<link rel="stylesheet" href="styles.cf390c6bfbe7555f.css">

學術出版;;Publications

Permanent URI for this communityhdl:11536/1

收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

Browse

Filters

1996 - 199942000 - 20102

Settings

🏛️國立陽明交通大學機構典藏

Access type: Metadata onlySubject: search.filters.subject.epoxy

Search Results

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item type:Item,
    Mechanism of transesterification and cyclization of epoxy-polycarbonate blends catalyzed by quarternary ammonium salt
    (1996-11-30)
    Li, MS
    ;
    Ma, CCM
    ;
    Lu, MS
    ;
    Lin, ML
    ;
    Chang, FC
    The reaction of oxirane with carbonate using quarternary ammonium salts as catalyst has been studied. Curing is caused by the transesterification reaction of the oxirane cycle with the carbonate group that proceeds by an ''insertion'' mechanism in the stoichiometric system. The ratio of the reactants is two oxirane groups to one carbonate group. In the nonstoichiometric system, the epoxide content is more than the stoichiometric quantity required. A cyclization reaction is followed by the transesterification reaction. To identify the finished products, a model reaction was proposed using diphenyl carbonate and phenyl glycidyl ether which results in the formation of 4-phenoxymethyl-1,3-dioxolane-2-one (PMD). The mechanism of forming the cyclic structure is assumed to proceed through the chain scission of the network in which the molecular chain crosslinked with carbonate group by a transesterification reaction. (C) 1996 John Wiley & Sons,Inc.
  • Thumbnail Image
    Item type:Item,
    The epoxy-polycarbonate blends cured with aliphatic amine .2. Thermal and mechanical properties mechanisms
    (1997-09-30)
    Lin, ML
    ;
    Chang, KH
    ;
    Chang, FC
    ;
    Li, MS
    ;
    Ma, CCM
    The transamidation reaction converts the carbonate and amine into N-aliphatic aromatic carbamate and urea, causing the equivalent of oxirane and amine nonstoichiometric in the primary cure stage. After postcure, the substitution reaction takes place and results in a more tightly crosslinked structure. Such a higher crosslinking density is responsible for higher T-g, tensile strength, and tensile modulus in the postcure stage than that in the primary and secondary cure stages. This trend is more pronounced in those PC-epoxy blends containing higher molecular weight aliphatic amine or a higher content of PC. This phenomenon is due to the difference in the fraction of amino group of aliphatic amine consumed in the transamidation. PC-epoxy/aliphatic amine blends show minor improvement in the high strain rate Izod impact tests, while toughness improvement for some blends is substantial at low strain rate tensile tests. (C) 1997 John Wiley & Sons, Inc.
  • Thumbnail Image
    Item type:Item,
    The epoxy-polycarbonate blends cured with aliphatic amine .1. Mechanism and kinetics
    (1997-09-30)
    Lin, ML
    ;
    Chang, KH
    ;
    Chang, FC
    ;
    Li, MS
    ;
    Ma, CCM
    Reaction mechanism of the PC-epoxy blends cured by aliphatic amine has been investigated by varying PC contents in the blends. The transamidation reaction tends to convert nearly all the carbonates into N-aliphatic aromatic carbamates even at ambient temperature before normal curing. The remaining amine proceeds the normal curing with epoxy at a higher temperature (80 degrees C). For the PC-epoxy/aliphatic amine blend containing 6 wt % PC, the yielded N-aliphatic aromatic carbamate further reacts with amine to produce the urea structure. The urea undergoes substitution reaction with the hydroxyl formed from the normal curing to give the N-aliphatic aliphatic carbamate. For the blend containing 12 wt % PC, the N-aliphatic aromatic carbamate converts into the N-aliphatic aliphatic carbamate via two different routes. For the blend containing lower molecular weight of the aliphatic amine, the N-aliphatic aromatic carbamate reacts with hydroxyl to form the N-aliphatic aliphatic carbamate directly. For the blend containing higher molecular weight of aliphatic amine, the N-aliphatic aromatic carbamate decomposes into the aliphatic isocyanate accelerated by the presence of the residual oxirane. The isocyanate formed then reacts with hydroxyl to yield the N-aliphatic aliphatic carbamate. The activation energy (E-alpha) and preexponential factor (A) of the PC-epoxy/POPDA blends decrease with the increase of the PC content. Kinetic study by thermal analysis by the method of autocatalyzed model is able to correctly predict oxirane conversion vs. time relationship for the neat epoxy/aliphatic amine and the PC-epoxy/aromatic amine systems because the dominant reaction is the normal curing reaction between amine and oxirane. The model fails to predict the PC-epoxy/aliphatic amine system because the system is complicated by several other reactions besides the normal curing reaction. (C) 1997 John Wiley & Sons, Inc.
