Zur kenntnis der perlpolymerisation. 1. Mitt. grundlagen

Abstract

ZUSAMMENFASSUNG:Apparatur und Methode zur Untersuchung der Perlpolyrnerisation werden beschrieben. Es kann gezeigt werden, daB die GroSe der anfallenden Perlen zu Beginn des Versuchs, bevor die Polymerisation einen merklichen Umsatz erreicht hat, festgelegt wird. Dadurch wird es erstmals moglich, eine Dimensionsanalyse fur die Perlpolymerisation konsequent durchzufuhren. Zur Auswertung der Resultate miissen rnit Hilfe der Ausbeute korrigierte PerlgroBen verwendet werden. Die Resultate der Versuche mit verschiedenen Initiatormengen stehen mit den entwickelten Vorstellungen im Einklang. SUMMARY:Equipment and method for the investigation of suspension polymerisations are described. iIt can be shown that the size of the pearls is determined at the beginning of the experiment6 before a noticeable conversion has taken place. This allows for the first time be consequently carry out a dimensional analysis of the suspension polymerisation process. For the evaluation of the results a modified pearl size, taking the varying yield into account, must be introduced. The results of the experiments with different initiator additions are in agreement with the developed ideas.

Development of a suspension copolymerization process for bone cement production

“…By means of dimensional analysis, Hopff et al 16 derived a simplified potential equation relating both parameters, in the case of a suspension polymerization of methyl methacrylate. The weight-average particle size, d w (cm), vs. the agitation rate, N (s Ϫ1 ), in logarithmic scales has been drawn out in Figure 5.…”

Polymerization Reaction Engineering

“…The major new problems are stabilization of the viscous polymer drops, prediction of particle size distribution, etc. Particle size distribution was found to be determined early in the polymerization by Hopff et al (28,29,40). Church and Shinnar (12) applied turbulence theory to explain the stabilization of suspension polymers by the combined action of protective colloids and turbulent flow forces.…”

Size distribution of suspension‐polymerized unsaturated polyester beads

“…The amount of protective suspension stabilizer required is thus reduced in this case. The range of PMMA bead size covered by Hopff et al 6 was approximately 15 to 100 p (1% to 5% PVAI), while in the present work the polyester bead size is in the range of 200 to 2000 p (0.05% to 0.6% medium-viscosity PVAI).…”

“…Further analysis of the distribution curves has shown that they can be described approximately by (6) where W is the cumulative weight fraction and a and b are empirical constants.…”