Crystallinity and cross-linking in porous polymers synthesized from long side chain monomers through emulsion templating
Crystallinity and cross-linking in porous polymers synthesized from long side chain monomers through emulsion templating
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DOI：
10.1021/ma800195w
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发表时间：
2008-06-10
期刊：
影响因子：
5.5
通讯作者：
Silverstein, Michael S.
中科院分区：
文献类型：
--
作者：
Livshin, Shulamit;Silverstein, Michael S.
PolyHIPE 是一种交联的多孔聚合物，通过在高内相乳液 (HIPE) 的外相中聚合而合成。通过丙烯酸硬脂酯和二乙烯基苯(DVB)的共聚合成结晶polyHIPE聚合物。将在水/有机界面引发的聚合与等效本体聚合物、在有机相中引发的等效聚合以及包含等效非交联共聚单体（苯乙烯）的模型共聚物进行比较。两个主要熔融吸热中较高的一个与由富含丙烯酸硬脂酯的分子片段形成的更有序的晶体结构有关，这些分子片段优先通过在界面处引发而合成。交联限制了分子的流动性，将聚合物主链连接在一起并降低了峰值温度和结晶度。对于更多结晶的聚HIPE，模量随着DVB含量的增加而降低，反映了结晶度的主导效应。对于结晶度较低的 PolyHIPE，模量随着 DVB 含量的增加而增加，这反映了交联和聚合物主链刚度的主要影响。
A polyHIPE is a cross-linked, porous polymer synthesized through polymerization in the external phase of a high internal phase emulsion (HIPE). Crystalline polyHIPE polymers were synthesized through copolymerization of stearyl acrylate and divinylbenzene (DVB). Polymerizations initiated at the water/organic interface were compared to equivalent bulk polymers, to equivalent polymerizations initiated in the organic phase, and to model copolymers containing an equivalent non-cross-linking comonomer (styrene). The higher of the two main melting endotherms was related to a more ordered crystalline structure formed by stearyl acrylate-rich molecular segments that are preferentially synthesized by initiation at the interface. Cross-linking restricts molecular mobility, tying the polymer backbones together and reducing the peak temperatures and crystallinities. The decrease in modulus with increasing DVB content for the more crystalline polyHIPE reflects the dominant effect of crystallinity. The increase in modulus with increasing DVB content for the less crystalline polyHIPE reflects the dominant effects of cross-linking and polymer backbone stiffness.