以我国特有植物油大茴香脑为起始原料, 合成高性能聚合物的研究

Anethole, a naturally existing aromatic compound in China, has a very simple and interesting chemical structure, which is extracted abundantly from star anise, tarragon, fennel and basil. Thanks to its fragrance and high volatility, anethole has been widely used as a perfume in cosmetics, and a flavoring agent in foods and non-alcoholic beverages. This plant oil has been also used as a feedstock for the synthesis of some fine chemicals. Recently, the investigation on the application of anethole in polymeric materials has received much attention. However, most of the investigations employ complicated procedures for the synthesis of suitable monomers based on anethole. In this plan, we will design and synthesize 9 new monomers having both an anethole moiety and a benzocyclobutene, triazine and acrylate unit. We hope the monomers can be converted to the high performance materials used in electrical and microelectronic industry.

大茴香脑是一种我国特有的源于八角和茴香的植物油，主产地为广西，国外越南也有少量出产，每年全球产量约5000-7000吨。这种植物油的化学结构为对甲氧基苯丙烯，是理想的聚合物单体。但是，长期以来，它仅被用作香料和中成药添加剂，以及作为部分精细化学品的原料。鉴于大茴香脑转化为聚合物的研究较少，而它属于非食用植物油，开展其转化研究，无与人争食之忧。本课题组最近开发了三条转化大茴香脑为具有高耐热和低介电常数聚合物的方法，这些聚合物有望在极大规模集成电路和绝缘行业得到应用。为进一步研究大茴香脑向高性能材料的转化方法和转化产物的性能，本项目设计和合成九种基于大茴香脑的可直接热固化的新单体，它们含有苯并环丁烯、丙炔醚、三嗪环和丙烯酸酯等功能基团，研究这些单体的合成及固化产物的物理性能，筛选出耐热和绝缘性佳的品种，期望为电子和微电子工业提供高性能材料的新品种。特别是为我国的生物质转化提供新的方法。

本项目分别利用硫醇钠和五氟苯基硼两种方式脱去大茴香脑中甲氧基上的甲基，形成的酚和丙烯酰氯、苯并环丁烯和三嗪环偶联，生成的丙烯酸酯单体和苯并环丁烯大单体经过热固化，形成的交联网络显现出优异的性能；丙烯酸酯单体和丙烯酸甲酯共聚，获得了透明性和耐热性较佳的材料，可望替代传统的聚丙烯酸酯，也可作为聚碳酸酯的替代物；大茴香脑和苯并环丁烯偶联形成的大单体固化产物显现出较高的玻璃化转变温度，低的介电常数和低的吸水率。特别是大茴香脑引入十氟联苯后，所获得的苯醚和苯并环丁烯共聚，获得的聚合物在高频（10 GHz）下显现出优异的介电性能，有望在5G通讯中得到应用。