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Synthesis of comb-like copolymers from renewable resources: Itaconic anhydride, stearyl methacrylate and lactic acid.

机译：由可再生资源合成衣梳状共聚物：衣康酸酐，甲基丙烯酸十八烷基酯和乳酸。

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摘要

The synthesis and properties of comb-like copolymers and ionomers derived from renewable resources: itaconic anhydride (ITA), stearyl methacrylate (SM) and lactic acid (LA) are described. The copolymers based on ITA and SM (ITA-SM) were nearly random with a slight alternating tendency. The copolymers exhibited a nanophase-separated morphology, with the stearate side-chains forming a bilayer, semi-crystalline structure. The crystalline side-chains suppressed molecular motion of the main-chain, so that a glass transition temperature (Tg) was not resolved unless the ITA concentration was sufficiently high so that Tg > the melting point (Tm). The softening point and modulus of the copolymers increased with the increasing ITA concentration, but the thermal stability decreased.;The ITA moiety along the main chain of the copolymers was neutralized with metal acetates to produce Na-, Ca- and Zn- random ionomers with comb-like architectures. In general, the incorporation of the ionic groups increased the Tg and suppressed the crystallinity of the side-chain packing. Ionomers with high SM side-chain density had two competing driving forces for self-assembled nano-phase separation: ionic aggregation and side-chain crystalline packing. Upon neutralization, a morphological transition from semi-crystalline lamella to spherical ionic aggregation was observed by small angle X-ray scattering (SAXS) analysis and transmission electron microscopy (TEM). Thermomechanical analysis revealed an increasing resistance to penetration deformation with an increasing degree of neutralization and an apparent rubbery plateau was observed above Tg.;A controlled transesterification of PLA in glassware was an effective way to prepare a methacrylate functionalized PLA macromonomer with controlled molecular weight, which was used to synthesize a variety of copolymers. The copolymerization of this functionalized PLA macromonomer with ITA totally suppressed the side-chain crystallinity for the PLA chain length range studied. An increase of Tg was observed for sufficiently high neutralization level. The kinetics of ionic aggregation in this ionomer was very slow, but annealing at elevated temperature helped to reach equilibrium of the microstructure.
机译：描述了可梳状共聚物和离聚物的合成和性质，这些共聚物和离聚物来自衣康酸酐（ITA），甲基丙烯酸十八烷基酯（SM）和乳酸（LA）。基于ITA和SM的共聚物（ITA-SM）几乎是无规的，具有轻微的交替趋势。共聚物表现出纳米相分离的形态，其中硬脂酸酯侧链形成双层半结晶结构。结晶的侧链抑制了主链的分子运动，因此除非ITA浓度足够高以致Tg>熔点（Tm），否则玻璃化转变温度（Tg）不会分解。共聚物的软化点和模量随ITA浓度的增加而增加，但热稳定性下降。;共聚物主链上的ITA部分被金属乙酸盐中和，生成Na-，Ca-和Zn-无规离聚物梳状架构。通常，离子基团的引入增加了Tg并抑制了侧链堆积的结晶度。具有高SM侧链密度的离聚物具有两个自组装纳米相分离的竞争驱动力：离子聚集和侧链晶体堆积。中和后，通过小角度X射线散射（SAXS）分析和透射电子显微镜（TEM）观察到从半结晶薄片到球形离子聚集体的形态转变。热力学分析表明，随着中和度的增加，抗穿透变形的能力增强，在Tg以上观察到明显的橡胶态平稳状态。玻璃器皿中PLA的受控酯交换反应是制备分子量受控的甲基丙烯酸酯官能化PLA大分子单体的有效方法。用于合成多种共聚物。该官能化的PLA大分子单体与ITA的共聚反应完全抑制了所研究PLA链长度范围内的侧链结晶度。对于足够高的中和水平，观察到Tg增加。该离聚物中离子聚集的动力学非常缓慢，但是在高温下退火有助于达到微观结构的平衡。

著录项

  • 作者

    Shang, Shurui.;

  • 作者单位

    University of Connecticut.;

  • 授予单位 University of Connecticut.;
  • 学科 Chemistry Polymer.;Engineering Materials Science.;Engineering Chemical.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 159 p.
  • 总页数 159
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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