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Preparation and Research on Molecular Weight Structure of Poly(l-lactide) via Solvothermal Method

Author: FangLing
Tutor: QiZuoZuo；ZhangPing
School: Shanghai Jiaotong University
Course: Chemical Engineering
Keywords: Poly(L-lactide) PLA solvothermal anti-oxidant molecular weight crystallization
CLC: O633
Type: Master's thesis
Year: 2009
Downloads: 14
Quote: 2
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Abstract


Poly(L-lactide) is obtained from lactide polymerization. It posseses excellent biocompatibility, biodegradable, high strength and easy to process. Currently the preparation of PLA could be divided into direct method and indirect method. Either of them needs high reaction temperature, high vacuum degree and long reaction time. Due to such limitations, the reaction stability is poor and the percent conversion is low which make it difficult to synthesize PLA with high molecular weight. Solvothermal process, by improving the polymer’s dissolvability and reactivity in a sealed system, is special to synthesize the polymers which are hardly got under traditional react conditions. The previous research work carried in our lab has successfully polymerized the PE, SBS and ABS highly grafted by maleic anhydride via solvothermal process. Trying to better understand the application of solvothermal method and find a new method to prepare poly(L-lactide), in this paper, L-lactide as monomer and SnCl2 as catalyst were used to synthesize PLA polymer. The effects of catalyst, reaction temperature and reaction time on polymerization were evaluated to find the optimized reaction station to get the high molecular weight PLA. The effect of three different solvents and anti-oxidant on molecular weight and crystallization of PLA have also been discussed. The effect of co-monomer on PLA polymerization was also evaluated.

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CLC: > Mathematical sciences and chemical > Chemistry > Polymer chemistry ( polymer ) > Miscellaneous Chain Polymers
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