Study On Synthesis Of New Unsaturated Polyester Resin

In this paper maleipimaric acid (shortened form MPA) was prepared using rosin that is abundant reproducible resource in china; Unsaturated polyester rosin (shortened form UPR) was synthesized by melt condensation polymerization, taking biatomic acids, diatomic alcohols and prepared MPA as main raw materials. By researching synthesis technics and properties of UPR we had synthesized new UPR. These results of the paper are important meaning to extend synthesis and modification methods of UPR. To use MPA partially or completely replacing phthalic anhydride (PA) to synthesize UPR will help to solve some shortcomings of rosin that are brought by phthalic anhydride and some problem that are brought by price fluctuation of phthalic anhydride.1. As triprotic acid MPA was prepared by addition reaction of rosin and maleic anhydride. Value acid and melting point of MPA were determined and IR chart of MPA was analyzed. The results indicated that purity of MPA is higher.2. Reaction parameter were ascertained by change of value acids: first step reaction went through 4 hour in 230~240°C; second step reaction went through 13.5 hour in 180— 185 °C; Catalyzer was Zn(AC)2, its dosage was 1.5% of MPA.3. by the uniform designing and determining the mechanical properties the optimum composition of new UPR was ascertained MPA:PA=1:3, MA:PA=1.3:1, DEG:PG=5:1. Analyzed by orthogonal testing experiments and determining the mechanical properties the optimum cure conditions of new UPR were ascertained as follows: use level of evocater (Benzoyl peroxide) is 2.0%, use level of accelerant (N,N-dimethylaniline) is 0.1%, content of crosslingking agent is 33%, solidification temperature is 45°C.4. By determining value acid, IR, TGA, storage time, mechanical properties, corrosion resistance and curing properties we researched the effect of MPA on structure and properties of new UPR, at the same time contrasted with commodity UPR. The results indicated that. (1) With reaction time increasing acid descended firstly fast secondly slow then immovably. With mol content of MPA increasing acid of product became more and more higher. (2) Analyse to IR chart indicated new UPR has similar structure to commodity UPR. New UPR had completely cured in the cure conditions of the paper. (3) TGA indicated with mol content of MPA increasing heat resistance of new UPR was...