The influence of molecular weight of siloxane macromere on phase separation morphology, oxygen permeability, and mechanical properties in multicomponent silicone hydrogels

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• 作者：Huiwen Tao ; Xueqin Zhang ; Ying Sun ; Hong Yang ; Baoping Lin
• 关键词：Silicone hydrogels ; Siloxane macromonomer ; Oxygen permeability ; Mechanical properties ; Phase separation morphology
• 刊名：Colloid and Polymer Science
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：295
• 期：1
• 页码：205-213
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Polymer Sciences; Soft and Granular Matter, Complex Fluids and Microfluidics; Characterization and Evaluation of Materials; Physical Chemistry; Food Science; Nanotechnology and Microengineering;
• 出版者：Springer Berlin Heidelberg
• ISSN：1435-1536
• 卷排序：295

文摘

To clarify the influence of molecular weight of siloxane macromonomer on phase separation morphology, oxygen permeability, and mechanical properties, silicone hydrogels were prepared by copolymerizing mixtures of methacrylate-terminated siloxane macromonomer (MTSM), silicon-containing monomers tris(trimethylsiloxy)-3-methacryloxpropylsilane, and three hydrophilic monomers N,N-dimethylacrylamide, N-vinylpyrrolidone, and hydroxypropyl methacrylate. The number of Si–O–Si repeating units was equal in every silicone hydrogel while the molecular weight of MTSM ranged from 1000 to 10000 g/mol. The oxygen permeability coefficient (Dk), equilibrium water content (EWC), light transmittance, mechanical properties, and internal morphologies of obtained silicone hydrogels were characterized, and their relationships were discussed in detail. The results showed that the Dk value increased first and then decreased with the chain length of MTSM increasing. The EWC presented an increasing trend and the light transmittance decreased with the increase of MTSM chain length. The elongation increased while the modulus and the tensile strengths of the silicone hydrogels decreased along with the MTSM molecular weight increasing. The internal morphologies of the silicone hydrogels were observed by transmission electron microscope. The results indicated that the silicone hydrogels presented different phase separation structures depending on the molecular chain length of MTSM. The continuous silicone phase formed and made significant contributions to high Dk value as the molecular chain length of MTSM was moderate. Besides, a model was proposed to explain the effect mechanism of the MTSM chain length on the oxygen permeability and the EWC. This work provided a facile method to preparing the silicone hydrogel materials with desirable water absorption and high oxygen permeability by adjusting the molecular weight of macromonomers.