Abstract

Limonene is the major component of the essential oil from orange peel, with potential for polymeric production. However, due to some monomer’s structural characteristics its polymerization has low yield, needing new approaches to make the process more attractive. In this paper, limonene photochemical radical polymerization at low temperature was first studied using a combination of type II photo initiators and alkyl halide initiators. Low dispersity polymers (Ð < 1.21) were obtained in all polymerizations. The use of 2,2,2-tribromoethanol initiator allowed to obtain higher molar mass and monomer conversion. The polymer FTIR analysis confirmed the presence of the hydroxyl group from alkyl halide. Thermal analysis (DSC and TGA) of the material indicated a T_g of approximately 10 °C, and the degradation of the material achieved a maximum rate in 325 °C, indicating good thermal stability. The obtained polymer was soft, gum-like and very malleable, making it a possible candidate of renewable additive in coatings and adhesives.

Graphic Abstract

中文翻译：

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光诱导受控自由基聚合法合成聚柠檬烯

摘要

柠檬烯是橙皮香精油的主要成分，具有聚合物生产的潜力。然而，由于某些单体的结构特征，其聚合反应产率低，需要新的方法来使该方法更具吸引力。本文首先研究了Ⅱ型光引发剂和烷基卤化物引发剂在低温下的柠檬烯光化学自由基聚合。在所有聚合中均获得了低分散性聚合物（η<1.21）。使用2,2,2-三溴乙醇引发剂可获得更高的摩尔质量和单体转化率。聚合物FTIR分析证实来自烷基卤的羟基的存在。材料的热分析（DSC和TGA）表明T _g在大约10°C的温度下，材料的降解达到了325°C的最大速率，表明具有良好的热稳定性。所获得的聚合物是柔软的，胶状的且非常易延展的，使其成为涂料和粘合剂中可再生添加剂的候选者。

图形摘要