Polymerization and copolymerization of functionalized 2‐alkoxy‐1‐methylenecyclopropanes to form new polymers having alkoxy substituents

Abstract

The polymers with functionalized alkoxy groups and with narrow molecular weight distribution (Mw/Mn < 1.12) are obtained from the living polymerization of 2‐alkoxy‐1‐methylenecyclopropanes using π‐allylpalladium complex, [(PhC3H4)Pd(μ‐Cl)]2, as the initiator. The polymers with oligoethylene glycol groups in the alkoxy substituent are soluble in water, and hydroboration of the CC double bond and ensuing addition of the OH groups to CN bond of alkyl isocyanate produce the polymers with urethane pendant groups. The reaction decreases solubility of the polymer in water significantly. Di‐ and triblock copolymers of the 2‐alkoxy‐1‐methylenecyclopropanes are prepared by consecutive addition of the two or three 2‐alkoxy‐1‐methylenecyclopropane monomers to the Pd initiator. The polymers which contain both hydrophobic butoxy or tert‐butoxy group and hydrophilic oligoethylene glycol group dissolve in water and/or organic solvents, depending on the substituents. The 1H NMR spectrum of poly(1a‐b‐1h) ((CH2C(CH2)CHOBu)n(CH2C(CH2)CH(OCH2CH2)3OMe)m) in D2O solution exhibits peaks because of the butoxy and CH2 hydrogen in decreased intensity, indicating that the polymer forms micelle particles containing the hydrophilic segments in their external parts. Aqueous solution of the polymer with a small amount of DPH (DPH = 1,6‐diphenyl‐1,3,5‐hexatriene) shows the absorbance due to DPH at concentration of the polymer higher than 5.82 × 10−5 g mL−1. Other block copolymers such as poly(1b‐b‐1h) and poly(1a‐b‐1g) also form the micelles that contain DPH in their core. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 959–972, 2009

End‐functionalization of syndiotactic polystyrene by vinylsilane inducing selective chain transfer reactions

“…6) with a high yield. 18 Consequently, CH 2 ¼ ¼CH-capped sPS can undergo subsequent epoxidation, 19 ozonolysis, 20 and hydroboration 21 to produce epoxide-capped, formyl-capped (Fig. 7), and hydroxyl-capped sPS (Fig.…”

Stereoregular Diblock Copolymers of Syndiotactic Polystyrene Derivatives and Polylactide: Syntheses and Self-Assembled Nanostructures

“…For the preparation of syndiotactic polystyrenes containing stereoregular BCPs, the terminal DMPVS group of the C 6 H 5 −Si(CH 3 ) 2 −CHCH-capped syndiotactic polystyrenes were allowed to undergo a desilylation reaction through treatment with trifluoroacetic acid to provide ethenyl group end-capped syndiotactic polystyrenes with high yields . Subsequently, the ethenyl end group of the CH 2 CH-capped syndiotactic polystyrenes can be converted into a hydroxyl group by a subsequent hydroboration reaction . The resulting hydroxyl-capped syndiotactic polystyrenes can be treated with alkylaluminum for conversion into aluminum alkoxide-capped syndiotactic polystyrenes which can act as macroinitiators for mediating the controlled ring-opening polymerization of cyclic esters for the production of syndiotactic polystyrenes- b -polyesters as structurally well-defined stereoregular BCPs. , Of note, the synthesis of the hydroxyl-capped stereoregular polystyrenes is the key step for the successful preparation of the syndiotactic polystyrenes containing stereoregular BCPs since the construction stereoregular BCPs depends on the purity of the macroinitiator, which needs to be generated form a highly pure hydroxyl-capped end-functionalized prepolymer.…”

Aggregation-induced emission behavior of a pincer platinum(II) complex bearing a poly(ethylene oxide) chain in aqueous solution

“…Critical micelle concentration of 2 was determined according to the method reported in the literature [18]. A 20 µL aliquot of a 2.0×10 -3 M solution of Nile Red (NR) in methanol was 10 transferred to 2 mL of an aqueous solution 2 (7.6×10 -6 to 5.8×10 -5 M).…”

“…Incorporation was conducted by reference to the literature [3,18]. Trimesic acid (25 or 50 equivalent for 2) were incorporated into 2 (5×10 -5 M) according to the incorporation method of trimesic acid by 2.…”