Browsing by Author "JENG, KT"

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COMPATIBLE SIMULTANEOUS INTERPENETRATING POLYMER NETWORKS BASED ON EPOXY-RESIN AND POLY(POLY(ETHYLENE GLYCOL)MALEATE)
(1993)
LIN, MS
;
JENG, KT
;
YANG, T
;
交大名義發表
;
應用化學系
Poly(poly(ethylene glycol)maleate) (PPEGMA) was synthesized from poly(ethylene glycol) of molecular weight 200 with maleic anhydride in a molar ratio of 1:1. PPEGMA was then blended with diglycidyl ether of bisphenol A (DGEBA) in various ratios. The formation of hydrogen bonds between PPEGMA and DGEBA was investigated with FTi.r. These blends were then cured with benzoyl peroxide and m-xylenediamine simultaneously to obtain simultaneous interpenetrating polymer networks (SINs). Cure behaviours via exothermic peaks were recorded by dynamic d.s.c. The SINs thus obtained were characterized with rheometric dynamic spectroscopy (r.d.s.) and d.s.c. to check the compatibility of the two constituent networks. Gel fractions were measured with a Soxhlet extractor using acetone as solvent. Hydrogen bonding in the PPEGMA/DGEBA blend was evidenced from the v(C=O) shift to lower wavenumber. During SIN formation, dynamic d.s.c. showed a shift of the exothermic peak to a higher and broader temperature range, indicating a network interlocking effect which was overcome by higher temperature. Full compatibility of PPEGMA/DGEBA SINs was found for all compositions. The compatibility between PPEGMA and DGEBA was supported from the inner shifts of a single damping peak in r.d.s. and a single glass transition in d.s.c. for each of the SINs.
OPTICALLY CLEAR SIMULTANEOUS INTERPENETRATING POLYMER NETWORKS BASED ON POLY(ETHYLENE GLYCOL) DIACRYLATE AND EPOXY .1. PREPARATION AND CHARACTERIZATION
(1992-08-01)
LIN, MS
;
JENG, KT
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
Poly(ethylene glycol) diacrylate was synthesized from poly(ethylene glycol) of molecular weight 600 with acryloyl chloride in a molar ratio of 1 : 2. Poly (ethylene glycol) diacrylate (PEGDA) was then blended with diglycidyl ether of bisphenol A (DGEBA) in various ratios, followed by curing with 2,2'-azobisisobutyronitrile (AIBN) and isophronediamine (IPDA) simultaneously. Viscosity changes before and during IPN formation were examined with a Brookfield viscometer. Formation of H-bonding and functional group changes were investigated with FTIR. Exothermic curing thermograms were recorded with dynamic DSC. Optically clear IPNs thus obtained were characterized with rheometric dynamic spectroscopy (RDS) and scanning electron microscopy (SEM) to check possible compatibility of the two networks. Experimental results revealed that during IPN formation hydrogen bonds between PEGDA and DGEBA and interlock of networks had profound effect on viscosity change and pot-life. Complete compatibility of the IPNs was found as DGEBA content was higher than 50% by weight. The compatibility between PEGDA and DGEBA networks was evidenced from inner shift of a single damping peak in RDS. In the meantime, SEM micrographs confirmed the coincidence with the result of RDS
OPTICALLY CLEAR SIMULTANEOUS INTERPENETRATING POLYMER NETWORKS BASED ON POLY(ETHYLENE GLYCOL)DIACRYLATE AND EPOXY .2. KINETIC-STUDY
(1993-12-01)
LIN, MS
;
JENG, KT
;
HUANG, KY
;
SHIH, YF
;
交大名義發表
Simultaneous interpenetrating polymer networks (SINs) based on diglycidyl ether of bisphenol A (DGEBA) and poly(ethylene glycol) diacrylate (PEGDA) in weight ratios of 100/0, 50/50, and 0/ 100 were blended and cured simultaneously by using benzoyl peroxide (BPO) and m-xylenediamine (MXDA) as curing agents. A kinetic study during SIN formation was carried out at 45, 55, 63, and 70-degrees-C. Concentration changes for both the epoxide and C = C bond were monitored with FTIR. A rate expression for DGEBA cure kinetics was established with a model reaction of phenyl glycidyl ether (PGE) and benzylamine. Experimental results revealed that lower rate constants and higher activation energy for the SIN were found, compared with those for the constituent DGEBA and PEGDA network formation. A model of network interlock was proposed to account for this phenomenon. During simultaneous cure of DGEBA and PEGDA, the interlock (mutual entanglement) between DGEBA and PEGDA networks provided a sterically hindered environment, which subsequently increased the activation energy and reduced cure rates for both DGEBA and PEGDA. (C) 1993 John Wiley & Sons, Inc.