硅橡胶/正硅酸乙酯杂化膜的制备及其富氧性能

Synthesis and Oxygen-enriching Property of Silicone Rubber-TEOS Hybrid Membrane

以2,4,6,8-四甲基环四硅氧烷(D4H)和乙烯基三甲氧基硅烷(VTMO)为原料,通过硅氢加成反应合成了环状分子上含有硅氢原子和三甲氧基硅基的交联剂。使用这种交联剂,以摩尔分数为10%乙烯基硅橡胶(PDMS)和正硅酸乙酯(TEOS)为基质材料,制备了改性硅橡胶杂化膜材料。成膜过程包括3种交联反应:硅氢原子和乙烯基的加成反应、三甲氧基硅基和TEOS自身和相互之间的水解、缩合反应。透气性能测试表明,当TEOS质量分数为25.0%时,该膜具有良好的成膜性和富氧性能。在30℃和0.05 MPa压差下,PO2为3.7×107Pa,αO2/N2为3.45,这一富氧性能明显优于当前膜科学界对硅橡胶的改性目标:PO2>1.0×107Pa,αO2/N2>3.0。

A new crosslinking agent containing silicon-hydrogen atoms and trimethoxylsilicon groups was synthesized by controlling the molar ratio of 2,4,6,8-tetramethylcyclotetrasiloxane to vinyltrimethoxyl-siloxane to be 1：2. A PMDS hybrid membrane was also prepared by using the crosslinking agent, a silicone rubber containing vinyl groups of 10% （molar fraction） and tetraethoxysilicone（TEOS） were chosen as the matrix materials. There were three types of the crosslinking reactions involved in the membrane-forming process. These included an addition reaction between the silicon-hydrogen atom and the vinyl group, hydrolyzation and condensation between trimethoxylsiloxane and TEOS and their self hydrolyzation and condensation. The chemical structures and morphologies of the hybrid membranes were characterized by using FTIR and SEM. The mechanical properties were also measured. The hybrid membrane containing a mass fraction of 25.0% of TEOS showed a good membrane-forming property, better optimal mechanical performance and oxygenenriching property. For example, at 30 ℃ and 0.05 MPa, PO2 and αO2-N2 were 3.7 ×10^7 Pa Barrer and 3.45, respectively, which are higher than the target of modified silicone rubber membranes at present ： Po2 〉 1.0×10^7 Pa αO2/N2 〉 3. 0.