UNSATURATED POLYESTER FRACTURE TOUGHNESS MECHANISM WITH BLENDING TO VINYL ESTER AND MMA

Abstract

In this research, a method was used to increase the brittleness of unsaturated polyester polymer by mixing it with vinyl ester. The choice of vinyl ester to increase the toughness of this polyester is because it is easy to form and this material has wide applications in engineering. However, this polyester has several weaknesses, namely, it is very stiff, brittle, and unable to withstand cracking loads and breaks easily due to impact. Polyester has a rigid nature because this material has cross-chain links of material that are tightly locked and interconnected with each other. With the addition of this vinyl ester, this tightly connected rigid chain is disrupted by the vinyl ester chain, thereby increasing the toughness of the polyester. Steps were taken to increase the crack resistance of unsaturated polyesters with the addition of vinyl esters, starting with the percentages of 10%, 20%, 30%, and 40% and comparing them with pure polyester. The results obtained showed that the crack resistance of polyester increased with the addition of 40% wt vinyl ester. The results show that the highest fracture toughness value is indicated by the value of the stress intensity factor ofK1c=1.752 MPa.m0.5.