Current time in Korea 16:01 Oct 20 (Fri) Year 2017 KCS KCS Publications
KCS Publications
My Journal Log In Register
HOME > Search > Browsing(BKCS) > Archives

Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 35, Number 2
BKCSDE 35(2)
February 20, 2014 

 
Title
Well-Defined Thermoresponsive Copolymers with Tunable LCST and UCST in Water
Author
Seo-Hyun Jung, Hyung-il Lee*
Keywords
ATRP, UCST, LCST, PDMAEMA, Zwitterions
Abstract
A thermoresponsive polymer, poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA), was successfully synthesized by atom transfer radical polymerization (ATRP). Different amounts of 1,3-propanesultone were used as quaternization agent to transit the PDMAEMA into partially modified poly(zwitterions), resulting in p[DMAEMA-co-3-dimethyl(methacryloyloxyethyl)ammonium propanesulfonate] (PDMAEMA-co-PDMAPS). Molecular weight, molecular weight distribution, and degree of quarternization were determined by gel permeation chromatography (GPC) and 1H NMR spectroscopy. The transmission spectra of the 1.0 wt % aqueous solutions of the resulting polymers at 650 nm were measured as a function of temperature. Results showed that the lower critical solution temperature (LCST) and the upper critical solution temperature (UCST) could be easily controlled by the different composition of dimethylamino and zwitterion groups. The effect of partial quaternization on thermoresponsive properties was also studied by dynamic light scattering (DLS) with the same aqueous concentration (1.0 wt %) as employed for turbidimetry studies. The LCST and UCST values measured by DLS correlated well with those determined by turbidimetry.
Page
501 - 504
Full Text
PDF