文档介绍：武汉理工大学硕士学位论文论文摘要本文选用玻璃化转变温度极低、韧性俱佳的聚氨酯A、B组分原料,加入环氧树脂中,制备出EP/PU改性材料,通过FFIR表征其结构与反应机理。选用不同的固化体系,以选择最佳固化体系。利用SEM观察其微观形貌, 和DMA曲线研究其耐热性能和阻尼性能。红外光谱显示,四种固化体系下,聚氨酯A、B组分都能与环氧树脂充分交联,完全固化,二者相容性较好。通过SEM分析微观形貌与力学性能的关系, 发现纯环氧树脂发生明显的脆性断裂,而改性后的EP/PU改性材料则发生的是韧性断裂,主要归功于聚氨酯中的“软段”增加了整个体系的柔韧性。曲线则表明,与纯环氧树脂相比,加入Pu后,材料的热分解机理并没有改变, 其分解峰稍有上升,耐热稳定性略有提高。本文讨论了不同固化体系下材料力学性能和阻尼性能的差异,并分析了聚氨酯PU含量对改性材料综合性能的影响。结果表明,固化体系对材料的性能影响显著,以增韧和不牺牲强度为目的,对比发现,所选固化剂中,T-403体系综合性能最佳。选用T-403固化剂时,与纯环氧树脂相比,EP/PU改性材料的韧性显著提高,,%,断裂伸长率也明显增大, 拉伸强度和弯曲强度略有降低;而且材料的玻璃化转变温度降低, 的阻尼温域拓宽。PU含量对EP/PU改性材料力学性能和阻尼性能有很大影响: 随着PU含量的增加,材料的冲击强度和断裂伸长率增大,韧性提高,拉伸强度和弯曲强度略有下降;玻璃化转变温度Tg降低,损耗因子tand增大,阻尼温域加宽。当PU含量为15%时,EP/。C, ;当PU含量为10%时,材料的阻尼温域最宽。由此可见,改性材料的阻尼性能得到改善,冲击强度增加,韧性增强,其他力学强度下降甚微,仍能满足各种需求。关键词:EP/PU改性材料,增韧,力学性能,耐热性能,阻尼性能武汉理工大学硕士学位论文论文 Abstract EP/PU modified materialwas prepared byusing ponent A and Bwithlowglass-transition temperature and good toughness asraw materials toadd into印oxy resin,and itsstructure and reactionmechanism were characterized bV Fr- different kinds ofcuring agents and discussed theinfluence ofcuring agent onmechanicalproperties by mechanics performance was used to observe itsmicrocosmic feature anditsheat—resistantproperty and damping property were studied by andDMA curves. IRanalysis showed that ponent A and B wcrc able to crOSS-linked absolutely with epoxy resins,patibility was quite relationship ofmicrocosmic featureand mechanical properties wcre studied bvSEM. Itcould befound thatepoxy resins had obvious brittlefracture butEP沿U modified material happened ductile fracture mainly due to the‘‘flexible segment’’of polyurethane increase the entireflexibility ofEP curves showed pared with pure epoxy resins,thermal position mechanism ofmodified material did notchange,its position peak had increased slightly,heat—stability alsohadslightly increased. The difference ofmechanical properties anddamping