Thermal analysis of organically modified siloxane melting gels
Thermal analysis of organically modified siloxane melting gels
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DOI：
10.1007/s10973-011-2024-5
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发表时间：
2012-03-01
影响因子：
4.4
通讯作者：
Klein, Lisa C.
中科院分区：
文献类型：
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作者：
Jitianu, Andrei;Lammers, Kristin;Klein, Lisa C.
通过溶胶-凝胶法制备混合熔融凝胶，以单取代硅氧烷和二取代硅氧烷、甲基三甲氧基硅烷（MTES）与二甲基二甲氧基硅烷（DMDES）一起开始。制备浓度在50％MTES-50％DMDES和75％MTES-25％DMDES(以mol.％计)之间的五种凝胶组合物。随着单取代硅氧烷用量的减少，固结温度（熔融凝胶不再软化后的处理温度）从135℃升高至160℃。用差示扫描量热法记录的玻璃化转变温度随着单取代硅氧烷量的减少从-0.3℃降低至-56.7℃。当样品在固结温度下等温热处理2小时时，玻璃化转变温度增加了约15度，表明硅氧烷网络进一步交联。
Hybrid melting gels were prepared by a sol-gel process, starting with a mono-substituted siloxane and a disubstituted siloxane, methyltrimethoxysilane (MTES) together with dimethyldimethoxysilane (DMDES). Five gel compositions were prepared with concentrations between 50% MTES-50% DMDES and 75% MTES-25% DMDES (in mol.%). The consolidation temperature, the treatment temperature after which the melting gel no longer softens, increased from 135 to 160 degrees C with a decrease in the amount of the mono-substituted siloxane. The glass transition temperature, recorded with differential scanning calorimetry, decreased from -0.3 to -56.7 degrees C with a decrease in the amount of the mono-substituted siloxane. When a sample was heat treated isothermally for 2 h at the consolidation temperature, the glass transition temperature increased by about 15 degrees, indicating further crosslinking of the siloxane network.