【作者】 刘文作夫；

【导师】 戴文利；

【作者基本信息】 湘潭大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 热塑性聚氨酯弹性体(TPU)具有良好的力学性能、耐磨性、耐油性等,通常作为一种韧性材料来改善其它材料的低温冲击性能。然而聚酯型TPU的耐水解与老化性差,限制了其应用范围。本文采用了耐水解助剂聚碳化二亚胺(PCD),环氧类化合物(苯基缩水甘油醚(PGE),环氧树脂(E51),3―(2,3-环氧丙氧)丙基三甲氧基硅烷(KH560)),马来酸酐接枝苯乙烯-乙烯/丁烯-苯乙烯嵌段共聚物(SEBS-g-MAH),填料(碳酸钙,硫酸钡)对TPU的力学性能,耐水解与老化性,加工性,热性能等进行了研究。1.研究了PCD和SEBS-g-MAH对TPU的力学性能,耐水解与老化性,热性能的影响。结果表明:加入PCD提高了体系的拉伸强度,断裂伸长率,在25℃空气或80℃水中的力学性能保持率,热稳定性,降低了吸水率和熔融流动速率;当PCD含量为3%时,体系的耐水解与老化性最佳。SEBS-g-MAH的加入,提高了TPU的拉伸强度,断裂伸长率,在25℃空气或80℃水中的力学性能保持率,降低了TPU的熔融流动速率,吸水率,热稳定性;当SEBS-g-MAH的质量分数为15%时,体系的耐水解与老化性最佳。FTIR分析测试结果表明,PCD,SEBS-g-MAH均可能与TPU存在一定氢键作用;同时PCD,SEBS-g-MAH的特征基团已接枝到TPU分子主链上。DSC测试结果表明,PCD,SEBS-g-MAH均与TPU之间存在一定的相容性。2.考察了环氧化合物(PGE,KH560,E51)对TPU的力学性能,耐水解与老化性,热性能的影响。加入KH560提高了体系的拉伸强度,断裂伸长率,在25℃空气或80℃水中的力学保持率,降低了体系的吸水率,熔融指数;加入E51或者PGE均降低了TPU的拉伸强度,断裂伸长率,在25℃空气或80℃水中的吸水率以及熔融指数,但提高了TPU在25℃空气或80℃水中的力学性能保持率。DSC测试结果表明,三种环氧化合物均与TPU存在一定的相容性。FTIR分析测试结果表明,三种环氧化合物的特征基团均已接枝到TPU主链上,且与TPU之间存在一定氢键作用。TGA测试结果表明,加入PGE,KH560以及E51等三者均使TPU的热稳定性下降。3.研究了填料(碳酸钙,硫酸钡)对TPU的力学性能,耐水解与老化性,热性能等影响。结果表明,加入硫酸钡,TPU的力学性能,在25℃空气中或80℃恒温水浴中的力学性能保持率均先增大后减小,吸水率以及熔融流动速率降低。碳酸钙的加入,TPU的拉伸强度,断裂伸长率先增大后减小,吸水率以及熔融流动速率降低,无论TPU放置于25℃空气中还是浸入80℃的恒温水浴中,加入5%~20%碳酸钙均可提高其耐水解与老化性。当碳酸钙质量分数为20%时,其耐水解与老化性达到最佳,然而体系的力学性能却略有降低。TGA测试结果表明,加入硫酸钡或碳酸钙使TPU热稳定性略有下降。4.考察了不同水解稳定助剂对TPU的平衡扭矩的影响。结果表明,加入PCD使TPU的加工性能变差,环氧类化合物,SEBS-g-MAH以及填料的加入则改善了TPU的加工性能。更多还原

