【作者】 宋江选；

【导师】 梁兴泉； 刘平桂；

【作者基本信息】 广西大学 ， 应用化学， 2007， 硕士

【摘要】 利用-OH和-NCO的亲核加成反应，直接合成出端硅氧烷基聚己内酯/聚硅氧烷(PCL-TESi/PDMS-TESi)，利用合成出的PCL-TESi/PDMS-TESi对环氧树脂(EP)进行复合改性，通过溶胶．凝胶技术及胺类固化剂与环氧基的交联固化作用固化复合体系。利用电子扫描显微镜(SEM)、透射电镜(TEM)、能量色散显微分析(EDS)研究了复合体系的微观形貌。结果表明，PCL-TESi/PDMS-TESi的加入明显改善了复合体系的韧性。当复合体系中PCL-TESi/PDMS-TESi的含量较少时，即PCL-TESi/PDMS-TESi∶EP＜4∶6(wt/wt，下同)，复合体系呈现“海岛结构”，有机硅和聚己内酯形成的分散相分散在环氧树脂的连续相中，且分散相的颗粒随着PDMS-TESi/PDMS-TESi含量增高而变大。当复合体系中PCL-TESi/PDMS-TESi∶EP=4∶6时，PDMS-TESi/PDMS-TESi经水解缩合所形成的网络与环氧树脂的三维立体网络互相穿越，形成互穿网络结构(IPN)。当PCL-TESi/PDMS-TESi∶EP＞6∶4时，体系发生相反转，环氧树脂形成的“岛相”分散在PCL-TESi/PDMS-TESi形成的“海相”中。利用TGA和DTG考查了复合体系的耐热性能和热分解机理。结果发现，随着PCL-TESi/PDMS-TESi的加入量的增加，体系的初始分解温度(定义5％失重率下的分解温度为初始分解温度)与纯环氧树脂相比，先降低后增加然后再下降。当PCL-TESi/PDMS-TESi与EP以5∶5复合时，体系的初始分解温度最高，达到309.7℃，比纯环氧树脂的初始分解温度高出153.9℃。通过测试复合体系的接触角，进而利用Owens-Wendt-Kaelble模型计算出表面张力。复合体系的表面张力随PCL-TESi/PDMS-TESi的加入量的增加呈下降趋势，且室温固化体系要比50℃下固化的表面张力要小。同时利用XPS分析了试样的表面的元素分布情况，结果表明，Si元素在一定程度上在向表面迁移富集。研究了复合体系的耐腐蚀性能。结果表明，整体上改性后的复合体系的质量变化率S变化都不大，耐水、耐酸、耐盐性都较好。且随着PCL-TESi/PDMS-TESi含量的增大，耐水、耐酸、耐碱性能先变差，后变好。当PCL-TESi/PDMS-TESi∶EP=5∶5时，体系的耐水、耐酸、耐盐性能最好。复合体系在随着PCL-TESi的含量的增大体系的耐碱性能逐渐变差。本文所采用的实验方法和得到的一系列研究结果，为环氧树脂的改性提供了一些重要的参考数据和启示，有重要的研究意义。更多还原

【Abstract】 Silyl-terminated polyprolactone/polydimethysiloxane （PCL-TESi/PDMS-TESi） was directly synthesized via -OH and -NCO nucleophlic addition reaction.Epoxy resin （EP） was then modified with the PCL-TESi/PDMS-TESi oligomers.The modified system was cured with amino curing agent via amoni-glycidylreaction and Sol-gel process at different oligomer/epoxy ratio.The morphology of composites system was investigated by Scanningelectron microscopy （SEM）, Transmission electron microscopy（TEM）, andEnergy disperse spectroscopy（EDS）. The results showed that toughness of themodified epoxy resin was evidently improved when different content ofPCL-TESi/PDMS-TESi oligomer was added. The phase structure of themodified composite changed from separated phase, via co-continuous phase, tophase inversion with increasing PCL-TESi/PDMS-TESi content, where thephase formed by PCL-TESi and PDMS-TESi dispersed in continuous EP phase,when ratio of PCL-TESi/PDMS-TESi and EP was smaller than 4:6 （wt%）, andthe dimension of dispersed phase gradually increased with increasingPCL-TESi/PDMS-TESi content. Furthermore, when the ratio was between 4:6 and 6:4, phase structure changed to Inter-penetrating Network （IPN） via thehydrolysis, condensation of-Si（OR）₃ and amoni-glycidyl reaction.Thermal decomposition properties of the cured composites were studied byTGA and DTG, the results of which indicated that initial decompositiontemperature （defined as temperature at 5% weight loss） decreased at first andthen gradually increased with increasing PCL-TESi/PDMS-TESi content. Theinitial decomposition temperature was 309.7℃at PCL-TESi/PDMS-TESi:EP=5:5, higher 153.9℃than pure epoxy resin.The surface tension of composite system was obtained based on the contactangle via Owens-Wendt-Kaelble model. The results showed that the surfacetension decrease with the increasing of PCL-TESi/PDMS-TESi content.However, the composites cured at 50℃had a higher surface tension than thatcured at room temperature. At the same time, the distribution of Si element atthe composites surface was studied by X-ray photo spectroscopy, confirmingthat Si element migrated toward surface to some extent.Corrosion resistance properties of the composites were also studied. Theresults showed the composites had a little change of mass change generally,indicating that they had a good anti-corrosion performance. But water-resistance,acid-resistance and salt-resistance increased after decreasing a little with theincreasing of PCL-TESi/PDMS-TESi content and reached a peak atPCL-TESi/PDMS-TESi:EP=5:5. But the base-resistance properties graduallybecame worse with increasing PCL-TESi/PDMS-TESi content. All of research methods, experimental data and results in the paper arebenefit to modify epoxy resin in the future.更多还原