Semicrystalline rubber diblock copolymers via cyclooctene ROMP and chain transfer with vinyl-terminated isotactic polystyrene

Abstract

INTRODUCTION Ring-opening metathesis polymerization (ROMP) represents a versatile synthetic method enabling molecular engineering of a wide variety of polymeric materials for diversified applications. 1,2 Owing to the robustness of the ruthenium-based Grubbs' catalysts, 3,4 both non-polar cyclic olefin monomers and monomers bearing functional groups are tolerated in the ROMP process. The most common ROMP monomers include cyclic olefins such as cyclooctene, [5][6][7][8][9] and norbornene derivatives. [10][11][12] Today, the ROMP process is of particular interest in block and graft copolymer synthesis. semicrystalline polybutadiene-block-isotactic polystyrene (iPS) as semicrystalline rubber block copolymers by means of the living styrene/butadiene copolymerization on isospecific titanate complexes using sequenced feed of styrene and butadiene. Herein, we report on the synthesis of polycyclooctene-b-iPS (PCO-b-iPS) copolymers prepared by means of cyclooctene ROMP using vinyl-terminated iPS (vinyl-iPS) as the CTA, which is readily available by isospecific styrene polymerization in the presence of 1,9-decadiene. EXPERIMENTAL MaterialsAll reactions involving air-and/or moisture-sensitive compounds were carried out under a dry argon atmosphere using standard Schlenk techniques and a glove box (MBraun MB 150B-G-II). Ethyl vinyl ether (99%), 2,6-di-tert-butyl-4-methylphenol (BHT) and the Grubbs first Generation Catalyst benzylidene-bis(tricyclohexylphosphine)dichlororuthenium (G1) were purchased from Sigma and used as received. Ciscyclooctene (Sigma) was dried over CaH 2 and distilled under reduced pressure. Toluene (Sigma) was purified by using a Vacuum Atmospheres Co. solvent purifier. Vinyl-iPS was synthesized with the methylaluminoxane-activated metallocene

Engineering of Syndiotactic and Isotactic Polystyrene-Based Copolymers via Stereoselective Catalytic Polymerization

“…When this copolymer was mixed with sPS-aPS blends, cristallization rates where found in the order sPS > sPS- b -aPS ~ blend sPS- b -aPS/sPS/aPS > blend sPS/aPS, and a significant improvement of the impact strength of the blends was achieved compared to that of pure sPS and their pure blends [ 38 , 110 ]. More recently, iPS- b -PCO copolymer was synthesized via ring-opening metathesis polymerization (ROMP) of cycloctene promoted by Grubbs I catalyst in the presence of iPS-CH 2 CH=CH(CH 2 ) 5 CH=CH 2 macromonomer used as chain-transfer agent [ 111 ]. This material seemed also promising as iPS-thermoplastic elastomers blends compatibilizer.…”

Polycaryophyllene as a Promising Plasticizer for Ethylene Propylene Diene Monomer Elastomers

“…Herein, we report the one-pot ROMP of caryophyllene with controlled molar mass by the presence of styrene as a chain transfer agent (CTA). Indeed, it is well known that mono-olefins such as styrene enable the control of MW during ROMP. − Our approach considered varying the molar ratios of the monomer to CTA leading to the preparation of Pcar of different molar masses and thus T g . The styrene-capped Pcar was characterized by 1 H NMR, heteronuclear single quantum spectroscopy (HSQC), heteronuclear multiple bond correlation (HMBC), diffusion ordered spectroscopy (DOSY), size exclusion chromatography (SEC), and differential scanning calorimetry (DSC).…”