脱水蓖麻油/马来酸酐加合物的制备工艺优化及其在压敏胶中的应用

Optimization of preparation process of dehydrated castor oil/maleic anhydride adduct and its application in pressure sensitive adhesive

以脱水蓖麻油和马来酸酐为原料,酸价为评价指标,通过研究马来酸酐与脱水蓖麻油底物比(物质的量之比)、反应温度、反应时间因素对狄尔斯-阿尔德(Diels-Alder)反应加合程度的影响,优化脱水蓖麻油/马来酸酐加合物的最佳制备工艺。研究结果表明:(1)底物比、反应温度和反应时间均对脱水蓖麻油/马来酸酐加合物的加合程度有显著影响,且影响因素排列次序为:反应温度>底物比>反应时间。较佳制备工艺为:底物比为12∶10,反应温度为120℃,反应时间为3.0 h。此时,加合物的性能较佳,加合物的酸价可达60.9 mg KOH/g。(2)脱水蓖麻油和马来酸酐有效地发生了DA反应,且以一分子脱水蓖麻油和一分子马来酸酐反应形成的加合物为主。(3)脱水蓖麻油/马来酸酐加合物的流动性和热稳定性较好,马来酸酐的引入提高了其玻璃化转变温度。(4)马来酸酐的引入赋予脱水蓖麻油较多的极性官能团,因此在与环氧大豆油共聚时,强化了压敏胶的剥离强度和初粘力。与环氧大豆油基压敏胶相比,脱水蓖麻油/马来酸酐加合物与环氧大豆油共聚制备的压敏胶的剥离强度提高了约2倍,初粘力提高了约10倍。

Using dehydrated castor oil and maleic anhydride as raw materials,with acid value as the evaluation index,the optimal preparation process of dehydrated castor oil/maleic anhydride adduct was optimized by studying the effects of substrate ratio(molar ratio)of maleic anhydride to dehydrated castor oil,reaction temperature,and reaction time on the degree of Diels-Alder reaction addition.The research results showed that,(1)The substrate ratio,reaction temperature,and reaction time all had a significant impact on the degree of addition of dehydrated castor oil/maleic anhydride adduct,and the order of influencing factors was:reaction temperature>substrate ratio>reaction time.The optimal preparation process was:the substrate ratio of 12∶10,reaction temperature of 120℃,and reaction time of 3.0 h.At this point,the performance of the adduct was optimal,and the acid value of the adduct could reach 60.9 mg KOH/g(.2)Dehydrated castor oil and maleic anhydride effectively underwent DA reaction,and the adduct formed by the reaction of one molecule of dehydrated castor oil and one molecule of maleic anhydride was the main one.(3)Dehydrated castor oil/maleic anhydride adduct had good fluidity and thermal stability,and the introduction of maleic anhydride increased its glass transition temperature(.4)The introduction of maleic anhydride endowed dehydrated castor oil with more polar functional groups,thus enhancing the peel strength and tack of pressure sensitive adhesive when copolymerized with epoxy soybean oil.Compared with epoxy soybean oil-based pressure sensitive adhesive,the peel strength of pressure sensitive adhesive prepared by copolymerizing dehydrated castor oil/maleic anhydride adduct with epoxy soybean oil was increased by about 2 times,and the tack was increased by about 10 times.