THERMODYNAMIC ANALYSIS OF SCANNING CALORIMETRIC TRANSITIONS OBSERVED FOR DILUTE AQUEOUS-SOLUTIONS OF ABA BLOCK COPOLYMERS

被引:29
作者
MITCHARD, NM [1 ]
BEEZER, AE [1 ]
MITCHELL, JC [1 ]
ARMSTRONG, JK [1 ]
CHOWDHRY, BZ [1 ]
LEHARNE, S [1 ]
BUCKTON, G [1 ]
机构
[1] UNIV KENT, CHEM LAB, CANTERBURY CT2 7NH, KENT, ENGLAND
关键词
D O I
10.1021/j100202a079
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Dilute aqueous solutions of a series of poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) block polymers have been shown to undergo phase transitions. A high-sensitivity differential scanning calorimetric (HSDSC) study of these block copolymers bas enabled the thermodynamic parameters for the phase transitions to be obtained. The thermodynamic parameters are all dependent on poly(oxypropylene) content of the polymer and riot on poly(oxyethylene) content or total polymer molecular mass. The importance of the poly(oxypropylene) in determining the aqueous solution phase properties of these polymers is further emphasized by the positive value for the heat capacity change from pre- to postphase transition. A positive heat capacity change is characteristic of "melting" of water ordered by exposed nonpolar groups. The work reported in this paper shows that the thermodynamic parameters describing the polymer phase transitions can be derived from basic thermodynamic principles and from consideration of the poly(oxypropylene) content. The theoretical analysis described in this paper also predicts that these polymers should undergo a second phase transition at high temperature and indeed these transitions have been detected by HSDSC.
引用
收藏
页码:9507 / 9512
页数:6
相关论文
共 13 条
[1]  
BEEZER AE, 1991, J CHEM RES-S, P254
[2]  
FRANKS HS, 1945, J PHYS CHEM-US, V30, P507
[3]   THE BEHAVIOR OF PLURONIC-F127 IN AQUEOUS-SOLUTION STUDIED USING FLUORESCENT-PROBES [J].
GILBERT, JC ;
WASHINGTON, C ;
DAVIES, MC ;
HADGRAFT, J .
INTERNATIONAL JOURNAL OF PHARMACEUTICS, 1987, 40 (1-2) :93-99
[4]   AQUEOUS SOLUBILITY AND GAS-HYDRATES - METHANE-WATER SYSTEM [J].
GLEW, DN .
JOURNAL OF PHYSICAL CHEMISTRY, 1962, 66 (04) :605-&
[5]  
IRWIN JJ, 1992, UNPUB J PHYS CHEM
[6]   POLYOXYETHYLENE POLYOXYPROPYLENE BLOCK COPOLYMERS - A NOVEL PHASE-TRANSITION IN AQUEOUS-SOLUTIONS OF PLURONIC-F87 (POLOXAMER-237) [J].
MITCHARD, N ;
BEEZER, A ;
REES, N ;
MITCHELL, J ;
LEHARNE, S ;
CHOWDHRY, B ;
BUCKTON, G .
JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1990, (13) :900-901
[7]  
MITCHARD NM, 1990, THESIS U LONDON
[8]   STRUCTURE OF WATER AND HYDROPHOBIC BONDING IN PROTEINS .1. A MODEL FOR THERMODYNAMIC PROPERTIES OF LIQUID WATER [J].
NEMETHY, G ;
SCHERAGA, HA .
JOURNAL OF CHEMICAL PHYSICS, 1962, 36 (12) :3382-&
[9]  
PRIVALOV PL, 1988, ADV PROTEIN CHEM, V39, P191
[10]   THERMODYNAMIC PROBLEMS OF PROTEIN-STRUCTURE [J].
PRIVALOV, PL .
ANNUAL REVIEW OF BIOPHYSICS AND BIOPHYSICAL CHEMISTRY, 1989, 18 :47-69