Synthesis and Phase Behavior of Poly(N-isopropylacrylamide)-b- Poly(L-Lysine Hydrochloride) and Poly(N-Isopropylacrylamide- co-Acrylamide)-b-Poly(L-Lysine Hydrochloride)

Milica Spasojević; Joop Vorenkamp; Mark R P A C S Jansen; Paul de Vos; Arend Jan Schouten

doi:10.3390/ma7075305

Synthesis and Phase Behavior of Poly(N-isopropylacrylamide)-b- Poly(L-Lysine Hydrochloride) and Poly(N-Isopropylacrylamide- co-Acrylamide)-b-Poly(L-Lysine Hydrochloride)

Materials (Basel). 2014 Jul 22;7(7):5305-5326. doi: 10.3390/ma7075305.

Authors

Milica Spasojević^{1

2}, Joop Vorenkamp³, Mark R P A C S Jansen⁴, Paul de Vos⁵, Arend Jan Schouten⁶

Affiliations

¹ Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands. m.spasojevic@umcg.nl.
² Department of Pathology and Medical Biology, Section of Immunoendocrinology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, EA11, 9700 RB Groningen, The Netherlands. m.spasojevic@umcg.nl.
³ Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands. e.j.vorenkamp@rug.nl.
⁴ Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands. m.r.p.a.c.s.jansen@rug.nl.
⁵ Department of Pathology and Medical Biology, Section of Immunoendocrinology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, EA11, 9700 RB Groningen, The Netherlands. p.de.vos@umcg.nl.
⁶ Department of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands. a.j.schouten@rug.nl.

Abstract

The synthesis of poly(N-isopropylacrylamide)-b-poly(L-lysine) and poly(N- isopropylacrylamide-co-acrylamide)-b-poly(L-lysine) copolymers was accomplished by combining atom transfer radical polymerization (ATRP) and ring opening polymerization (ROP). For this purpose, a di-functional initiator with protected amino group was successfully synthetized. The ATRP of N-isopropylacrylamide yielded narrowly dispersed polymers with consistent high yields (~80%). Lower yields (~50%) were observed when narrowly dispersed random copolymers of N-isopropylacrylamide and acrylamide where synthesized. Amino-terminated poly(N-isopropylacrylamide) and poly(N-isopropylacrylamide- co-acrylamide) were successfully used as macroinitiators for ROP of N₆-carbobenzoxy-L- lysine N-carboxyanhydride. The thermal behavior of the homopolymers and copolymers in aqueous solutions was studied by turbidimetry, dynamic light scattering (DLS) and proton nuclear magnetic resonance spectroscopy (¹H-NMR).

Keywords: ATRP; ROP; diblock copolymers; thermal behavior.