Preparation and self‐assembly behavior of thermosensitive polymeric micelles comprising poly(styrene‐b‐N,N‐diethylacrylamide)

Abstract

The amphiphilic block copolymer poly(styrene-b-N,N-diethylacrylamide) (PSt-b-PDEA) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene and N,N-diethylacrylamide. The results of 1 H-NMR and GPC analysis showed that the synthesized PSt-b-PDEA copolymer had controlled molecular weight and narrow polydispersity. Polymeric micelles having a unimodal size distribution with an average diameter of 40 AE 0.5 nm were obtained from purified PSt-b-PDEA using a dialysis method. And the results showed that the clearance of homopolymer in copolymer is the key to prepare the unimodal distribution core-shell nanomicelles. The micelles were thermodynamically stable in aqueous media with a low critical micelle concentration value (0.1 mg L À1 ). The aqueous micelles solution underwent a reversible dispersion/ aggregation transition at around 298C, which corresponds to the lower critical solution temperature (LCST) of the outer shell PDEA block chains. It is hoped that with their unique characteristics, those thermoresponsive polymeric micelles would found application in drug delivery.

Polymeric micelles: authoritative aspects for drug delivery

“…Bian et al synthesized poly(styrene-b-N,N-diethylacrylamide) with controlled molecular weight and narrow polydispersity [316]. The aqueous micellar solution underwent a reversible aggregation transition at around the LCST of poly(N,N-diethylacrylamide) block chains comprising the outer shell.…”

Triblock copolymers of styrene and sodium methacrylate as smart materials: synthesis and rheological characterization

“…The possibility exists to introduce responsive behavior to parameters such as pH [3][4][5], temperature [6,7] or UV irradiation [2]. The versatility in properties has resulted in an increased attention in the last decades for application in several fields including smart materials [6,7], micro emulsion stabilization [8] and polymerization [9,10], coatings [11], drug delivery [12][13][14] and enhanced oil recovery [2,3,15,16].…”

Dually stimuli‐responsive hyperbranched polyethylenimine with LCST transition based on hydrophilic–hydrophobic balance

“…During this process, an intramolecular coil to globule transition occurs. Besides PNIPAM, PDMAEMA [poly(2‐(dimethylamino)ethyl methacrylate)] and PDEAM [poly( N , N ‐diethylacrylamide)] also belong in this type 33–37. Different from type I, the LCST transitions of type II polymers originate from intermolecular interactions, such as hydrogen bonding and hydrophobic interactions, instead of intramolecular interactions.…”