Premium
A novel method to prepare microcellular poly(vinyl alcohol) foam based on thermal processing and supercritical fluid
Author(s) -
Liu Pengju,
Chen Wenhua,
Jia Yingbin,
Bai Shibing
Publication year - 2017
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.3885
Subject(s) - vinyl alcohol , materials science , supercritical fluid , saturation (graph theory) , chemical engineering , plasticizer , solubility , intermolecular force , porosity , drop (telecommunication) , supercritical carbon dioxide , composite material , organic chemistry , polymer , molecule , chemistry , mathematics , combinatorics , engineering , telecommunications , computer science
Combining the thermal processing and supercritical fluid technology develops a novel preparation method of microcellular poly(vinyl alcohol) (PVA). Water, as the plasticizer in system, can form the hydrogen bonding with pendant hydroxyl of PVA and weaken its strong intermolecular and intramolecular forces to realize the thermal processing. Supercritical carbon dioxide (sc‐CO 2 ) can easily dissolve into water‐plasticized PVA (WPVA) because of the destruction of crystal region caused by water, and the enhanced sc‐CO 2 solubility can greatly improve the foamability of WPVA. The porous structure generates through the saturation of sc‐CO 2 in WPVA sample and followed by pressure drop‐induced phase separation. The foaming behavior of WPVA was studied as a function of saturation pressure, foaming temperature, and saturation time. The cell density, cell size, and distribution of the obtained foam can be controlled by tuning processing conditions. The results revealed that the cell size decreased, and its distribution narrowed with saturation pressure increasing, or decrease of foaming temperature. But excessively increasing the saturation time generated a negative effect on the foaming behavior owing to the deteriorated plasticization effect resulted from the loss of water. Copyright © 2016 John Wiley & Sons, Ltd.