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Influence of ethyl methacrylate content on the volume‐phase transition of temperature‐sensitive poly[( N ‐isopropylacrylamide)‐ co ‐(ethyl methacrylate)] microgels
Author(s) -
Ma Xiaomei,
Huang Xiaobin,
Zhu Lu,
Zhao Xi'an,
Tang Xiaozhen
Publication year - 2005
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.1619
Subject(s) - dynamic light scattering , methacrylate , dispersity , differential scanning calorimetry , poly(n isopropylacrylamide) , materials science , polymer chemistry , polymerization , copolymer , chemical engineering , polymer , nanoparticle , nanotechnology , thermodynamics , composite material , physics , engineering
A novel series of temperature‐sensitive poly[( N ‐isopropylacrylamide)‐ co ‐(ethyl methacrylate)] (p(NIPAM‐ co ‐EMA)) microgels was prepared by the surfactant‐free radical polymerization of N ‐isopropylacrylamide (NIPAM) with ethyl methacrylate (EMA). The shape, size dispersity and volume‐phase transition behavior of the microgels were investigated by transmission electron microscopy (TEM), ultraviolet–visible (UV–Vis) spectroscopy, dynamic light scattering (DLS) and differential scanning calorimetry (DSC). The transmission electron micrographs and DLS results showed that microgels with narrow distributions were prepared. It was shown from UV–Vis, DLS and DSC measurements that the volume‐phase transition temperature (VPTT) of the p(NIPAM‐ co ‐EMA) microgels decreased with increasing incorporation of EMA, but the temperature‐sensitivity was impaired when more EMA was incorporated, causing the volume‐phase transition of the microgels to become more continuous. It is noteworthy that incorporation of moderate amounts of EMA could not only lower the VPTT but also enhance the temperature‐sensitivity of the microgels. The reason for this phenomenon could be attributed to changes in the complicated interactions between the various molecules. Copyright © 2004 Society of Chemical Industry