  • Thumbnail Image
    Item type:Item,
    Transesterification and cyclization of polycarbonate-epoxy blends cured with anhydride
    (1996-08-01)
    Li, MS
    ;
    Su, YF
    ;
    Ma, CCM
    ;
    Chen, JL
    ;
    Lu, MS
    Infrared spectra have been investigated to study the curing mechanisms of polycarbonate-epoxy blends using anhydride as a hardener catalysed by tertiary amine. Due to a significant difference in the reaction, curing reactions of the system can be considered as two sequential stages: (1) an anionic alternating copolymerization of cyclic anhydride and epoxy resin, and (2) a homopolymerization of oxirane initiated by a quaternary ammonium salt zwitter ion. The transesterification/cyclization of carbonate groups proceeds in the later stage if the oxirane is still available. Degrees of transesterification/cyclization and homopolymerization are higher when a higher epoxy/anhydride ratio is used. This study positively confirms the mechanism of transesterification/cyclization proceeding through a zwitter ion. The zwitter ion is formed from epoxide and tertiary amine, which attacks the carbonate group. Copyright (C) 1996 Elsevier Science Ltd.
  • Thumbnail Image
    Item type:Item,
    Synthesis and physical properties of linear and branch phenoxies
    (2001-12-01)
    Chen, JR
    ;
    Li, YS
    ;
    Chang, FC
    ;
    應用化學系
    ;
    Department of Applied Chemistry
    Linear and branch phenoxies have been synthesized by reacting difunctional epoxy and diphenol or triphenol monomer, using phosphonium salt as the catalyst. The reaction kinetics is analyzed by the ASTM E 698 method, which is suitable for a first order reaction system. The bulky structure of the bisphenol Z moiety retards the reaction; therefore, the reaction temperature required is higher- at 200 degreesC, compared to 190 degreesC for the bisphenol A based system. The introduction of a branch structure increases both molecular weight and the polydispersity of the phenoxy. A slightly branched structure tends to increase the distance between the polymer chains and results in a lower shear viscosity for easier processing. A higher branch results in light crosslinking and decreases the mobility of the polymer. The branch structure has a negligible effect on its glass transition temperature because the average distance between branches is substantially longer than the critical mainchain length for T-1's Brownian motion. The 100/1 (bisphenol/ trisphenol) system has the lowest viscosity, but its mechanical properties and the gas permeation properties are poorer than those of the others. The bisphenol Z based phenoxy shows superior mechanical properties, higher T-g, lower coefficient of thermal expansion, and lower gas permeation properties than the corresponding bisphenol A based phenoxy because of the steric hindrance structure of the bisphenol Z moiety.
  • Thumbnail Image
    Item type:Item,
    Influence of Sulfonationity of Epoxy-Based Semi-Interpenetrating Polymer Networks of Sulfonated Polyimides as Proton Exchange Membranes on the Performance of Fuel Cell Application
    (2010-04-01)
    Wang, Yen-Zen
    ;
    Ho, Ko-Shan
    ;
    Wu, Shinn-Dar
    ;
    Hsieh, Kuo-Huang
    ;
    Lee, Chi-Hung
    A novel epoxy-based semi-interpenetrating polymer networks membrane (SPIX-EP40) as the proton exchange membrane was prepared by a flexible epoxy network with sulfonated polyimide. A series of sulfonated polyamic acid (SPAA) were prepared from 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2-benzidinedisulfonic acid (BDSA) and non-sulfonated diamines, such as 4,4'-diaminodiphenyl sulfone. Solid-state (13)C nuclear magnetic resonance spectra and Fourier transform infrared spectroscopy were used to verify the synchronization of the imidization of SPAA and the crosslinking reactions of epoxy. The sulfonationity of the copolymers was regulated through a variation in the molar ratio of BDSA to diamine. These membranes owned a good thermal stability and exhibited high proton conductivity that was measured as a function of temperature. The resulting SPI0.7-EP40 and SPI0.8-EP40, at 100% relative humidity, displayed proton conductivities higher than those of Nafion (R) 117. The membranes displayed higher conductivities than Nafion (R) membranes because of owning higher activational energies and higher ion exchange capacities. An isotropic swelling phenomenon in water was found for the membrane. From the results of water uptake and the microstructure analyses using transmission electron microscopy (TEM) on different sulfonated levels, it was found that the number of water clusters in SPIX-EP40 membranes increased as the increasing water uptake and the size of water cluster were changed with the sulfonation levels. TEM confirmed the widespread and well-connected hydrophilic domains, demonstrating the presence of the favorable proton-transporting performances of the SPIX-EP40 membrane. [DOI: 10.1115/1.3177383]