【作者】 何立红；

【导师】 赵京波；

【作者基本信息】 北京化工大学 ， 高分子化学与物理， 2002， 硕士

【摘要】 脂肪族聚酯因具有良好的生物相容性、生物降解性和无毒性，而被广泛用作可生物降解材料和药物缓释体系的载体。对于可生物降解聚酯的研究也成为近几年来的一个热点。脂肪族聚酯可由一系列内酯通过活性开环聚合制得。内酯化合物主要有：β-丙内酯、γ-丁内酯、δ-戊内酯、ε-己内酯、ω-辛内酯、乙交酯和乳交酯等。其中研究的最普遍的是己内酯、乳交酯、乙交酯等。对于它们的研究，除了进行均聚或几种单体共聚(如嵌段)外，近年来对单体接枝到其它基体，制得具有特殊性能的聚合物的研究的也比较多。 本课题采用阴离子型的引发剂萘钠，在几种基体上以羟基为接枝点进行接枝聚合。所选用的基体为部分乙酰化的淀粉、羟基化的聚丙烯膜、水解的EVA膜以及部分水解的聚乙烯醇膜。在不同基体上的接枝聚合中，分别讨论了引入羟基和接枝反应的条件对接枝率的影响，并对产物进行了DSC、GPC、FTIR、ATR、NMR、SEM、ESCA测试和表征。 对于淀粉乙酸酯接枝聚己内酯，将淀粉在二甲基甲酰胺和吡啶存在下，以乙酸酐进行部分乙酰化，制备取代度为0.7～1.9的淀粉乙酸酯(St-Ac)，并对影响取代度的因素如乙酸酐及吡啶用量、溶剂化时间等进行了研究。以萘钠与淀粉乙酸酯中残余的羟基反应，将羟基转化为醇盐(—ONa)，引发己内酯进行阴离子开环接枝聚合，合成了淀粉—聚己内酯接枝共聚物(St-g-PCL)。采用凝胶渗透色谱法(GPC)研究了接枝前后聚合物分子量的变化情况，并以接枝率、单体转化率对接枝反应进行了表征。研究了接枝条件如温度、溶剂、引发剂和单体的用量对接枝率及单体转化率的影响。研究发现随着反应温度升高，接枝率、单体转化率呈S曲线变化，单体浓度、引发剂浓度的增大有利于接枝反应的进行。同时对接枝产物以DSC、NMR、FTIR进行了表征，北京化工大学硕士学位研究生毕业论文 对于聚丙烯膜，采用BPO一氧化一皂化法、光反应法和氧化一还原法(HZoZ一NaHso3、HZoZ一三乙醇胺)在PP膜上引入轻基，确定了氧化还原法是弓I入轻基的一种比较可行的方法。讨论了反应时间、乳化剂的类型和溶剂对膜上引入经基量的影响，并以水接触角研究了轻基化膜的亲水情况。以蔡钠、二辛酸锡为引发剂，对轻基化膜进行本体和溶液接枝聚合。将接枝产物进行ATR、FTIR、SEM测试，定性地说明在膜上形成聚己内酷的接枝链，也间接地说明在膜上能用氧化还原法引入经基。 对于EVA的接枝反应，将EVA膜水解后，以蔡钠引发进行接枝聚合，讨论了溶剂化时间、溶剂的类型和反应温度对接枝量的影响。将接枝前和接枝后的膜以FTIR进行表征，由谱图定性地说明在膜上引入聚己内酷。 对于PVA。的接枝反应，将单体醋酸乙烯聚合，控制水解，然后将部分水解的聚醋酸乙烯酷溶液制膜，再以蔡钠或二辛酸锡引发接枝聚合。讨论了不同水解度下的轻基量以及不同水解度下聚醋酸乙烯酷的溶解性。更多还原

【Abstract】 Aliphatic polyesters derived from lactic and glycolic acids have been used extecsively as biomaterials and carriers for drug delivery systems. Owing to their low toxicity, excellent biocompatibility and biodegradability, studies on them have resulted in a great interest of many researchers. Polyesters derived from the ring-opening polymerization of a series of lactones such as 3 -lactones , Y -lactones, 5 -lactones and ?-lactones and so on are biodegradable polymers. The extensively studied monomers among them are -caprolactone, lactide, glycolactide buryrolactone. Apart from the polymerization and copolymerization of monomers, the study on the grafting polymerization onto some substrates in order to obtain well defined polymers have gained much interest in recent years.In this paper, a anionic initiator naphthalene sodium was used to initiate the grafting polymerization on the substrates such as starch acetate, polypropylene film having -OH functional groups , EVA film and partially hydrolyzed PVAc film. The reaction conditions of forming -OH and grafting polymerization on every substrates were studied and the graft polymers were characterized by DSC, GPC, FTIR, ATR, NMR, SEM, ESCA.Using pyridine and N,N-dimethylformide (DMF) as an activator, and starch acctatc(St-Ac) with substituting degree (DS) about 0.7-1.9 was obtained. The effect of the solvating time by DMF and quantity of acetic anhydride on DS was studied. Graft polymerization -caprolactone ( -CL) onto starch acetate was carried out through anionic ring-opening polymerization of -CL in diethylene glycol dimethyl ether solution. The graft polymerization was initiated by -ONa groups which were formedthrough the reaction of the remained -OH groups in St-Ac with naphthalene sodium (NS). The grafting reaction was characterized by grafting percentage, monomer conversion, as well as gel permeation chromatography (GPC) through comparison of the Mn, Mw and Mw/Mn of St-Ac with that of the grafted copolymer, starch grafted polycaprolactone (St-g-PCL). The influence of the reaction temperature, monomer and NS concentrations on the grafting percentage and the monomer conversion was discussed. The results showed that the grafting percentage and the monomer conversion vary in a way of S curves as grafting temperature increased from 50’C to 150*C, but increase with the increasing of the monomer concentration and NS concentration. The graft copolymers obtained are also characterized by DSC.NMR and FTIR.This paper also describes the methods to synthesize new graft copolymers such as polypropylene-graft-polycaprolactone(PP-g-PCL), ethylene/vinylacetate-graft-polycaprolactone ( EVA-g-PCL ) and poly(vinyl alcohol)--graft-polycaprolactone (PVA-g-PCL) using commercial polypropylene film, EVA film and PVA film as substrates, on which were introduced some hydroxyl groups Introduction of the hydroxyl groups to the PP, EVA and PVA films is the key step to synthesize PP-g-PCL, EVA-g-PCL and PVA-g-PCL. To introduce the hydroxyl groups onto the PP film, several methods including redox reaction of H202 -NaHSO3, H2O2 -N(CH2CH2OH)3, BPO oxidation and followed saponification, ultraviolet light excited oxidation initiated by BP are taken, the resulted hydroxyled PP film were characterized by FTIR and UV spectra and water-contact angle. The hydroxyl groups onto the EVA film were introduced by the hydroxylation reaction.The graft copolymerization of caprolactone onto the hydroxylated PP and EVA films was carried out using naphthylene-sodium as initiator. The grafting reaction was characterized by grafting percentage, FTIR spectra,. SEM and ATR.更多还原