Expts. of Me methacrylate dispersion polymn. are carried out in a reaction calorimeter using PDMS-mMA (methacrylate-terminated polydimethylsiloxane) as surfactant. Different stabilizer concns. from 0 to 10 wt% with respect to monomer have been considered in order to control particle morphol. The anal. by SEM reveals a definite decrease of the total particle surface area at decreasing stabilizer concn. At the same time, the anal. of the polymer microstructure by gel permeation chromatog. shows a trend of the av. mol. wt. towards smaller values. In particular, a second mode at low mol. wts. has been obsd. leading to bimodal mol. wt. distributions. The exptl. results are compared with simulation results obtained through a detailed kinetic model developed in previous studies. The key role of the radical exchange between continuous and dispersed phases is confirmed.
Titre
Dispersion polymerization of methyl methacrylate in supercritical carbon dioxide: control of molecular weight distribution by adjusting particle surface area
Publié dans
Macromolecular Symposia
Volume
259
Numéro
Polymer Reaction Engineering--International Workshop, 2007
Pages
218-225
Date
2007
Note
CAN 148:308707, 35-4, Chemistry of Synthetic High Polymers, DuPont Engineering Research & Technology,Experimental Station,Wilmington,DE,USA., Journal, 1022-1360, written in English., 78-67-1 (AIBN) Role: CAT (Catalyst use), USES (Uses) (dispersion polymn. of Me methacrylate in supercrit. carbon dioxide with emphasis on control of mol. wt. distribution by adjusting particle surface area); 124-38-9 (Carbon dioxide) Role: NUU (Other use, unclassified), USES (Uses) (dispersion polymn. of Me methacrylate in supercrit. carbon dioxide with emphasis on control of mol. wt. distribution by adjusting particle surface area); 9011-14-7P (PMMA) Role: PRP (Properties), SPN (Synthetic preparation), PREP (Preparation) (dispersion polymn. of Me methacrylate in supercrit. carbon dioxide with emphasis on control of mol. wt. distribution by adjusting particle surface area); 1066-42-8D (Dimethylsilanediol) Role: TEM (Technical or engineered material use), USES (Uses) (surfactant acting as PMMA particle stabilizer; dispersion polymn. of Me methacrylate in supercrit. carbon dioxide with emphasis on control of mol. wt. distribution by adjusting particle surface area)
Date de création de la notice
2009-02-09