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Structure formation and dynamic properties of physical gels produced with thermoplastic elastomer and monomer
Author(s) -
Fukahori Yoshihide,
Mashita Naruhiko
Publication year - 2000
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 - 10.1002/1099-1581(200008/12)11:8/12<472::aid-pat994>3.0.co;2-r
Subject(s) - monomer , materials science , polymer , elastomer , nucleation , chemical engineering , thermoplastic polyurethane , phase (matter) , thermoplastic elastomer , polymer chemistry , miscibility , composite material , copolymer , organic chemistry , chemistry , engineering
We propose new non‐aqueous polymer physical gels prepared with a small amount of semi‐crystalline thermoplastic elastomers (nearly 10% concentration) and a large amount of monomers of low molecular weight. The gels have a three‐dimensional continuous polymer network whose unit structure, a spherical cell of a few tens micrometer is mutually connected with holes, i.e. the tunnels. The structure formation initiated as spinodal decomposition but the mechanism changes into the nucleation and growth in an early stage of progression. Droplets of monomer‐rich phase are discharged from the homogeneous polymer‐rich phase. For operating such a mechanism in the system, it is of importance to be the big difference between the mobility of polymer and monomer. In particular, the molecular weight of the monomer to be less than a few thousands is an essential factor. The super‐structure thus formed can be fixed and stabilized only when the system is cooled down below its melting temperature in the semi‐crystalline polymer and monomer system. In the non‐crystalline polymer and monomer system, although the super‐structure is also formed and increases in size, the structure finally collapses and becomes droplets which disperse in the monomer‐rich matrix during the cooling process. The physical gels are quite stable thermally and dynamically and give the feel of gelatin, flesh and others depending on species of polymer and oil and their composition. The gels are now applied to industrial products as very soft non‐aqueous gels. Copyright © 2000 John Wiley & Sons, Ltd.