【作者】 席欢；

【导师】 何静；

【作者基本信息】 北京化工大学 ， 应用化学， 2005， 硕士

【摘要】 本文在微乳液中,通过调变微乳液组成制备层板剥离水滑石(LDH),并将其作为无机添加粒子制备层板剥离LDH/聚合物复合材料,研究其对聚合物基体热稳定性及机械性能的影响。 在烷烃/N-月桂酰基谷氨酸(LG)/水的O/W微乳液中,制备得到层板剥离水滑石和插层水滑石,并研究了微乳液中油相含量和烷烃链长对水滑石层板剥离程度的影响,同时对层板剥离水滑石进行了孔结构分析和形貌观测。研究表明,在微乳液中从无油相加入,到油相含量的逐渐增加,水滑石由插层结构向层板剥离结构过渡;微乳液中采用长链的烷烃有利于水滑石层板剥离的实现;与插层水滑石相比,层板剥离水滑石具有较大的孔容、比表面积和最可几孔径;高分辨电镜观察到层板剥离水滑石是纤维状。 将层板剥离水滑石作为无机添加粒子,采用原位聚合方法制备了LDH/PVAc、LDH/PS和LDH/PMMA复合材料,采用共混方法制备了LDH/PVAc和LDH/PP复合材料。研究发现,层板剥离水滑石在极性聚合物PVAc、PMMA基体中分散较为均匀,而在极性较弱的聚合物PS中分散相对不均匀。层板剥离水滑石的添加能够显著提高PVAc基体的热稳定性,对PMMA和PS基体的热稳定性略有提高。通过对LDH/PMMA复合材料的拉伸性能研究发现,添加层板剥离水滑石,能够提高PMMA基体的杨氏模量、最大拉伸强度和韧性,但并不能显著改善复合材料断裂伸长率;在无机添加量(2%)相同的情况下,碳酸根水滑石降低基体的最大拉伸强度、断裂伸长率和韧性,只对杨氏模量略有提高;插层水滑石对杨氏模量、最大拉伸强度和韧性的影响介于插层水滑石和碳酸根水滑石之间,对断裂伸长率的影响与层板剥离水滑石相当。在实验范围内,层板剥离水滑石提高PP基体的抗冲强度并存在最佳添加量,插层水滑石在少量添加情况下对PP基体的抗冲性能无明显影响,适宜的添加量提高基体抗冲性能,碳酸根水滑石的添加降低PP基体的抗冲强度。更多还原

【Abstract】 Polymer/inorganic nanocomposites attract scientists’ great interests because of their excellent properties than their counterparts. To solve the problem of the dispersion of the inorganic materials in the polymer matrix, we propose to prepare the solid delaminated layered double hydroxides (LDH) in a microemulsion, and disperse these inorganic materials into the polymer matrix to prepare a kind of nanocompostes.In my research, the delamination of layered double hydroxides (LDH) is achieved in a microemulsion composed of alkyl/ N-Lauroyl-glutamate/water. The diffraction peaks at low angle characteristic of LDH disappeared when the amount of alkyl reached a proper degree in the microemulsion, indicating that LDH layers might be delaminated. The delamination of LDH layers is proved by further carbonate-exchanged experiment. The delaminated LDH gives a larger pore volume, surface area and pore diameter than the intercalated counterpart.Subsequently, nanocomposites, which are based on PS, PVAc and PMMA polymers and use the delaminated layered double hydroxides as fillings are prepared by in-situ method and blending method. Nanocomposites exhibit improved thermal stabilities and mechanical properties than their counterparts.PP nanocomposites blended with LDH are also prepared by blending-method, nanocomposites with delaminated LDH exhibit better mechanical properties than the polymer matrixs.更多还原