【作者】 郭海波；

【导师】 蒲嘉陵； 王文广；

【作者基本信息】 北京印刷学院 ， 材料物理与化学， 2005， 硕士

【摘要】 本研究合成了p-乙烯基苯磺酸酯和乙烯基磺酸酯两大类聚合单体,分别带有甲基、异丙基、正丁基和环己基四种不同的保护基团,并将其与MMA和MAA共聚得到三元聚合物。这一类聚合物都可以在热的作用下发生分解反应产生磺酸基团,最终使树脂在热作用前后发生非常大的亲和性变化,从水不溶变成水溶。另外,这一类树脂也可以与一种以双酚A为母体的交联剂(BPA-DEVE)混合使用,可以使树脂的羧酸基团与交联剂的C=C双键基团在适当温度下预交联,形成三维网状结构的交联树脂体系。在热成像过程中,这种三维网状结构可以被热产生的磺酸分解,从而树脂在失去网状结构的同时,释放出大量的亲水基团(羧酸基团和磺酸基团),可以获得更大程度的亲和性变化。围绕这一目标,本研究对以下方面进行了全面系统的考察和研究。与交联剂兼容的共聚树脂体系。研究发现,交联剂在强酸(如共聚树脂不稳定产生的微量磺酸)存在下非常不稳定,发生反应而失去交联活性。本研究系统地考察了保护基团和磺酸酯单体的种类对树脂的热分解性能和热稳定性的影响。通过DSC、TG和IR数据可以看出,磺酸酯单体的保护基团的种类对树脂的分解温度和热稳定性有很大的影响,而磺酸酯单体的种类影响很小。含有甲基和正丁基的磺酸酯树脂的稳定性好,经80℃保温48小时后,自身的质量损失少,而且树脂结构没有明显的变化。实验发现乙烯基磺酸酯类单体活性较低,与MMA和MAA单体聚合时不能很好的参与聚合反应。以甲基为保护基团的磺酸酯树脂分解温度高,大于300℃,所以最终选择p-乙烯基苯磺酸正丁酯作为重点研究对象,系统地考察了其与其它两种单体形成的聚合物的热敏成像性能。(2) 共聚树脂的合成及热分解性能。本研究系统地研究了以p-乙烯基苯磺酸正丁酯、MMA和MAA为聚合单体的共聚反应的反应特征f1-F1曲线,树脂的结构和热分解性能。DSC数据显示,尽管树脂中磺酸基团的数量变化很大,但树脂的热分解顶点温度并没有明显的变化,保持在213℃左右。含有52 mol%浓度的磺酸酯基团和17 mol%浓度的羧酸基团的树脂烤版后可以迅速的溶解在中性水中,而当树脂中磺酸酯基团的含量小于或等于19%时,烤版后树脂不能溶解在中性水中。 <WP=3>(3) 对树脂溶解动力学评价。为了研究树脂溶解过程的动力学特征,本研究自行设计制作了一套可以实时跟踪薄膜溶解过程中膜层厚度变化的装置,并利用这套装置,对树脂和交联剂在预烤版过程中发生的交联反应和在烤版过程中发生的解交联反应以及不同树脂的溶解动力学特征进行了考察。(4) 树脂热敏成像的考察。通过在体系中加入对830nm激光存在有效吸收的红外染料,并通过830nm红外激光扫像以及相应的后处理,考察了所合成的树脂的热敏成像性能。研究结果表明,树脂体系经过曝光后,激光扫描过的地方会出现气孔和隆起,经显影后曝光区域的树脂会溶解消失,产生明显的凹槽。这一凹槽的深度与激光的能量和染料的加入量都有一定的关系。交联剂的加入可以改善预烤版后树脂膜的强度和表面的平滑度,使非曝光区域具有更强的耐水性,而曝光区域依然保持着较高的纯水溶解能力,这样就增大了曝光区域和非曝光区域的差异。更多还原

【Abstract】 Eight kinds of monomers based on monomer bases (i.e., p-styrenesulfonate and vinyl sulfonate) with four different protecting groups (i.e., methyl, isopropyl, butyl and cyclohexyl) were synthesized and copolymerized with methyl methacrylate (MMA) and methacrylic acid (MAA) to give tri-polymers containing sulfonate group, which undergone thermal decomposition and generated sulfonic acid, leading to a great change in affinity, say, from hydrophobic to hydrophilic, upon being heated. This kind of tri-polymers could also be used in combination with a bis-phenyl based cross-linker, i.e., 2,2-bis(4-(2-(vinyloxy)ethoxy)phenyl)propane (BPA-DEVE) and the carboxyl group of the polymer and the vinyl group of the cross-linker could undergo cross-linking reaction under suitable temperature, generating 3-dimension netlike structure. Upon imaging by thermal laser, this netlike structure could be decomposed by the thermo-produced sulphonic acid, releasing large amount of hydrophilic species (i.e., carbonic and sulphonic groups). An even greater gain would be, therefore, achieved in affinity change before and after imaging exposure. Aiming at this goal, a systematic investigation and study was carried out on following aspects. (1) Copolymer system that was compatible with cross-linker. Experimental result showed that the cross-linker was not stable with strong acid (e.g., even with the trace amount of sulphonic acid which would be generated by the copolymer decomposition because of poor thermal stability), undergoing self decomposition and losing activity of cross-linking. A systematic investigation was done on the effect of different protecting groups and sulfonate monomers on thermolysis and thermo-stability properties. DSC, TG and IR data revealed that decomposition temperature and thermal stability of the copolymer mainly relied on the type of protecting groups, almost regardless of the kind of sulfonate unit. Copolymers with protecting groups of methyl or butyl were thermo-stable, showing little lose of weight and no pronounced change in structure after having been kept at 80℃ for 48hrs. Vinyl sulfonate monomers were experimentally found of lower reactivity and couldn’t effectively copolymerize with MMA and MAA. Copolymers with methyl protecting group sulfonate unit had high decomposition temperature (more than 300℃) and the corresponding monomer (i.e., butyl p-styrenesulfonate) was, therefore, chosen as the main target for further study and its polymer formed with the other two <WP=5>different monomers was evaluated in thermal imaging.(2) Preparation and thermolysis of the copolymer. The reaction characteristic curve (i.e., f1-F1 curve), the structure and thermolysis property of the copolymer obtained by copolymerizing butyl p-styrenesulfonate, MMA and MAA were systemically studied. DSC data showed that thermo-decomposition temperature of the copolymer remained unchanged at about 213℃, in spite of a great change in the number of sulfonate unit. After baking, polymers containing 52 mol % sulfonate units and 17 mol % MAA units were highly soluble in neutral water, while those containing less than 19 mol % sulfonate units were insoluble in neutral water.(3) Study on dissolving dynamics of polymer film. In order to study dissolving dynamics of polymer film, a homemade appliance which can trace changes in film thickness during dissolution was designed and assembled. The appliance was used to characterize the cross-linking reaction which occurred between the polymer and cross-linker during pre-baking process, the de-cross-linking reaction during the baking process as well as dissolving dynamics of different polymer films. (4) Study on imaging performances of the polymer. Investigation was also done on thermal imaging performances of the polymers by 830nm laser scanning and post treatment. An IR dye which effectively absorbs at 830 nm was added to the polymer. Air-holes and protuberances were found in the laser scanned (exposed) areas and the polymer coating in the exposed areas were completely dissolved away, leaving b更多还原