Polymerization of 3,3‐bis (chloromethyl) oxetane catalyzed by i‐Bu₃Al in bulk. I. The conditions of high polymer formation

Abstract

S U M M A R Y :The high temperature (up to 220 "C.) polymerization of 3,3-bis(chloromethyl)oxetane catalyzed by i-Bu,Al was investigated. The conversion-time curves are of the autocatalytic type and the molecular weight increases lineary with conversion up to the point a t which for lower temperatures, e.g. 60-80 "C., the whole polymer becomes insoluble. An alternative explanation of this phenomenon is proposed; the formation of insoluble product is related to the entanglement of macromolecules of very high molecular weight and /or macrocycle formation in the degradative chain transfer to poIymer. The phenomenon of insoluble pioducts formation was never observed a t higher temperatures (> 150 "C.).The dependence of molecular weight on catalyst and impurity concentrations as well as on the polymerization temperature was investigated. It was shown that the high molecular weight product (m = 1000-1500) can be produced at 180-220 'C. even at rather high impurity level. ZUSAMMENFASSUNG:Die Hochtemperaturpolymerisation (bis 220 "C) von 3,3-Bis(chlormethyl)oxetan, katalysiert durch i-Bu,Al, wurde untersucht. Die Zeit-Umsatzkurven sind autokatalytisch, und das Molekulargewicht steigt linear mit dem Umsatz bis zu einem Punkt, wo bei tieferer Temperatur (z. B. 60-80 "C) das ganze Polymere unloslich wird. Eine andere Erkliirungsmoglichkeit dieses Verhaltens wird vorgeschlagen; die Bildung des unloslichen Produkts hangt zusammen mit der Verknauelung von Makromolekulen sehr hohen Molekulargewichts und /oder Makro-Ringbildung bei der abbauenden Ketteniibertragung mit dem Polymeren. Das Phanomen der Bildung unloslicher Polymerer wurde bei hoherer Temperatur (> 150°C) nicht beobachtet. Die Abhangigkeit des Molekulargewichts von der Konzentration an Katalysator oder Verunreinigung sowie von der Temperatur wurde untersucht. Es konnte gezeigt werden, dal3 das hochmolekulare Produkt (Ep = 1000-1500) bei 180-220°C sogar bei ziemlich hohem Anteil an Verunreinigungen erhalten werden kann. *) Revised manuscript, August 16, 1965. 228 Polymerization of 3,3-Bis(chloromethyl)oxetanePolymerization of 3,3-bis(chloromethyl)oxetane catalyzed by aluminum alkyls was the subject of several U.S. patents1). The polymerization in solution and in precipitating media was described by KAMBARA and H A T A N O~) as well as by KROPACHOV, DOLGOPLOSK, and GELLER394).The discovery of new and very effective catalysts based on modified a hminum alkyls is connected with the investigations of Japanese schools and described in several papers of FURUKAWA, SAEGUSA and their coworkers 5). However, the scope of the earlier investigations was limited and even the conversion-time dependence for this type of polymerization was not known with certainty.The purpose of the present work is the bulk polymerization of 3,3-bis-(chloromethy1)oxetane a t temperatures near the polymer melting point, 180°C., and well above, where polymer melt could be processed. Experimental3,3-bis(chloromethyl)oxetane was prepared as previously described6*'). Immediately before use monomer was dis...

Polymerization of Bis-Oxetanes Consisting of Oligo-Ethylene Oxide Chain with Lithium Salts as Initiators

“…5 It is difficult to suppress rapid ring-opening polymerization of the oxetanes with LiBF 4 and LiPF 6 , because the lithium salts which are as active as general cationic catalysts to oxetanes, are introduced into the oxetane in much larger quantities ( 30 wt%) than the usual amounts of catalysts (ca. 0.5 wt%) 12 in order to use the polymer-lithium salt complexes as polymer electrolytes. Figure 3 shows variation in viscosity of the mixture that consists of DDOE, a lithium salt, and a polar solvent.…”