02153nas a2200217 4500008004100000022001400041245008800055210006900143260005700212300001200269490000700281520136000288653003301648653002801681653001401709653002101723653002401744100002501768700002001793856012201813 2009 eng d a0170-083900aNovel allylic phosphonium salts in free radical accelerated cationic polymerization0 aNovel allylic phosphonium salts in free radical accelerated cati a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcMAR a271-2800 v623 a

In the present study, the synthesis and evaluation of novel allylic phosphonium salts as addition fragmentation agents in combination of conventional (photo-/thermal) free radical source for cationic polymerization are described. The amide based allylic phosphonium salts, namely 2-(N, N-dimethylcaboxy-propenyl) triphenylphosphonium hexafluoroantimonate (DMTPH) and 2-(morpholinocarboxy-propenyl) triphenyl phosphonium hexafluoroantimonate (MTPH) were synthesized and characterized. The thermal and photo-latency of these salts was examined with and without free radical sources in bulk polymerization of cyclohexene oxide (CHO) salts at 70 A degrees C and lambda > 290 nm irradiation, respectively. In presence of thermal free radical source, the order of activity was observed as PAT > BPO > AIBN. The order of activity of free radical sources on photopolymerization was found to be benzoin > benzophenone > TMDPO. In addition, photopolymerization of other cationically polymerizable monomers (such as n-butyl vinyl ether, isobutyl vinyl ether, N-vinyl carbazole and glycidyl phenyl ether) was also examined at lambda > 290 nm irradiation. It is concluded that the rate of cationic polymerization can be accelerated using novel phosphonium salts with combination of free radical sources, by both thermal and photochemical mode.

10aAddition fragmentation agent10aCationic polymerization10aInitiator10aphosphonium salt10aPhotopolymerization1 aGupta, Mukesh, Kumar1 aSingh, Raj, Pal uhttps://library.ncl.res.in/content/novel-allylic-phosphonium-salts-free-radical-accelerated-cationic-polymerization-002023nas a2200217 4500008004100000022001400041245010200055210006900157260006800226300001400294490000800308520121900316653002801535653002601563653001501589653002101604653001701625100002501642700002001667856011801687 2009 eng d a0021-899500aNovel dibenzocycloheptenyl phosphonium salts as thermolatent initiator in cationic polymerization0 aNovel dibenzocycloheptenyl phosphonium salts as thermolatent ini a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcJUN a3707-37130 v1123 a

In this study, novel thermolatent cationic initiators based on dibenzocycloheptenyl phosphonium salts (1a, 1b, 1c, 1d, 2a, and 3a) were synthesized and their efficiency was examined in bulk polymerization of glycidyl phenyl ether (GPE). The polymerization of GPE was performed with 1 mol % of dibenzocycloheptenyl triphenylphosphonium salts (1a-1d) with different counter anions (SbF(6)(-), PF(6)(-), AsF(6)(-), and BF(4)(-)) at 25-200 degrees C for 1 h. The order of initiator activity was found as 1a > 1d > 1b > 1c. To examine the effect of phosphine moiety, the activity of la was compared with dibenzocycloheptenyl-tri-n-butylphosphonium hexafluoroantimonate (2a). The order of initiator activity was observed as 1a > 2a. The initiator activity of la was compared with that of 10,11-dihydro-dibenzocycloheptenyltriphenylphosphonium hexafluoroantimonate (3a) to understand the effect of extended conjugation in dibenzocycloheptenyl ring. In general, with the increase in the polymerization temperature, conversion (%) also increases. The solubility of initiators in various solvents and epoxy monomers was also examined. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 3707-3713, 2009

10aCationic polymerization10aglycidyl phenyl ether10ainitiators10aphosphonium salt10athermolatent1 aGupta, Mukesh, Kumar1 aSingh, Raj, Pal uhttps://library.ncl.res.in/content/novel-dibenzocycloheptenyl-phosphonium-salts-thermolatent-initiator-cationic-001761nas a2200241 4500008004100000022001400041245007100055210006900126260005700195300001000252490000700262520094200269653003301211653001801244653001701262653002801279653001501307653002401322100002501346700002301371700002001394856010501414 2010 eng d a0170-083900aNovel addition-fragmentation agent in cationic photopolymerization0 aNovel additionfragmentation agent in cationic photopolymerizatio a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUN a25-340 v653 a

The aim of present study is to examine the photo-initiation efficiency of N,N-dimethylacrylamide-based allylic ammonium salt as one component addition-fragmentation agent (cationic photoinitiator cum radical source) in free radical accelerated cationic polymerization. Novel addition-fragmentation agent (AFA), 2-(N,N-dimethylcarboxy-3-propenyl)(phenylcarbonyl-4-phenylene) dimethyl ammonium hexafluoroantimonate (DMPDA) was synthesized as cationic photoinitiator and its initiation efficiency was examined in polymerization of cyclohexene oxide (CHO), isobutyl vinyl ether (IBVE), and n-butyl vinyl ether (n-BVE) in CH(2)Cl(2) solvent at wavelength lambda > 290 nm. The rate of polymerization increases with the increase in initiator concentration and reaction time. The results demonstrate that DMPDA acts as an efficient photoinitiator (AFA) without use of radical source in free radical accelerated cationic polymerization.

10aAddition-fragmentation agent10aAmmonium salt10aBenzophenone10aCationic polymerization10aOnium salt10aPhotopolymerization1 aGupta, Mukesh, Kumar1 aMehare, Rupali, S.1 aSingh, Raj, Pal uhttps://library.ncl.res.in/content/novel-addition-fragmentation-agent-cationic-photopolymerization-0