A new route toward imidazoline-functionalized porous polymeric materials from corresponding polystyrene-polylactide diblock copolymers

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• 作者：Joaquin Arredondo^a ; ¹ ; Luis Ernesto Elizalde^a ; ^{luis.elizalde@ciqa.edu.mx" class="auth_mail" title="E-mail the corresponding author} ; Benjamin Le Droumaguet^b ; Daniel Grande^b ; ^{grande@icmpe.cnrs.fr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：ATRP ; ROP ; Diblock copolymers ; Imidazoline groups ; Microphase segregation ; Porous materials
• 刊名：Reactive and Functional Polymers
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：104
• 期：Complete
• 页码：62-70
• 全文大小：1172 K

文摘

Novel imidazoline-functionalized diblock copolymers based on polystyrene (PS) and poly(D,L-lactide) (PLA) were synthesized as precursors to corresponding functional PS-based porous materials through a three-step sequential methodology starting from an asymmetric heterobifunctional initiator. α-Hydroxyl poly(4-cyanostyrene-co-styrene) random copolymers were first obtained via an atom transfer free-radical polymerization (ATRP) procedure by varying the amount of 4-cyanostyrene in the comonomer feed. Cyano groups were then transformed into corresponding imidazoline rings. Subsequently, the microwave-assisted ring-opening polymerization (ROP) of d,l-lactide from the imidazoline-functionalized PS-based macroinitiators allowed for the generation of semi-degradable diblock copolymers with different PLA volume fractions so as to develop microphase-separated morphologies. The precursors and resulting copolymers were analyzed by ¹H, ¹³C NMR, and FT-IR spectroscopy. Upon induced shear-flow via channel-die processing, oriented materials constituted of PLA nanodomains in a polystyrene-based continuous matrix were formed. Hydrolysis in alkaline conditions of the PLA sacrificial block yielded imidazoline-functionalized porous PS-based matrices. The resulting porous frameworks were analyzed by scanning electron microscopy (SEM) and nitrogen sorption porosimetry.