Study On Unsaturated Polyester Resin Molecular Composites By Pre-in Situ Polymerization

Unsaturated polyester resin (UP) is one of the most important thermosetting resins, which has gained broad application such as in electrician-electron area because of cheap price and good handicraft function; but the low intensity and toughness have always restricted its applying. In order to satisfy various peculiar fields, the property of UP should be necessary improved. During the past few years, modified researches of UP were in the ascendant. Modified researches of UP have been developing to function-rization, refinement and high-performance direction at present. Though various method of modifying has advantages as well as disadvantages respectively, the copolymerization is a normal method which is researched mostly.There are lot kinds of UP, it is unrealistic to study on the modifying one by one within a certain time. In the research, we have chosen vinyl ester resin (VE) which is one kind of UP for modified research because of its much application, high performance and foreground developing of prospect. It has both common characters as one kind of unsaturated polyester resin and own characteristic property. Its handicraft function is similar to UP and its chemical structure is the same to epoxy resin, it is one kind of new model resin that gathering UP and EP's advantage. Therefore, it have applied broadly in the field of industry, agriculture, traffic, building and national defense industry, but there are also a lot of disadvantages that restrict its applying such as its low toughness and heat resistance. It is important for the study of improving Mechanics function as well as heat resistance of VE.The method which could modify EP is also proper for modifying VE, because VE has maintained EP's main link. The in situ polymerization technology is a new way for EP modifying, but there are many problems for VE modifying, because VE has unsaturated link which is not suitable for high temperature synthesizing, so we choose pre-in situ polymerization for VE modifying.We find the suitable RS as well as rigid polymer after synthesizing VE. The specialty of curing decides the process property, so we studied on the specialty of curing and confirmed the process which was 90°C/2h+110°C/2h+130°C/4h. The result shows that PEI/RS/VE cured resins are self-extinguished material; glass fiber /PEI/RS/VE composites are fire resistant material; the mechanic properties are best when PEI content is 7%, the flexural strength of PEI/RS/VE cured resin is 85.7MPa and the Impact strength is 7.2KJ/m2, the flexural strength of PEI/RS/VE composites is 311.6Mpa and the Impact strength is 106.9KJ/m2, the Morphologies of PEI modified VE are analyzed by Transmissivity, DSC and SEM, for PEI/RS/VE cured resin system, we could confer that it is belong to molecular composites when the content of PEI is below 7%, and it is belong to two Morphologies when the content of PEI is over 7%.