural properties and hardness of WPVC as comparing with case of PVC specimen. The result suggested that flexural modulus of WPVC tended to decrease with increasing time of water immersion and then remained unchanged at immersion time of more than 72 and 48 h for water temperature of 30 and 70 oC respectively. The decrease rate in flexural modulus enhanced when water temperature increased. Flexural modulus of PVC slightly changed with increasing both immersion time and water temperature. Flexural strength for both PVC and WPVC specimens were found the change at water temperature of 70 oC only. Flexural strength of PVC tended to slightly increase with increasing immersion time whereas flexural strength of WPVC slightly decreased with increasing immersion time. Hardness of PVC specimen in cases of both water temperature of 30 and 70 oC slightly increased with increasing immersion time. For WPVC hardness tended to decrease with increasing immersion time and water temperature.

This research work was to study the effect of surface treatment of natural fiber and the effects of type and content of natural fiber on the development of acoustic material from natural rubber foam /natural fiber composites. The surface treatment used for this research work was sodium hydroxide (NaOH) treatment. NaOH Concentrations and treatment times were varied from 0 to 15 %wt. and 0 to 30 min respectively. Natural fibers used for this work were bagasse fiber (BF) and oil palm fiber (OPF). The suitable condition for surface treatment was estimated by fiber length and diameter (L/D) ratio and morphology of natural fiber. The result suggested that L/D ratios tended to increase when NaOH concentrations and/or treatment times increased except for NaOH concentration of 15 %wt. L/D ratios of OPF after surface treatment were changed more than those of BF. The suitable conditions of NaOH treatment for BF and OPF were NaOH concentration of 10 %wt. and surface treatment times of 30 and 10 min respectively. The effects of fiber type and content on sound absorption properties of natural rubber foam /natural fiber composites were investigated by cell characteristics sound absorption coefficient DMA analysis and bulk density. Both treated BF and OPF with suitable treatment condition were varied from content of 0.0 to 10.0 %wt. The result showed that the cell size of composites tended to decrease with addition of natural fiber whereas number of foam cell per unit volume increased. After adding natural fiber more than 2.5 %wt. cell size of composite foam and number of foam cell per unit volume tended to change the inverse direction. Natural fiber in composites enhanced the sound absorption efficiency. Sound absorption coefficient of composites adding BF was more than that of composite adding OPF. The addition of natural fiber enhanced the elasticity of composites and that increased sound absorption efficiency. NaOH treatment led to creation of strong interfacial bonding between natural fiber and natural rubber and enhanced the sound absorption efficiency. Density of NR composite foam increased with increasing natural fiber content.

This research work was to study the chemical release of wood/polyvinylchloride composites (WPVC) affecting the physical and chemical properties of water. WPVC specimens in ratio of PVC and wood (100:100 by weight) were prepared by using twin screw extruder. The water conditions for specimen immersion testing were varied for temperatures of 30-70 oC and specimen immersion time of 0-120 h. The water quality was estimated by measuring pH electrical conductivity turbidity and color of water after immersion of WPVC specimen as comparing with case of PVC specimen. The result suggested that pH values of water slightly decreased with increasing specimen immersion time whereas the change of temperature of water did not affect the pH value. The electrical conductivity remained unchanged with increasing specimen immersion time or temperature except for immersion of WPVC specimens at 70 oC. This might be attributed the weak interfacial bonds between PVC and wood and this led to more easily release the metal ions from additives of PVC. The turbidity and color of water for case of WPVC increased with increasing specimen immersion time whereas those for case of PVC did not change. From the results of water quality testing it indicated that WPVC applications which contact with water are safety. This was because water quality after immersion of WPVC specimen is within the effluent standards of pollution control department.

This research aims to study the application of coconut meal corncob and durian peel as wood-substituted biocomposites in medium density fiberboard. The fiber: urea formaldehyde glue: isocyanate glue with polymeric diphenymethane diisocyanate type (pMDI) ratio is equal to 1: 0.13: 0.003. The fibers are taken from coconut meal corncob and durian peel that 7 ratios are used to all of fiber mixing. The fiberboard production use 130?C of temperature with 20 – 50 kg/sq.cm of compressive pressure with 8 minutes per piece of rate. Their fiberboards have 603 – 856 kg/m of density that was tested follow the TIS 876-2547 standard. Resulting the MM33 ratio (coconut meal fibers: corncob fibers: durian peel fibers is equal to 0.33: 0.33: 0.33) and the CC50 ratio (coconut meal fibers: corncob fibers: durian peel fibers is equal to 0.50: 0.25: 0.25) can pass the standard in physical properties and mechanical properties. Moreover their fiberboards have good thermal insulation