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Preparation and structure of poly(vinyl alcohol)–poly(vinyl acetate) composite porous membrane
Author(s) -
Hayashi Sadao,
Hirai Toshihiro,
Hojo Nobumasa
Publication year - 1982
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.1982.070270518
Subject(s) - vinyl acetate , vinyl alcohol , materials science , polymer chemistry , membrane , solvent , emulsion polymerization , polymerization , chemical engineering , polyvinyl acetate , composite number , ammonium persulfate , chemistry , organic chemistry , composite material , polymer , copolymer , biochemistry , engineering
The preparation of poly(vinyl alcohol) (PVA)–poly(vinyl acetate) (PVAc) composite porous membrane was investigated by extracting PVAc with solvent from films of PVAc lattices which were obtained by the emulsion polymerization of vinyl acetate (VAc) in the presence of PVA. The formation of the porous membrane depended upon whether or not PVAc in the latex film was easily extracted with solvent. In the case of using hydrogen peroxide (HPO)–tartaric acid (TA) as an initiator, in the film of the latex which was produced from the batch method in which all ingredients of the batch were put into the reaction vessel before starting polymerization, PVAc could be extracted over 90% of total PVAc with common organic solvents. In the film of the latex which was produced from the dropwise addition method of VAc and initiator, the PVAc extraction was about 20‐30%. On the other hand, in the case of using ammonium persulfate as an initiator, the desired porous membrane was not obtained. The structure of the porous membrane obtained from the latex of the batch method by using HPO—TA consisted of spherical cells which were made up of PVA and grafted PVAc or insoluble PVAc like microgels, which were not extracted with organic solvent and were connected by small pores. The PVA—PVAc composite porous membrane is permeated by n ‐hexane with 5.58 × 10 2 mL/cm 2 ·s at 0.5 kg/cm 2 , by benzene with only 1.33 × 10 −3 mL/cm 2 ·s even at 60 kg/cm 2 .