结构和性能可控的淀粉接枝醋酸乙烯酯及淀粉接枝聚乙烯醇水凝胶的制备.pdf

华侨大学
硕士学位论文
结构和性能可控的淀粉接枝醋酸乙烯酯及淀粉接枝聚乙烯醇水
凝胶的制备
姓名:卢德荣
申请学位级别:硕士
专业:高分子化学与物理
指导教师:萧聪明
20100601
摘要
摘要
可逆-断裂链转移聚合作为一种方便而有效的活性自由基聚合(LCP)用于醋
酸乙烯酯(VAc)聚合｡成功地制备了淀粉基黄原酸酯链转移剂用于调控 VA c 的活
性自由基聚合｡GPC 结果显示,聚合产物淀粉接枝聚醋酸乙烯酯(SVAc)侧链分子
量可控且分子量分布较窄｡SVAc 醇解成相应的淀粉接枝聚乙烯醇(SVA),并通过
冷冻-解冻的物理交联法制备了不同侧链分子两的 SVA 水凝胶｡
通过红外光谱分析(FTIR),核磁共振分析(NMR)以及热重分析(TGA)确定了
SVAc 和 SVA 的结构�证明了聚合产物和醇解产物为目标产物
接触角测试确定了 SVAc 接枝聚合物的双亲性,接触角测试的结构表明 SVAc
亲疏水性可以通过控制 SVAc 侧链分子两来调控｡通过双亲性自组装在水溶液中
制备了 SVAc 纳米胶束｡采用透射电镜确定了纳米胶束的结构,并用动态光散射仪
分析了不同侧链分子两的 SVAc 胶束的粒径分布,结果表明,SVAc 纳米胶束的粒径
也可由侧链分子量来调控｡
结构可控的 SVA 水凝胶采用动态热机械分析仪(DMTA)以及 X 射线衍射
(XRD)来分析其动态粘弹性能与结晶度｡DMTA 结果表明,SVA 水凝胶存在典型的
凝胶的特征,确定了冷冻-解冻物理交联水凝胶能够形成稳定的水凝胶,同时也改
善了淀粉凝胶的一些性能｡此外 SVA 水凝胶的存储模量,损耗模量均随分子量的
增大而增大即可通过侧链分子量来调控｡XRD 测试的结果也符合这个趋势,SVA
水凝胶的结晶度也可有侧链分子量来调控｡
结构和性能可控的 SVAc 和 SVA 水凝胶已经通过 SXA 调控的 RAFT 活性自
由基聚合成功制备,SVAc 和 SVA 的性能可通过调控侧链分子量来实现可控的目
的｡

关键词: RAFT, 结构和性能, 可控, SVAc,SVA
I
ABSTRACT
ABSTRACT
RAFT polymerization was adopted as a convenient approach to render
starch-based polymer controlled architecture and enhanced functionality. Starch-based
xanthates agent was prepared and applied as chain transfer agent to conduct the
living/controlled polymerization (LCP) of vinyl acetate, by which tailor-made
conjugates (SVAc) of starch and well-defined polyvinyl acetate were formed. The
relevant derivatives (SVA), conjugates of starch and chain length-controlled polyvinyl
alcohol, were obtained subsequently. Various characterizations such as FTIR,
1HNMR, GPC, XRD, TGA, and DMTA were performed to examine the structures of
intermediates and the starch-based polymers. Contact angle measurements revealed
that hydrophilic or hydrophobic property of starch-based polymers would be tunable.
Well-defined SVAc was amphiphilic and able to self-assemble into size controllable
micelles, which was verified with TEM and DLS tests. SVA was capable of forming
physically cross-linked hydrogel, which greatly i