Synthesis, Characterization, and Photopolymerization of Polyisobutylene Phenol (Meth)acrylate Macromers

Abstract

Polyisobutylene (PIB) phenol (meth)­acrylates were produced by reacting di- or triphenol-terminated PIB with (meth)­acryloyl chloride. 1H NMR, GPC, and MALDI-TOF MS characterization showed that meth­(acrylate) end-functionality was 2 and 3, respectively, and that targeted molecular weights and relatively low polydispersities were achieved. Comparative aliphatic PIB triol triacrylate was prepared by end-quenching living polyisobutylene with 4-phenoxy-1-butyl acrylate. A photopolymerization study of PIB diphenol di­(meth)­acrylates with M n about 3000 g/mol, PIB triphenol tri­(meth)­acrylates with M n about 4000 and 10 000 g/mol, and control aliphatic PIB triol triacrylate with M n about 10 000 g/mol was conducted. Darocur 1173 and Irgacure 819 and 651 photoinitiators were studied, and FTIR reaction monitoring showed that Darocur 1173 afforded the highest rate of photopolymerization and final conversion, apparently due to its higher solubility in PIB. At M n ≅ 4000 g/mol, the rate of photopolymerization and conversion of PIB triphenol triacrylate was faster than that of PIB triphenol methacrylate under the same conditions; at M n ≅ 10 000 g/mol, PIB triphenol triacrylate, PIB triphenol trimethacrylate, and aliphatic PIB triacrylate all showed the same high rate of photopolymerization, which was higher than any rate observed at M n ≅ 4000 g/mol. Similarly, PIB triphenol tri­(meth)­acrylate at M n ≅ 4000 g/mol displayed a higher rate of photopolymerization and double-bond conversion than PIB diphenol di­(meth)­acrylate at M n ≅ 3000 g/mol, although they have similar chain end concentrations. This phenomenon was attributed to reduced diffusional mobility at higher M n, resulting in decreased rate of bimolecular radical termination and autoacceleration. T g of UV-cured PIB networks decreased as M n of PIB macromer increased regardless of end-group type, and thermal stability of cured networks remained constant regardless of end-group type. Mechanical properties were characteristic of rubbery networks, but weak, apparently due to low M n and low PDI of the starting macromers and lack of chain entanglements. Networks from macromers with M n ≅ 10 000 g/mol gave higher elongations, but lower Young’s moduli, compared to those from macromers with M n ≅ 4000 g/mol.

Polyisobutylene containing covalently bound antioxidant moieties

“…Recently, our laboratory reported the cleavage/alkylation reaction of butyl rubber (F IP = 0.0230) using (3‐bromopropoxy)benzene . The latter is a versatile quencher that yields primary‐bromide functional groups along the PIB backbone for easy synthetic modification . The authors overviewed some general mechanistic considerations of the cleavage/alkylation process; however, their focus on achieving low‐molecular weight, difunctional PIB (~2000 < <5000 g/mol) deviated significantly from the goals of the present study.…”

“…27 The latter is a versatile quencher that yields primary-bromide functional groups along the PIB backbone for easy synthetic modification. 28,32,33 The authors overviewed some general mechanistic considerations of the cleavage/alkylation process; however, their focus on achieving low-molecular weight, difunctional PIB (~2000 < M n <5000 g/mol) deviated significantly from the goals of the present study. Herein, we were interested in conditions whereby the cleavage/alkylation process would yield PIBs with moderate-to-high M n 's, possessing moderately high F n 's.…”

Excellent Gas Barrier Properties PET Film Modified by Silicone Resin/Sericite Nanocomposite Coatings

“…Coating is a solid continuous film obtained by one-time coating. Gas barrier coating is a method of applying a layer of polymer coating [11][12][13] liquid on the film to form a gas barrier coating. At present, the functional silicone resin coating obtained by photo-thermal double [14][15][16] curing technology has the advantages of rapid curing, simple process, energy saving and environmental protection, and does not contain volatile solvents in the curing system, which is in line with the increasing emphasis on the environmental protection concept nowadays.…”

Functionalization of polyisobutylene and polyisobutylene oligomers via the ritter reaction

“…Recently, there has been interest in PIB macromonomers possessing more highly reactive terminal unsaturation, especially (meth)acrylate and vinyl ether . These systems may be cured by thermal or photoinitiated radical chain polymerization, or in the case of vinyl ether, by photoinitiated cationic polymerization.…”