【Abstract】 Thermoplastic polyurethane （TPU） elastomer has excellent mechanical properties, high abrasion resistance, anti-oil properties etc, which is widely used as a toughing material to improve toughness. However, polyester-based TPU is easily hydrolytic, which limits the application, and there’s few reseach work about how to improve TPU’s hydrolysis-aging resistance. In this paper, the effects of PCD, epoxy compounds （glycidyl phenyl ether （PGE）, 3-（2, 3-Epoxypropoxy） propyltrimethoxy- silane （KH560） and epoxy （E51））, SEBS-g-MAH, inorganic filler （CaCO3, BaSO4） on the hydrolysis-aging resistance, mechanical properties, processing properties, thermo- stability of TPU are inverstigated.Firstly, the influence of PCD and SEBS-g-MAH on mechanical properties, hydrolysis-aging stablity and thermostabity of TPU were studied. The results showed: adding PCD to TPU, the maintenance of mechanical properties in 25℃air or 80℃water, tensile strength and elongation at break of TPU were increased, while water absorptivity in 25℃air or 80℃water and the melt flow index were decreased. When the content of PCD was 3%wt, the hydrolysis-aging resistance of TPU became the best. For the TPU/SEBS-MAH blends, as the amount of MAH-SEBS increased, the tensile strength, elongation at break and maintenance of mechanical properties in 25℃air or 80℃water were increased, while the melt flow index and water absorptivity in 25℃air or 80℃water were decreased. When the content of SEBS-MAH reached 15%wt, the hydrolysis-aging resistance of the TPU became the best. The FTIR analysis revealed that the characteristic groups of the PCD and SEBS-g-MAH have grafted on the TPU backbone chain, separately. The DSC analysis showed there were exisisting some compatibity between the TPU and PCD or SEBS-g-MAH and TPU. The TGA results indicated that the addition of PCD increased the thermo stablity of TPU while SEBS-g-MAH made it worse.Secondly, the effects of glycidyl phenyl ether （PGE）, 3-（2, 3-Epoxypropoxy） propyltrimethoxysilane （KH560） and epoxy （E51） on the hydrolysis-aging resistance, mechanical properties, thermostabity of the TPU were investigated. The results showed: adding KH560 to TPU, the tensile strength, elongation at break, and the maintenance of mechanical properties in 25℃air or 80℃water were increased, while water absorptivity in 25℃air or 80℃water and the melt flow index of TPU were decreased. Adding PGE or E51 to TPU, the tensile strength, elongation at break, water absorptivity in 80℃water or in 25℃air and the melt flow index of TPU were decreased, while the maintenance of mechanical properties in 25℃air or 80℃water increased. The DSC analysis indicated that there was exsisting some compatibility between TPU and these there epoxy compounds. The FTIR analysis showed the characteristic groups of there epoxy compounds had grafted on the TPU backbone chain respectively, moreover there might be exsisting hydrogen bond between the epoxy compounds and TPU. The TGA analysis indicated that all of them decreased the thermo stability of TPU.Thirdly, the effects of BaSO₄, CaCO₃ on mechanical properties, hydrolysis -aging resistance and thermostabity of TPU were studied. The results revealed that adding BaSO₄ to TPU, the mechanical properties and maintenance of mechanical properties in 25℃air or 80℃water showed a trend from ascent to descent, while water absorptivity in 25℃air or 80℃water and melt flow index were decreased. Adding CaCO₃ to TPU, the mechanical properties were firstly increased then decreased, water absorptivity in 25℃air or 80℃water and melt flow index were decreased, maintenance of mechanical properties in 25℃air or 80℃water were increased. When the content of CaCO₃ achieved 20%wt, the hydrolysis-aging resistance got the best effect, while the mechanical properties were decreased compared with pure TPU. The TGA results indicated that adding BaSO₄ or CaCO₃ both decreased the thermo-stability of TPU.Fourthly, the effects of different hydrolysis resistance agents on the balance torque of TPU were investigated. The results showed that the processing properties of TPU were decreased by PCD while improved in the presence of SEBS-g-MAH, epoxy compouds and inorganical filler.更多还原