Study On The Mechanics Performance Of Thermoplastic Resin CBT And Its Composites

Composite materials have been widely used in civil engineering,marine and aerospace with the advantages of high specific strength,lighter quality and corrosion resistance.However,environmental protection organizations in the word have been established some related policies to limited thermoset composites used in engineering field in recent years because of its unrecoverable,for example the European Union established a restricted system of glass fiber reinforced plastic products.Compared with thermoset composites,thermoplastic composites can be recycled,but the problem of the high processing viscosity seriously hampered its development.As a new type of thermoplastic resin,cyclic butylene terephthalate(CBT)has a low viscosity which just likes water at a certain temperature and in the polymerization process no heat and harmful gases release of.With the advantages,CBT has broad prospects in engineering application in the future.In this paper,the mechanical properties of the new type of CBT resin and its composites were studied,and comparative analysised the changes of the mechanical properties under different experimental environment.The main contents of this papaer include the following three parts:(1)Through the experiment method,the mechanical properties of CBT(polymerization)resin under different hot and humid environment were studied.In order to make pCBT(CBT after polymerization)have the best performance,first of all,the most suitable amount of catalyst in the CBT polymerization reaction was studied;then the pCBT specimens with the optimal catalyst content were placed in four different hygrothermal aging experiments,after that carried on the compressive strength for the specimens from experimental research were carried on.The research results show that hot and humid environments have a great influence on mechanical properties of pCBT resin;according to the several kinds of commonly prediction method,the service life of Pcbt was predicted.(2)The pCBT/GF composite materials was prepared with vacuum assisted resin injection process(VARI)and vacuum assisted molding process(VARTM),and the influence mechanism of the preparation process with diffrerent preparation parameters was given.This part also analyzed the applicability of the two different Preparation processes(3)This part studied on the mechanical properties changes of the GF/pCBT under salt-immerion and salt-spray(40?)experimental environment.Througth the mechanical test of specimens after experiments,the mechanical properties changes curves with experimental time increasing were given.