Premium
Premembranes for porogen‐derived membranes and thermal decomposition of porogens
Author(s) -
Eyal A. M.,
Hazan B.,
Hajdu K.,
Edelstein D.
Publication year - 1992
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.1992.070450616
Subject(s) - differential scanning calorimetry , glass transition , thermal decomposition , polysulfone , polymer , polymer chemistry , solvent , membrane , materials science , casting , chemical engineering , decomposition , formic acid , chemistry , organic chemistry , composite material , biochemistry , physics , engineering , thermodynamics
Various t ‐butyl and di‐ t ‐butyl esters, N ‐boc and di‐ N ‐boc amines, metal salts of N ‐boc amino acid, and glycerol–formic acid esters are potential porogens for porogen‐derived membranes. Introduction of more than 20 such compounds into polysulfone or poly(vinyl chloride) films was studied. Transparency, IR spectra, changes in glass transition temperature, and differential scanning calorimetry were used to differentiate between molecular dispersion and formation of micro phases. The results show that for many of the studied additives more than 10% by weight can be practically molecularly dispersed in the polymers. The upper limit of porogen concentration in premembranes depends on characteristics of the polymer and of the porogen, on casting solvent composition, and on drying procedure. Metal salts of N ‐boc amino acids were found to be suitable heat‐decomposable porogens. Their decomposition in premembranes proceeds in two stages, in the first of which 2 C 4 H 8 + 2CO 2 are released per salt molecule. The metal complex formed goes through decarboxylation at a higher temperature. A heating procedure for completion of the first decomposition stage and for avoiding the second was determined.