【作者】 姚丽；

【导师】 吕志平；

【作者基本信息】 太原理工大学 ， 物理化学， 2007， 硕士

【摘要】 聚氨酯弹性体具有许多优良特性，如高弹性，耐磨性，耐油性，耐臭氧性，耐低温性，高粘接性，有良好的机械强度以及好的电绝缘性等，因而被广泛应用于国民经济的各个领域，成为不可缺少的重要材料之一。在许多场合往往对耐撕裂强度或拉伸强度之间某一性能要求更高，为了得到交联方式、交联密度与拉伸性能或耐撕裂性能之间的关联性，本文首次设计了一种多交联体系聚氨酯材料，多交联体系是指材料中不同交联密度的微区或链束相互穿插呈高分子合金结构。在此基础上进一步考察了多交联体系聚氨酯／分子筛复合材料的性能。本文以聚酯多元醇(PEA)、甲苯二异氰酸酯(TDI)、3，3′-二氯-4，4′-二氨基二苯甲烷(MOCA)及4A、13X分子筛为主要原料，采用预聚法制备了多交联体系聚氨酯材料及聚氨酯／分子筛复合材料，对其力学性能、耐溶剂性能进行了测试，并利用DSC、DMA、SEM等手段对其进行了表征。力学性能测试结果表明：在预聚体的-NCO含量为4.5％的设计配方下，与相同配料均一体系聚氨酯材料相比，多交联体系聚氨酯材料的耐撕裂性能有显著提高，拉伸性能稍有下降，但下降幅度不大，扯断伸长率变化不大。平均扩链系数在0.9左右时，多交联体系聚氨酯材料的耐撕裂强度和拉伸强度比较均衡。在预聚体的-NCO含量为4.5％，分子筛含量为7％的设计配方下，与相同配料均一体系的聚氨酯／分子筛复合材料相比，多交联体系聚氨酯／分子筛复合材料的耐撕裂性能有明显地提高，拉伸性能下降不大，扯断伸长率变化不大。耐溶剂性能测试说明：与均一体系聚氨酯材料相比，多交联体系聚氨酯材料的耐溶剂性能明显提高；与多交联体系聚氨酯材料相比，多交联体系聚氨酯／分子筛复合材料的耐溶剂性能有显著提高。DMA测试结果显示：多交联体系聚氨酯材料的储能模量和耗能模量明显增加，阻尼性能下降；玻璃化转变温度降低，微相分离更好。分子筛加入到聚氨酯体系中，作为异相成核剂影响了聚氨酯软硬链段之间的微相分离，使得微相分离更好，阻尼进一步下降。DSC结果表明：多交联体系聚氨酯材料在210℃左右的结晶熔融峰明显大于均一体系聚氨酯材料在此温度附近的熔融峰，表明部分交联密度小的区域硬链段的结晶更规整，晶片也相应的大，结晶度增大，影响了微相分离；对于多交联体系聚氨酯／分子筛复合材料，分子筛的加入影响了微相分离。SEM测试结果显示：13X、4A分子筛在聚氨酯中的分散基本均匀，说明分子筛在本研究体系下具有良好的分散性。综合上述结果，多交联体系聚氨酯材料存在不同交联密度的微区域，部分交联密度小的区域硬链段线性好，使得材料有更好的耐撕裂性能，微相分离更好，阻尼下降；部分处于材料表层的交联密度大的链束或胶团能提高材料的致密性，使得材料具有较好的耐溶剂性能。更多还原

【Abstract】 Polyurethane elastomer （PU） has good elasticity, wearable property, good oil resistance, the ozone（O₃） resistance, microtherm resistance, well viscidity, good mechanical property and electrical resistance and so on. So it has been widely applied in the every area of civil affairs. One of higher mechanical properties is needed for PU elastomer on some occasions, tear resistance or tensile strength. To obtain relationship between crosslink density and tensile strength or tear resistance, we design polyurethane with different crosslink density micro-domains, and the micro-domains form polymer alloy structure. On the other hand, PU/zeolite composites with different crosslink density micro-domains were studied.The prepolymerization method was used to prepare PU with different crosslink density micro-domains and PU/zeolite composites with different crosslink density micro-domains with PEA, TDI, MOCA and zeolite 13X or 4A. The PU materials were characterized by mechanical properties measurement, solvent resistance measurement, DSC, DMA and SEM.The test results of mechanical properties show that when the content of -NCO group in prepolymer is 4.5%, tear resistance strength of PU with different crosslink density micro-domains are increased, tensile strength are decreased and elongation at break are unaltered, compared with homogeneous PU materials. Moreover, tensile strength and tear resistance of PU with different crosslink density micro-domains at the average crosslink coefficient 0.9 are optimum.When the content of -NCO group in prepolymer is 4.5%, PU/zeolite composites with 7% zeolite contented, with different crosslink density micro-domains exhibit higher mechanical properties than homogeneous PU/zeolite composites.The solvent resistance property test reveals that PU with different crosslink density micro-domains has better solvent resistance property. Compared with homogeneous PU/zeolite composites, solvent resistance property of PU/zeolite composites with different crosslink density micro-domains is improved obviously.The DMA results indicate that the storage modulus and the loss modulus of PU with different crosslink density micro-domains both increase, the glass transition temperature（Tg） and the damp modulus both decrease, the microphase separation improve. Besides, the adding of zeolite improves the microphase separation of soft and hard segments.The DSC results verify that crysterization of hard segment of PU with different crosslink density micro-domains increase at 210℃. The filling of zeolite affects on the microphase separation, the crystal type of hard segment of PU/zeolite composites with different crosslink density micro-domains changes.The SEM photographs reveal that the particles of zeolite are dispersed homogeneously in composites.Consequently, PU with different crosslink density micro-domains possess higher tear resistance strength, lower glass transition temperature and damp modulus, better microphase separation. On the other hand, the materials exhibit better solvent resistance property due to the chains with high crosslink density.更多还原