New approaches to hyperbranched poly(4‐chloromethylstyrene) and introduction of various functional end groups by polymer‐analogous reactions

Abstract

A facile way for the synthesis of hyperbranched poly(4‐chloromethylstyrene) [P(4‐CMS)] with adjustable molar mass by classic atom transfer radical polymerization (ATRP) and mechanistically similar procedures is presented. Subsequently, the chlorine functional groups have been modified to obtain polymers with different polarities. On the one hand, the polymer was end‐capped with unpolar groups (e.g., methyl, phenol ether) to obtain chemically inert substances. On the other hand, more complex functional groups have been introduced through azide groups by 1,3‐dipolar cycloaddition reaction (“click chemistry”). Furthermore, a method for the introduction of ester groups under mild conditions using cesium carboxylates is presented, which also allowed the preparation of so‐called hyperstars by attaching COOH functionalized polystyrene chains onto the P(4‐CMS) as core molecule. All these reactions were carried out in high or very high yields. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2224–2235, 2010

The radius of gyration for a ternary self-condensing vinyl polymerization system

“…(19) also hold true when the solvent effect and excluded volume interaction are taken into account [27]. This is because that the two factors mentioned above are independent of x and .…”

Preparation of hyperbranched polystyrene-g-poly(N-isopropylacrylamide) copolymers and its application to novel thermo-responsive cell culture dishes

“…The molecular weight of P1 was M n ¼ 7.0 Â 10 3 and M w /M n ¼ 2.76. As illustrated in Scheme 2, P1 was converted into P2, P3 and P4 through the reaction with sodium azide [19], introducing CTA, and RAFT polymerization of N-isopropylacrylamide (NIPAM) [9], respectively. An azide group, which is the reactive group for the click reaction, was introduced by a simple replacement reaction of the chlorine atom of P1 using sodium azide to form P2.…”

“…CTA-terminated HBPSt (P3) was prepared by the click reaction of P2 and propargyl-terminated CTA (Scheme 2) [19]. For example, P2-33 (1.18 g, 1.50 mmol of azide group), propargyl-terminated CTA (0.908 g, 2.25 mmol), Cu(PPh 3 ) 3 Br (30 mg) and DMF (20 mL) were placed in a 100-mL flask.…”

“…Azide-terminated HBPSt (P2-XX) was prepared by the reaction of P1 and sodium azide (Scheme 2) [19], where XX represents the stoichiometric percentage of the reacted azide ( Fig. 1).…”

Synthesis of long‐subchain hyperbranched PCL through SCV‐ATRP of macroinimers with (meth)acrlate group

“…Thus, various considerations have been afforded to control the branching structure. 9,[22][23][24][25][26][27] It can be expected that SCVP of macroinimers could introduce the subchains with regular length into highly branched polymers, which has been adopted in the preparation of dendrimer-like polymers. 28 However, to the best of our knowledge, very little attempts have been made to synthesis lsc-hb polymers via self-condensing vinyl atom transfer radical polymerization (SCV-ATRP) of macroinimers.…”