Thesis (M.Eng.)--Chulalongkorn University, 2009

In this work the effects of glass fiber content and ethanol concentration in gasohols on the physical and mechanical properties of PVC/GF composites were studied. PVC resins with K-value of 58 (and other additives) were mixed with chopped E-glass fiber of 3 mm length at 0, 15, and 25 wt% using two-roll mill, then compressed into sheet, and cut into dumbbell shape, bar shape, block shape and disk shape specimens. The specimens were immersed into 4 different test fuels, namely C(E0)[subscritp A], C(E20)[subscritp A], C(E85)A, and C(E100)[subscritp A], prepared according to SAE J1681, in glass jars at room temperature for 16 weeks. The experimental results revealed relatively good dispersion of the glass fiber in the composites. The mechanical properties of PVC/GF composites increased with increasing glass fiber content. The mass and volume of PVC/GF composites increased due to absorption of iso-octane and toluene into PVC matrix. Test fuels with low ethanol content, namely, C(E0)[subscritp A] and CE(20)[subscritp A], caused the tensile strength, Young’s modulus, flexural strength and compressive strength of PVC/GF composites to decrease more but the impact strength to increase more than test fuels with high ethanol content, namely, C(E85)[subscritp A] and CE(100)[subscritp A], due to the reduction of mechanical properties of PVC matrix itself from absorption of iso-octane and toluene into PVC matrix. PVC/GF composites were not compatible with fuels with low ethanol content (≤ 20 vol%)