Polymerization of Methyl Methacrylate in the Presence of Boroxyl Radicals. Synthesis of Block Copolymers

Properties of Copolymers of Butyl Acrylate with Vinyl Isobutyl Ether Obtained Using the Triethylborane – Oxygen System by the Compensating Method

“…Полученные данные дают основание предположить, что при сополимеризации БА с ВиБЭ в указанных условиях, как и в случае БА с ВБЭ [2], имеет место образование макромолекулярной цепи по двум центрам: олигомерному и низкомолекулярному, что в данном случае приводит к образованию большого олигомерного плеча (для ВБЭ наблюдали две моды -олигомерную и низкомолекулярную [2]). Образование олигомера наряду с низкомолекулярным полимером (M n ~ 30-40 кДа), обычно формирующимся в таких условиях при традиционном радикальном инициировании, например, динитрилом азоизомасляной кислоты (ДАК) [11], как и для мономерной пары БА-ВБЭ [2] объясняется присутствием в реакционной смеси бороксильного радикала, который известен при окислении триалкилборанов [18][19][20][21]. За счет взаимодействия последнего, с инициирующими, R• или RO•, которые также зафиксированы при окислении триалкилборанов [18], или олигомерными растущими радикалами формируется центр роста полимерной цепи по механизму обратимого ингибирования (схема 1) с очень низкой степенью полимеризации (M n~ 0,5-1,0 кДа).…”

New method for controlled synthesis of polylactide block copolymers: organoborane/p‐quinone system and reversible‐deactivation radical polymerization

“…Chung et al discovered that polymerization of some monomers in the presence of a trialkylborane/atmospheric oxygen system proceeds in a controlled manner due to the dissociation-recombination of active terminal borane fragments. 35 Polymerization in the presence of trialkylboranes and atmospheric oxygen has been studied in detail by Zaremski et al [36][37][38] Using different macroinitiators, compositionally homogeneous random, grafted and block copolymers derived from synthetic monomers were synthesized, [39][40][41][42] as well as hybrid copolymers with natural substrates such as cotton, 43 hemoglobin, 44 chitin 45 and gelatin. 46 Organoborane/atmospheric oxygen systems also have biomedical applications.…”

“…Polymerization in the presence of trialkylboranes and atmospheric oxygen has been studied in detail by Zaremski et al 36–38 . Using different macroinitiators, compositionally homogeneous random, grafted and block copolymers derived from synthetic monomers were synthesized, 39–42 as well as hybrid copolymers with natural substrates such as cotton, 43 hemoglobin, 44 chitin 45 and gelatin 46 . Organoborane/atmospheric oxygen systems also have biomedical applications.…”

Alkylboranes in Conventional and Controlled Radical Polymerization

“…For example, polymerization of MMA using 7.2 mM TEB in the presence of 5.4 mM concentration of oxygen provided PMMA with M n = 185,000 and M w / M n = 2.7 in 2.5 h. Less active organoboranes were also investigated such as boracyclanes (2‐BAD) and ammonia complex of trialkylboranes (Bu 3 B–NH 3 and Et 3 B–NH 3 ) . In the aspects of monomer scopes, acrylate, acrylic acid vinyl acetate, methacrylate, acrylonitrile, and vinylidene fluoride were all successfully polymerized using organoborane/oxygen initiation systems.…”