Synthesis of polystyrene macromonomers for use in polycondensation reactions

Abstract

The preparation of aromatic macromonomers with hydroxyl functions was achieved by termination of living polystyrene (PSLi) upon addition of 2,5-dimethoxybenzyl bromide (2) or l,l-bis(4-methoxyphenyl)ethylene (16). Ether cleavage with boron tribromide resulted in the formation of the de-protected macromonomers 15 and 17. Side reactions occurring in the functionalisation reaction with 2 were investigated by means of @ respective model reaction. The formation of side products could be suppressed by reacting PSLi with 1,l-diphenylethylene prior to functionalisation with 2. The macromonomers were characterized by GPC, UV, and FT-IR spectroscopy.

Recent advance in syntheses and applications of well-defined end-functionalized polymers by means of anionic living polymerization

“…Very interestingly, a few synthetic methods for introducing two or more functional groups at polymer chain ends have been so far reported. Heiz and Hocker [52], and later Quirk and his coworkers [53] were successful to synthesize well-defined end-functionalized polystyrenes with two phenolic hydroxy groups by reacting polystyryllithium with the DPE derivatives 34 and 35 containing two protected phenol-functionalities, followed by deprotection. Eisenberg and Zhong reported that an end-functionalized polystyrene with two carboxy groups was obtained by treating polystyryllithium with dimethyl maleate, followed by hydrolysis of the ester groups [54].…”

Free‐Radical Acrylic Polymerization Kinetics at Elevated Temperatures

“…This equilibrium can be manipulated through choice of operating conditions (temperature and monomer concentration) to purposely generate macromonomer products, which are versatile intermediates extensively used as well-defined building blocks for various macromolecular architectures, e.g., comb [66], star [67], and hyperbranched [68][69][70][71]. Several methods have been described for making macromonomers including anionic polymerization [72], group transfer polymerization [73], addition fragmentation chain transfer [74], living radical polymerization [75,76], and catalytic chain transfer to alkyl cobalt complexes [77][78][79][80][81]. Many of these routes are difficult to carry out and involve high cost at industrial scale.…”

Synthesis of well-defined functionalized polymers and star branched polymers by means of living anionic polymerization using specially designed 1,1-diphenylethylene derivatives

“…Successful demonstrations of this methodology in the synthesis of phenol end-functionalized polystyrenes have been reported independently by Heitz, Höcker in 1988 [9] and Quirk, Zhu in 1989. [10] These could be achieved by simply adding either 1,1-bis(4-methoxyphenyl)ethylene (1) or 1-(4-tert-butyldimethylsilyloxyphenyl)-1-phenylethylene (2) to poly(styryllithium)s. A polystyrene (M -n = 2.07 kg/mol, M -w /M -n = 1.05 having two phenolic functions at the chain end was quantitatively obtained after deprotection of the methoxy groups with BBr 3 .…”

“…Surprisingly, both a-methylstyryl and 1,3-butadienyl functions which are readily polymerizable with the living anionic polymers could be quantitatively introduced to the chain ends by reacting both poly(styryllithium) and poly(isoprenyllithium) with 1-{4-[3-(3-isopropenylphenyl)propyl]phenyl}-1-phenylethylene (8) [16] and 1-[4-methylene-5-hexenyl)phenyl]-1-phenylethylene (9), [17] respectively. Moreover, the resulting 1,1-diphenylalkyl anions at the chain ends after addition reaction to 8 and 9 were stable at -78 8C in THF even after 24 h. The results are summarized in Tab.…”

“…Two functional groups can be introduced into the chain ends by reacting living anionic polymers simply with substituted DPE derivatives with two functional groups as illustrated in Scheme 4. In fact, x,x-bis(phenol) end-functionalized polystyrenes were successfully synthesized by addition reaction of poly(styryllithium)s to either 1 [9] or 1,1-bis(4-tert-butyldimethylsiloxyphenyl)-ethylene (10), [21] followed by deprotection of the methyl or silyl groups.…”