Temperature‐Responsive Water‐Soluble Copolymers Based on 2‐Hydroxyethyl Acrylate and Butyl Acrylate

Abstract

Amphiphilic copolymers have been synthesised by free radical copolymerisation of 2‐hydroxyethyl acrylate with butyl acrylate, the reactivity ratios of which indicate practically equal reactivity. The copolymers containing less than 30 mol‐% of BA were soluble in water and exhibited a LCST in aqueous solutions. It was found that the interaction between these copolymers and poly(acrylic acid) in aqueous solutions resulted in the formation of interpolymer complexes stabilised by hydrogen bonds and hydrophobic interactions. This interaction was significantly affected by solution pH and led to modification of the temperature‐responsive behaviour of the copolymers.magnified image

The formation of interpolymer complexes and hydrophilic associates of poly(acrylic acid) and non-ionic copolymers based on 2-hydroxyethylacrylate in aqueous solutions

“…Pyrene, hydrochloric acid, HEA, BA and PAA with weight‐average molecular weight of 250 and 750 kDa were purchased from Aldrich Chemical Co. (USA) and used without further purification. The synthesis of PHEA and copolymer HEA‐ co ‐BA as well as their characteristics are described elsewhere …”

“…In the work reported here, interactions between poly(acrylic acid) (PAA) and poly(2‐hydroxyethylacrylate) (PHEA) as well as with a hydrophilic copolymer of 2‐hydroxyethylacrylate (HEA) and butylacrylate (BA) were analysed. On the one hand, the choice of pairs of polymers is determined by the fact that the given pair of interacting polymers has been already investigated quite comprehensively using turbidimetric methods . On the other hand, there are as yet no experimentally confirmed data concerning the existence of two threshold values of pH for this system.…”

A quantum chemistry study of the free‐radical copolymerization propagation kinetics of styrene and 2‐hydroxyethyl acrylate

“…In particular, the free radical copolymerization kinetics was investigated to get a good understanding of the mechanism of copolymer chain‐growth [1–7]. Copolymers based on 2‐hydroxyethyl acrylate (HEA) were reported by copolymerization with ethers, acrylates, or methacrylates [8–13]. Notably, HEA is a functional monomer whose copolymers are also useful as biomaterials [14–17].…”

Nitroxide‐Mediated Copolymerization of 2‐Hydroxyethyl Acrylate and 2‐Hydroxypropyl Acrylate: Copolymerization Kinetics and Thermoresponsive Properties

“…Only in recent years, it was demonstrated that HPA can be copolymerized with more hydrophilic monomers, such as N ‐acryloylmorpholine, N , N ‐dimethylacrylamide, and aminoethyl methacrylate hydrochloride, to tune the LCST from 16 to 88 °C 21, 22. In addition, several examples of thermoresponsive copolymers based on 2‐hydroxyethyl acrylate (HEA) have been reported by copolymerization with the more hydrophobic vinyl butyl ether, n ‐butyl acrylate or 2‐hydroxyethyl methacrylate 23–25. In fact, PHEA is an interesting biomaterial25–28 with similar biocompatibility, including cytotoxicity, thermal stability, as well as cell compatibility,29–31 as poly(2‐hydroxyethyl methacrylate), which is widely used in, e.g., contact lenses.…”