Swelling behavior of the filling-type membrane

✍ Scribed by Takeo Yamaguchi; Shin-Ichi Nakao; Shoji Kimura

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 188 KB
• Volume: 35
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(199702)35:3<469::aid-polb6>3.0.co;2-n

✦ Synopsis

A model that can express the swelling of the filling-type membrane was developed by modifying a model that was developed for a crystalline polymer. The filling-type membrane is composed of two different polymers. One is porous substrate and another is a polymer that filled pores of the substrate. The filling technique can effectively suppress polymer swelling due to the substrate matrix. The model needs two parameters: one is a unit ratio of tie segments in the substrate to the filling polymer, f, which can express a mechanical strength of the substrate, and another is the Flory interaction parameter, x, between the filling polymer and a solvent that expresses a mixing energy. A porous high-density polyethylene film was used as a porous substrate, and plasmagraft filling polymerization technique could make the filling-type membrane. Methylacrylate was used as a grafting monomer that filled the pores of substrate. A swelling behavior of the filling-type membrane and pure poly(methylacrylate) were measured by the vapor sorption method at different solvent activities. The model was in good agreement with experimental results for the filling-type membrane. Using the model, swelling of the filling-type polymer was compared with a crosslinked polymer, which can be expressed by Flory and Rehner model. The comparison showed that the filling technique is a good way to suppress polymer swelling, and a high crosslinking density is needed to obtain the same level of swelling suppression effect the filling type membrane showed.