【摘要】 为进一步拓展桐油在高分子材料中的应用,制备了聚桐油基甲基丙烯酸酯类单体1（TMA₁）,并通过狄尔斯-阿尔德（Diels-Alder）反应制备单体2（TMA₂）,研究了桐油基单体自由基聚合的特性及与其他乙烯基单体共聚的特性,制备了一系列热塑性桐油基高分子。采用傅里叶红外光谱和核磁共振氢谱确定了化学结构,通过凝胶渗透色谱确定了桐油基高分子的分子量,采用热重分析仪和差示扫描量热仪分析了共聚单体及含量对热力学性能的影响,并进行了力学性能测试。结果表明:桐油基单体TMA₁不能进行自由基聚合,而经过Diels-Alder反应消除共轭双键的桐油单体TMA₂可以进行自由基聚合。所制备热塑性聚桐油基甲基丙烯酸酯（PTMA）的相对分子质量为15 500,多分散度为2.8,证明TMA₂单体自由基聚合顺利进行。通过与苯乙烯、甲基丙烯酸降冰片烯酯、丙烯酸丁酯共聚,实现对桐油基高分子的玻璃化转变温度及力学性能的调控。以苯乙烯为例,随着苯乙烯投料的增加,材料的玻璃化转变温度和机械强度增加。由此可以说明,热塑性聚桐油基甲基丙烯酸酯类高分子能够被高效合成且具有广阔的应用前景。更多还原

【Abstract】 Tung oil is a kind of woody oil with rich source, low cost, high reactivity and application value in China. However, the free radical polymerization of Tung oil is hard in terms of reaction mechanism. Tung oil has many conjugated double bonds, which are easily oxidized in air because of a cross-linking network, limiting the application of polymers. This article reported the preparation of thermoplastic polymers by free radical polymerization using Tung oil as a raw material. Firstly, a methacrylate monomer（TMA₁） was synthesized using a two-step method of amidation and esterification. Using the diene properties of the three conjugated double bonds on the Tung oil fatty acid chain, TMA₁ and maleic anhydride undergo Diels-Alder reaction to prepare a modified monomer（TMA₂）. Then, a series of thermoplastic Tung oil-based polymers was prepared by the free radical polymerization and copolymerization with other vinyl monomers, such as styrene, sobornyl methacrylate and n-butyl acrylate. The chemical structure was examined by the Fourier transform infrared（FT-IR） and nuclear magnetic resonance（¹H NMR）. The molecular weight of the polymer was characterized by the gel permeation chromatography（GPC）. Thermogravimetric analysis（TGA）, differential scanning calorimetry（DSC） and mechanical testing were used to study the thermal and mechanical properties of the polymer. The results showed that the TMA₂ can undergo free radical polymerization, because the conjugated double bond was eliminated by the Diels-Alder reaction, while the TMA₁ cannot. The Tung oil-based methacrylate（PTMA） showed the relative molecular mass of 15 500 and dispersity index of 2.8, indicating that the free radical polymerization of TMA₂ monomer proceeded smoothly. The glass transition temperature and mechanical properties of the polymer can be adjusted by introducing benzene ring, norbornene ring or aliphatic side groups. Taking benzene ring as an example, the glass transition temperature of copolymer increased with the increase of styrene content, which was because the rigid styrene groups further hindered the movement of polymer chains. At the same time, with the increase of styrene content, the mechanical strength and Young’s modulus increased significantly. The rich anhydride group in the thermoplastic polymer side chain of Tung oil provided an important basis for its application in biomass materials. In general, the thermoplastic Tung oil-based polymethacrylate polymers have good application potential in the design of materials in the future, which provides a possibility for preparing thermoplastic polymers with regular structure and functional polymers with special purposes. Researchers can use Tung oil-based thermoplastic polymers to develop elastomers, nanocomposites, shape memory materials, and epoxy resin, as well as apply for other high-performance and functional materials.更多还原