Equilibrium polymerization of 1.3‐dioxolane

Abstract

Equilibrium polymerizations of 1.3-dioxolane and some related cyclic formals have been studied in benzene solution by using boron fluoride ethyl ether complex as a catalyst. From the relation between equilibrium monomer concentration and polymerization temperature, the thermodynamic parameters of the polymerization of these cyclic formals were evaluated as follows:AHp = -3.6 f 0.6 kcal/mole, AS: = -14 f 2 cal/mole.deg. AHp = -3.2 f 0.5 kcal/mole, AS: = -9.3 f I .4 cal/mole*deg. 0.8 kcal/mole, AS: = -9.3 f 1.4 cal/mole-deg. ZUSAMMENFASSUNG: Die Gleichgewichtspolymerisation von 1.3-Dioxolan und einiger abgeleiteter cyclischer Formale wurde unter Anwendung des Bortriiluorid/~thylither-Komplexes als Katalysator in benzolischer Losung untersucht. Aus der Beziehung zwischen Gleichgewichtskonzentratiori des Monomeren und Polymerisationstemperatur wurden die thermodynamischen Polymerisationsparameter wie folgt ermittelt : 1.3-Dioxolan: AHp = -3,6 f 0,6 kcal/mol, AS: = -14 f 2 cal/mol.grad 1.3-Dioxepan: AHp = -3,2 f 0,s kcal/mol, AS: = -9,3 f 1,4 cal/mol-grad 1.3.6-Trioxocan: AHp = -5,3 rt 0,8 kcal/mol, AS: = -9,3 f 1,4 cal/mol*grad * ) Revised manuscript, December 12th, 1967.

Stable organic cation salts: Ion pair equilibria and use in cationic polymerisation

“…Since then a number of groups of research workers have shown interest in these monomers, particularly in 1,3-dioxolan 12 (54, i44-147) and to a lesser extent 1,3-dioxepane 13 (148)(149)(150) The corresponding SbF;-salt provides a cleaner system (118) and possibly the reaction responsible for initiation is indeed a simple alkylation step, though it seems that a relatively small proportion of the added salt…”

Ring-Opening Polymerization of Macrocyclic Acetals

“…They found that the number average molecular weight of the polymer remains almost constant throughout the polymerization (DP ^v>3o) in dicating that the rate of initiation is considerably lower than that of propagation and that the polymeri zation is accompanied by some chain breaking reactions. The thermodynamic parameters of the equilibrium poly merization of 111 (and some related cyclic formais) was studied in more detail by Yamashita et al (22) and by Busfield and Lee (44). Furthermore, it was postulated that the polymer degraded exclusively to monomer in the presence of boron trifluoride.…”

“…The polymerization mechanism does not only depend on the monomer, but also on the initiator and the experimental conditions. In particular the polymerization of 1.2.-and 1.3-epoxides (1)-(5);(18); (19); tetrahydrofurane (1)-(4);(6); (20); dioxolane (21); (22) and trioxane (11); (23)-(26) was thoroughly investigated. For reviews see (4);(8);(27);(28); (30).…”

Ring-chain equilibria and the conformations of polymer chains

“…The effect of the catalyst boron triflueride diethyl etherate on the polymerisation of 1,3-dioxolane has also been studied and it has been found that equilibrium between monomeric 1,3-dioxolane and poly(1,3-dioxolane) is set up in both the undiluted polymer and in solution (101)(102)(103)(104). Controversy has arisen as to whether the equilibrium is between cyclic monomer and cyclic polymer (98) or between cyclic monomer and chain polymer (104).…”