Mechanical properties and water absorption of glass fibre reinforced bio-phenolic elastomer (BPE) composite

• Epoxidised natural rubber (ENR) was used to toughened glass fibre reinforced bio-phenolic resin composites.
• The ENR has served as a compatibiliser between glass fibre and bio-phenolic resin.
• Impact strength of the composites increased as ENR mole % of epoxidation and composition increased.
• Water absorption of the bio-phenolic elastomer composites reduced as the composition of ENR introduced was increased.

In this study, bio-phenolic resin (BPR) was synthesised using liquefied oil palm empty fruit bunch (EFB) fibres. Epoxidised natural rubber (ENR) was added to provide elastomeric properties and improve the phenolic resin brittleness. Three different types of NR/glass fibre prepregs using SMR-L, ENR-25 and ENR-50 were prepared and used in the fabrication of the bio-phenolic elastomer (BPE) glass composites. The composites were made by using hand lay-up technique. The ENR-50 showed the best compatibility with the BPR. The impact strength of the composites increased as much as 77.7% with the addition of 35 wt% of ENR-50. Flexural test results indicated that the BPE composites possessed elastomeric properties. The ENR acted as a compatibiliser that helped in improving the wettability of the BPR on the surface of the glass fibres. Furthermore, approximately 47% of water absorbed by the BPE composites was reduced as the ENR-50 composition increased up to 35 wt%.