Study On Sorbide Polymers Based On Group Transfer Polymerization

Sorbic acid is a preservative widely used in various fields of social life.It can effectively inhibit the growth of various molds and aerobic fungi,with extremely low toxicity to humans,and is widely used.However,with the increase in application fields and environmental complexity,the anti-corrosion performance of sorbic acid is greatly discounted.In order to solve this problem,people began to study sorbic acid amide polymers.Sorbic acid amide polymers have the structural characteristics of sorbic acid,as well as the characteristics of high stability and strong applicability.This makes the functions of these polymers more diverse and can be widely used in various fields such as biomedicine,food,cosmetics,biochemistry and so on.Therefore,in order to meet the widespread demand and research value of sorbide applications,it is of great significance to explore the synthesis and application of sorbide polymers.In this paper,group transfer polymerization（GTP）is used to prepare sorbide polymers.The polymerization method is active/controllable,making it easier to prepare the required polymers.At the same time,it also provides a new research idea for the preparation of sorbamide polymers with different structures,such as random copolymers and block polymers.The specific content of this study is as follows:1.Firstly,the initiator triethylsilyl vinyl ketone acetal(SKA^Et)was synthesized.Using diisopropylamine to react with n-butyl lithium to obtain diisopropylamino lithium,methyl isobutyrate and triethylchlorosilane are added to this reaction,and SKA^Etis obtained after final purification.Secondly,the monomer N,N-diethyl sorbide（DESAm）was synthesized by the acyl chloride method.The first step of synthesis is the reaction and purification of sorbic acid with sulfoxide chloride to obtain sorbyl chloride.The second step of synthesis is the reaction and purification of sorbyl chloride,diethylamine,triethylamine,and dichloromethane to obtain the monomer DESAm.The structure of the synthesized initiator and monomer was characterized by hydrogen and carbon NMR spectroscopy.2.Using GTP method,explore the use of different initiators,organic small molecule catalysts,and solvents to prepare poly（N,N-diethyl sorbide）（PDESAm）,and characterize the structure of the prepared polymer.PDESAm was prepared using two initiators,SKA^Meand SKA^Et,an organic base catalyst,phosphonitrile base t-Bu-P₄,a toluene system,and an initiator,SKA^Meand SKA^Et,an organic acid catalyst,Me₃Si NTf₂,and dichloromethane system.The structure of the polymer was characterized using nuclear magnetic resonance spectroscopy,and the molecular weight and molecular weight distribution of the polymer were measured using a size exclusion system（SEC）.3.Through the GTP method,the catalyst is an organic base catalyst,phosphonitrile base t-Bu-P₄,the initiator is SKA^Me,and the solvent is toluene.The acrylate monomers methyl methacrylate（MMA）,tert butyl acrylate（tBA）,and n butyl acrylate（nBA）are used for block polymerization and random copolymerization with the monomer DESAm.In the same reaction system,the sorbate monomer ethyl sorbate（ES）and the acrylamide monomer N,N-diethylacrylamide（DMAm）were used for block polymerization and random copolymerization with the monomer DESAm.The structure of the polymer was characterized by hydrogen spectroscopy,and the molecular weight and molecular weight distribution of the polymer were measured by SEC.The dispersibility index（PDI）was around 1.20.A polymer with a clear structure and a narrow molecular weight distribution was successfully prepared.