Methods for increasing fracture toughness of thermosetting polyester polymers with vinyl ester mixtures as raw materials for automotive components

Abstract

Unsaturated polyester is a polymer that is widely used as a basic matrix to form strong composites for engineering applications such as cars, ships, aircraft and other field applications. The advantages of this material are that it has a fairly high tensile strength when reinforced with appropriate reinforcement and is light and easy to shape. However, the weakness of this polymer is that it is brittle and cannot withstand shock loads. To do that, it is necessary to overcome the nature of the weaknesses mentioned above. One of the materials chosen to strengthen polyester with the vinyl ester is because these polymers have almost identical molecular bonds. A crack test was carried out on the addition of vinyl ester with a different composition process. To find out whether this vinyl ester can increase the crack strength of unsaturated polyester and to find out what percentage of the mixture has good crack resistance properties. To determine the value of the crack resistance of the polymer mixture with vinyl ester, a crack resistance test was carried out which would produce a large critical stress intensity factor based on ASTM D 5405 by varying the composition of the polyester and vinyl ester mixture from (0%/100%, 70%/30%, 30%/70% and 0%/100%). From the test results, the greatest critical stress intensity factor occurs in a mixture with a composition of 30% Polyester and 70% vinyl ester of 1.752 MPa.m0.5. The critical stress intensity factor increased from 0.762 MPa.m0.5 to 2.179 MPa.m0.5 (2867% increase) for pure UP.