Premium
Morphology of membranes formed by the isothermal precipitation of polyamide solutions from water/formic acid systems
Author(s) -
Shih ChienHsueh,
Gryte Carl C.,
Cheng LiaoPing
Publication year - 2005
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.21545
Subject(s) - nylon 6 , membrane , polyamide , formic acid , materials science , polymer chemistry , chemical engineering , crystallization , microporous material , isothermal process , nylon 66 , precipitation , copolymer , amorphous solid , polymer , chemistry , chromatography , composite material , organic chemistry , biochemistry , physics , meteorology , engineering , thermodynamics
Membranes were prepared by the direct and isothermal immersion of polyamide solutions in a formic acid/water bath. A crystalline polycaprolactam homopolymer, nylon 6, and a largely amorphous terpolymer of nylon 6, nylon 66, and nylon 610 were precipitated from solutions to form complex morphologies on the top and bottom surfaces and cross sections of the membranes. Terpolymer membranes exhibited the characteristics of a liquid–liquid phase‐separation process. According to the conditions of the solution and bath, nylon 6 precipitated to form membranes that showed dominance of crystallization or liquid–liquid phase separation. By precipitation from a solution containing a high concentration of a nonsolvent into a bath containing a high concentration of formic acid, skinless nylon 6 microporous membranes were formed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 944–960, 2005