Temperature and Recognition Dual Responsive Poly(N-Isopropylacrylamide) and Poly(N,N-Dimethylacrylamide) with Adamantyl Side Group

Qiujing Dong; Chunhua Luo; Na Li; Jiaxiang Chi; Qingqing Zhang

doi:10.3390/ma11040473

Temperature and Recognition Dual Responsive Poly(N-Isopropylacrylamide) and Poly(N,N-Dimethylacrylamide) with Adamantyl Side Group

Materials (Basel). 2018 Mar 22;11(4):473. doi: 10.3390/ma11040473.

Authors

Qiujing Dong^{1

2}, Chunhua Luo^{3

4}, Na Li⁵, Jiaxiang Chi⁶, Qingqing Zhang⁷

Affiliations

¹ School of Chemistry and Materials Engineering, Fuyang Normal University, Fuyang 236037, China. dongqj1980@163.com.
² Anhui Provincial Key Laboratory for Degradation and Monitoring of the Pollution of the Environment, Fuyang 236037, China. dongqj1980@163.com.
³ School of Chemistry and Materials Engineering, Fuyang Normal University, Fuyang 236037, China. ch-luo@fync.edu.cn.
⁴ Anhui Provincial Key Laboratory for Degradation and Monitoring of the Pollution of the Environment, Fuyang 236037, China. ch-luo@fync.edu.cn.
⁵ School of Chemistry and Materials Engineering, Fuyang Normal University, Fuyang 236037, China. Lina041722@163.com.
⁶ School of Chemistry and Materials Engineering, Fuyang Normal University, Fuyang 236037, China. Chijx961103@163.com.
⁷ School of Chemistry and Materials Engineering, Fuyang Normal University, Fuyang 236037, China. Zhangqing24958@163.com.

Abstract

A series of copolymers with an adamantyl side group (poly(NIPAM-co-AdMA) and poly(DMAM-co-AdMA)) were prepared by radical copolymerization of N-isopropylacrylamide (NIPAM) and N,N-dimethylacrylamide (DMAM) with a 2-methyl-2-adamantylmethacrylate (AdMA) monomer. The structure and composition of the as-synthesized copolymers were characterized by Fourier transform infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (¹H NMR) spectroscopy, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and elemental analysis. Temperature and recognition dual responsivity of the copolymers was investigated by cloud point (T_cp) and dynamic light scattering (DLS), respectively. The results show that the as-synthesized copolymers are a kind of temperature-responsive polymer with a lower critical solution temperature (LCST). T_cp was approximately consistent with the critical temperature of intermolecular copolymer association (T_ass) from DLS. For these copolymers, T_cp decreases with increasing content of AdMA unit in the copolymers. After the addition of β-cyclodextrins (β-CD), T_cp increases, and the increment of T_cp values gradually became large with increasing content of AdMA in the copolymers. It is host-guest molecular recognition of β-CD and adamantyl groups that endows the as-synthesized copolymers with recognition-tunable thermosensitivity.

Keywords: adamntyl groups; molecular recognition; poly(N,N-dimethylacrylamide); poly(N-isopropylacrylamide); temperature responsive; β-cyclodextrins.