Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9559752 | Polymer | 2005 | 11 Pages |
Abstract
The reaction between a hydrogenated hydroxyl-functionalized polyisoprene (H-HTPI) and isophorone diisocyanate isocyanurate (I-IPDI) is followed by using direct FTIR spectroscopy. The reaction kinetics is studied using a simple model taking into consideration the I-IPDI structure. The rates of individual isocyanate groups are described by a second order equation. Influence of dibutyltin dilaurate (DBTL) concentration and temperature on selectivity, defined as the ratio between the rate constant of secondary isocyanate group and the rate constant of the primary isocyanate group, is investigated. It is observed that selectivity decreases when temperature or DBTL concentration increases. Eyring parameters are determined for the catalyzed [ÎH*=77/35 (kJÂ molâ1), ÎS*=12/â100 (JÂ molâ1Â Kâ1)] and uncatalyzed reactions [ÎH*=48/43 (kJÂ molâ1), ÎS*=â179/â167 (JÂ molâ1Â Kâ1)] primary and secondary isocyanate groups being differentiated.
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
F. Burel, A. Feldman, C. Bunel,