Probing the molecular interactions in the diffusion of water through epoxy and epoxy-bismaleimide networks

被引:78
作者
Musto, P
Ragosta, G
Scarinzi, G
Mascia, L
机构
[1] CNR, Inst Res & Technol Plast Mat, I-80072 Arco Felice Napoli, Italy
[2] Loughborough Univ Technol, Inst Polymer Technol & Mat Engn, Loughborough LE11 3TU, Leics, England
关键词
diffusion; thermosets; FTIR;
D O I
10.1002/polb.10147
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Fourier transform infrared spectroscopy in the near-infrared (NIR) frequency range was used to investigate the molecular interactions occurring between absorbed water molecules and networks based on a tetrafunctional epoxy resin. One of these networks was a typical formulation containing 4,4'-diamino diphenylsulfone as a hardener, and the other was a modified resin containing 4,4'-bismaleimide-diphenylmethane (BMI) as a coreactive monomer. Molecular spectroscopy analysis confirmed the existence of mobile water localized into network defects (microvoids) that did not interact with the networks and water molecules bound to the networks through hydrogen-bonding interactions. In the BMI-containing system, the fraction of bound water decreased significantly with respect to the unmodified epoxy resin. This was a relevant result because the bound water was primarily responsible for the plasticization of the network and for the consequent worsening of mechanical performance. Water diffusion was investigated with gravimetric sorption measurements and time-resolved Fourier transform NIR spectroscopy measurements. These showed that the presence of BMI decreased the water uptake at equilibrium, enhanced the diffusivity, and reduced the activation energy for diffusion, A dual-mode model for diffusion was found to be suitable for accurately describing the mass-transport process in both investigated systems. The results of the model simulations allowed us to estimate the ratio of free and bound water, which was in good agreement with that obtained from the spectroscopic analysis. (C) 2002 Wiley Periodicals, Inc.
引用
收藏
页码:922 / 938
页数:17
相关论文
共 35 条
[1]  
[Anonymous], ENCY POLYM SCI ENG
[2]   NEAR-INFRARED STUDIES OF STRUCTURE OF WATER .3. MIXED SOLVENT SYSTEMS [J].
CHOPPIN, GR ;
VIOLANTE, MR .
JOURNAL OF CHEMICAL PHYSICS, 1972, 56 (12) :5890-+
[3]   2-STATE THEORY OF STRUCTURE OF WATER [J].
DAVIS, CM ;
LITOVITZ, TA .
JOURNAL OF CHEMICAL PHYSICS, 1965, 42 (07) :2563-&
[4]  
DOMEIER LA, 1987, Patent No. 4654407
[5]  
Ellis B, 1993, CHEM TECHNOLOGY EPOX
[6]  
HERZBERG G, 1962, MOL SPECTRA STRUCTUR
[7]   DIFFUSION OF MOISTURE INTO 2-PHASE POLYMERS .2. STYRENATED POLYESTER RESINS [J].
JACOBS, PM ;
JONES, FR .
JOURNAL OF MATERIALS SCIENCE, 1989, 24 (07) :2343-2348
[8]   DIFFUSION OF MOISTURE INTO 2-PHASE POLYMERS .1. THE DEVELOPMENT OF AN ANALYTICAL MODEL AND ITS APPLICATION TO STYRENE ETHYLENE BUTYLENE STYRENE BLOCK COPOLYMER [J].
JACOBS, PM ;
JONES, FR .
JOURNAL OF MATERIALS SCIENCE, 1989, 24 (07) :2331-2336
[9]   NATURE OF THE WATER EPOXY INTERACTION [J].
JELINSKI, LW ;
DUMAIS, JJ ;
CHOLLI, AL ;
ELLIS, TS ;
KARASZ, FE .
MACROMOLECULES, 1985, 18 (06) :1091-1095
[10]  
KELL GS, 1972, WATER AQUEOUS SOLUTI