The synthesis of α‐tert‐butyl‐ω‐[p‐vinylphenyl]‐terminated poly(2‐methylpropene) macromonomers

Abstract

poly(2-methylpropene) (PIB) macromonomers (P3 (VB); P5) is described:In this communication a novel synthetic route to a-tert-butyl-o-[p-vinylphenyll-terminated and P5Attempts to synthesize such macromonomers in both one-and two-step syntheses are described. The one-step method using 4-chloromethylstyrene/AlR3 as initiating system for the polymerization of 2-methylpropene did not yield linear macromonomers but rather highly branched products. The alternative two-step synthesis using l-(2-bromoethyl)-4-chloromethylbenzene (BCB) or BCB/AgSbF, as initiator also failed to yield the desired products. Successful synthetic routes, optimised on the basis of model experiments with low molar mass compounds, are also described for preparing the above macromonomers. Both of these routes involve isopropenylterminated PIB, which is easily assessible by Inifer technique followed by dehydrohalogenation. Friedel-Crafts alkylation of phenol by the terminal olefin group of PIB, followed by subsequent esterification of the phenolic end-groups with 4-vinylbenzoyl chloride, affords the macromonomer P3(VB). Conversion of the terminal olefin group of PIB into a primary alcohol using 9-bora[3,3, I]-bicyclononane/H202, followed by esterification, yields the macromonomer P5. ' ) BASF,

Hyperbranched polymers—All problems solved after 15 years of research?

“…Polyethers,6, 12 polyamides,10 poly(ether amide)s,175 poly(ester amide)s,11, 55 polyimides,10 polythioethers,176 polyurethanes,71, 177–180 poly(ether sulfone)s and poly(ether ketone)s,20 polycarbonates,21, 181, 182 poly(phenylacetylene)s,183 polyarylenes1, 84, 185 polysiloxysilanes and polycarbosilanes,186–190 and other structures prepared by AB x monomers (see refs. 1–23) are described in the literature. SCVP22–33 and ring‐opening multi‐branching (transfer) reactions34–40 have further broadened the structural varieties of polymers based on chain growth reactions.…”

One‐pot inimer promoted ROCP synthesis of branched copolyesters using α‐hydroxy‐γ‐butyrolactone as the branching reagent

“…These condensation studies have been well developed with a broad polymer family that includes polyesters, polyamides, polyethers, and polycarbonates . Another strategy that was introduced in mid 1980s to early 1990s by several different groups described the use of a latent AB n monomer in a type of multibranching polymerization . Such monomers behave both as a monomer and as an initiator and are thus termed inimers.…”

Kinetic Evaluation of Hyperbranched A2 + B3 Polycondensation Reactions

“…The drawback is the lack of control over the structure of the resulting polymers. There is a great variety on different synthetic approaches towards branched polymers like polycondensation, [5,6] self condensing vinyl polymerization (SCVP) [7][8][9] or ring-opening multibranching polymerization; [10][11][12] so far the polycondensation approach is the predominant method. The preferred method for the synthesis of hyperbranched polymers is the polycondensation of an AB n monomer (n > 1).…”