Preparation Of Plant Oil Monoglyceride And Research On Synthesis And Properties Of Unsaturated Polyester

General unsaturated polyester is a kind of high-performance thermosetting polymer materials, widespread application in industry, agriculture and national defense and so on. As far as the environmental protection and reduction of petroleum resources are considered, the use of renewable resources in the preparation of various industrial materials has been revitalized. In this paper, unsaturated polyester resin (UPR) was prepared from vegetable oil. This study develops a kind of new modified unsaturated polyester with excellent properties of high elongation ratio, good impact properties and flexibility.First, plant oil monoglyceride were obtained from the alcoholysis reaction between soybean oil and glycerol. After study on some important factors such as mole ratio of glycerol to plant oil, synthesis temperature and catalyst, the optimum condition of synthesis was determined. That was: mole ratio was 2.5 : 1, synthesis temperature was 220℃, 0.04% lithium hydroxide was served as catalyst and rate of production was 60%. The structures of the target compounds have been characterized by FT-IR spectroscopy and ¹H-NMR spectroscopy.Second, the intermediate product plant oil monoglyceride was used in synthesizing unsaturated polyester (UP) to partly replace 1,2-propanediol with maleic anhydride phthalic anhydride and the final UP was characterized by FT-IR and ¹H-NMR. Mechanical properties of the cured resin including flexural, tensile, extensibility and impact properties were also discussed. The results showed that curing heat liberation of UPR decline gradually with increasing SOMG concentrations. Storage modulus and tanδvalues as well as flexural strength, tensile strength also decrease while extensibility and impact strength improve and their values were 102.074KJ/m² and 27.69% respectively. Furthermore its flexibility was good and other mechanical properties satisfied the general operation requirements.Finally, dynamics factors analysis for resin synthesis gives out reaction progression, rate constant and macro reaction activity energy in these reactions. The main synthesis reaction was the second-level reaction and reaction activity energy were 79.69kJ·mol^-1, 85.81kJ·mol^-1, 105.2kJ·mol^-1 and 110.4kJ·mol^-1. The polyreaction kinetics equation was inferred and it is very useful to develop the modified unsaturated polyester resin.