Abstract Although series of latexes from plant oil-based acrylic monomers (POBMs) were recently synthesized in emulsion, two factors—allylic termination (the chain transfer reaction to the fatty acid double bonds) and the poor aqueous solubility of POBMs—lead to the lower total monomer conversion and molecular weight of the resulting latex polymers. In this study, amphiphilic oligosaccharide, methyl-β-cyclodextrin (M-β-CD), was used to improve the polymerizability of monomers from high oleic soybean (HO-SBM) and linseed (LSM) oil in copolymerization with styrene. Using X-ray diffractometry and differential scanning calorimetry, interactions between the monomers and M-β-CD were confirmed, while the formation of 1:1 complex from oligosaccharide and each monomer molecules was demonstrated by mass spectrometry. In the presence of “host-guest” complexes, polymer yield increases as the coagulum amount drops during the emulsion polymerization of both plant oil-based monomers with styrene indicating their enhanced aqueous solubility. Remarkably, latex polymers with a consistently higher molecular weight were obtained in the presence of M-β-CD. The complex formation and incorporation of monomer molecules into the oligosaccharide cavities protect the fatty acid moieties and diminishes chain transfer. The latter assumption was quantitatively confirmed in 1H NMR spectroscopy by determining the number of protons of the alkyl carbon−carbon double bonds (–CH = CH–) and the bisallylic hydrogen atoms (–CH = CH–CH2–CH = CH–) in the unsaturated fatty acid moieties of the latex copolymers. The observed effect is more pronounced for more unsaturated monomer from linseed oil. Based on the obtained results, M-β-CD plays a dual role in both enhancing POBM polymerizability as well as protecting against allylic termination chain transfer.

中文翻译：

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甲基-β-环糊精在具有各种不饱和度的高度疏水植物油基单体的乳液聚合中的双重作用

摘要 虽然最近在乳液中合成了一系列植物油基丙烯酸单体 (POBMs) 胶乳，但两个因素——烯丙基终止（脂肪酸双键的链转移反应）和 POBMs 的水溶性差——导致较低的所得胶乳聚合物的总单体转化率和分子量。在这项研究中，两亲性低聚糖甲基-β-环糊精 (M-β-CD) 用于提高高油酸大豆 (HO-SBM) 和亚麻籽 (LSM) 油中单体与苯乙烯共聚的聚合性。使用 X 射线衍射法和差示扫描量热法，证实了单体和 M-β-CD 之间的相互作用，而质谱法证明了寡糖和每个单体分子形成 1:1 的复合物。在“主客体”复合物的存在下，聚合物产率随着两种植物油基单体与苯乙烯的乳液聚合过程中凝结物量的下降而增加，表明它们的水溶性增强。值得注意的是，在 M-β-CD 的存在下获得了具有一致较高分子量的胶乳聚合物。单体分子复杂的形成和掺入低聚糖腔保护了脂肪酸部分并减少了链转移。通过确定烷基碳-碳双键（-CH = CH-）和双烯丙基氢原子（-CH = CH-CH2-CH = CH-）的质子数，在 1H NMR 光谱中定量证实了后一种假设。胶乳共聚物的不饱和脂肪酸部分。对于来自亚麻籽油的更多不饱和单体，观察到的效果更明显。基于所得结果，M-β-CD 在增强 POBM 聚合性和防止烯丙基终止链转移方面发挥双重作用。