• Elastomers and Composites
• /
• v.51 no.3
• /
• pp.212-217
• /
• 2016

Influence of poly(ethylene-co-vinyl acetate) (EVA) types and cure systems on cure characteristics of foaming EVA compounds were investigated. Three kind EVAs with different VA contents were employed. Influence of triallyl cyanurate (TAC) and dicumylperoxide (DCP) content on the cure characteristics were examined. The minimum torque ($T_{min}$) and delta torque (${\Delta}T$) decreased as the VA content increased. The ${\Delta}T$ was increased by adding TAC and by increasing the DCP content. For the foaming EVA compounds without TAC, the cure times such as the minimum cure time ($t_{min}$), scorch time ($t_2$), and optimal cure time ($t_{90}$) did not show a specific trend according to the DCP contents. For the foaming EVA compounds containing TAC, the cure times decreased as the DCP content increased. From the experimental results, it was found that efficienct DCP/TAC ratio for improvement of the crosslink density was 1.1~2.0.

• Journal of the Semiconductor & Display Technology
• /
• v.19 no.1
• /
• pp.29-35
• /
• 2020

The cure characteristics of three kinds of naphthalene type epoxy resins(NET-OH, NET-MA, NET-Epoxy) with a 2-methyl imidazole(2MI) catalyst were investigated for preparing sheet epoxy molding compound(SEMC) for wafer level package(WLP) applications, comparing with diglycidyl ether of bisphenol-A(DGEBA) and 1,6-naphthalenediol diglycidyl ether(NE-16) epoxy resin. The cure kinetics of these systems were analyzed by differential scanning calorimetry with an isothermal approach, and the kinetic parameters of all systems were reported in generalized kinetic equations with diffusion effects. The NET-OH epoxy resin represented an n-th order cure mechanism as like NE-16 and DGEBA epoxy resins, however, the NET-MA and NET-Epoxy resins showed an autocatalytic cure mechanism. The NET-OH and NET-Epoxy resins showed higher cure conversion rates than DGEBA and NE-16 epoxy resins, however, the lowest cure conversion rates can be seen in the NET-MA epoxy resin. Although the NETEpoxy and NET-MA epoxy resins represented higher cure reaction conversions comparing with DGEBA and NE-16 resins, the NET-OH showed the lowest cure reaction conversions. It can be figured out by kinetic parameter analysis that the lowest cure conversion rates of the NET-MA epoxy resin are caused by lower collision frequency factor, and the lowest cure reaction conversions of the NET-OH are due to the earlier network structures formation according to lowest critical cure conversion.

• Macromolecular Research
• /
• v.9 no.3
• /
• pp.157-163
• /
• 2001

The influences of carbon black loading and cure type on the cure characteristics including kinetics and dynamic mechanical properties were investigated for a styrene-butadiene rubber (SBR). The rate constants of accelerated sulfur vulcanization reaction at three different temperatures were determined using a cure rheometer, and they were compared with those from the direct measurement of sulfur concentration. The strain softening behavior under dynamic deformation, known as the Payne effect was also discussed depending on the carbon black loading and cure type.

• Elastomers and Composites
• /
• v.50 no.2
• /
• pp.87-91
• /
• 2015

Cure characteristics of non-oil-extended solution SBR (S-SBR_NO) and oil-extended solution SBR (S-SBR_ EO) compounds reinforced with silica/carbon black were investigated. Minimum and maximum torques of S-SBR_ EO compounds were much smaller than those of S-SBR_NO ones. Delta torques of S-SBR_NO compounds were greater than those of S-SBR_EO ones, and that of S-SBR_NO compound increased with increase in the 1,2-unit content. Optimum cure time ($t_{90}$) of S-SBR compound decreased with increase in the 1,4-unit content, whereas it increased with increase in the 1,2-unit content. Cure rate index of S-SBR compound increased with increase in the 1,4-unit content, whereas it decreased with increase in the 1,2-unit content. Comparing cure characteristics of S-SBR_NO and S-SBR_EO compounds with the same 1,2-unit content, $t_{90}$s of S-SBR_EO compounds were longer than those of S-SBR_NO ones and cure rate indices of S-SBR_EO compounds were smaller than those of S-SBR_NO ones.

• Journal of Korean Medical classics
• /
• v.28 no.3
• /
• pp.45-65
• /
• 2015

Objectives : Holsaye, the doctor responsible for the King's health, explained about ways to comfort body and mind and not get diseases for long life ("Yangsaeng") and about food in Eumsunjungyp which was a dietary cure book compiled and published in the Yuan Dynasty. This study examined about what the definition of Yangsaeng, introduced by a doctor from a different country, and the characteristics of the ways in treating the sick with Yangsaeng and food in the Yuan dynasty. Methods : This study used Eumsunjungyo from the China Chinese Medicine Publisher as its method. It analyzed the organization and the characteristics of the contents of Eumsunjungyo, and compared with Korea's first dietary cure book Singnyochanyo("食療纂要"). Results : Eumsunjungyo is a dietary cure book written by a doctor in the Yuan Dynasty. It suggested different ways of Yangsaeng according to specific patients and purposes, and explained the importance of food. Singnyochanyo is a dietary cure book written by a doctor in the Joseon Dynasty. It suggested ways to cure each of categorized diseases using foods. Conclusions : Eumsunjungyo is a dietary cure book written in 1330 to which the unique food culture of the people in other countries applied. Singnyochanyo written in 1460 is a kind of dietary cure book as well, but it categorized foods for each disease and revealed characteristics as an emergency care. However, Eumsunjungyo stressed health management through Yangsaeng and foods throughout the whole life.

• Composites Research
• /
• v.14 no.1
• /
• pp.30-38
• /
• 2001

As fiber reinforced composite materials are widely used in aircraft, space structures and robot arms, the on-line cure monitoring during the cure process of the composite materials has become an important research area for the better quality and productivity. In this paper, the dielectric circuit of the Wheatstone bridge type for measuring the dissipation factor during cure of thermsetting resin matrix composite materials was designed and manufactured. Also, the dielectric sensor for the cure monitoring of high temperature cure composites was developed and tested. The residual thermal stresses of the dielectric sensor during high temperature cure were analyzed by the finite element method and its dielectric characteristics at high temperature cure were analyzed by the finite element method and its dielectric characteristics at high temperature were evaluated. The on-line cure monitoring of the BMI(Bismaleimide) resin was performed using the developed Wheatstone bridge type circuit and the high-temperature dielectric sensor.

• Macromolecular Research
• /
• v.17 no.8
• /
• pp.585-590
• /
• 2009

The cure behaviors, dielectric characteristics and fracture toughness of diglycidylether of bisphenol-A (DGEBA)/poly(ethylene terephthalate) (PET) blend system were investigated. The degree of conversion for the DGEBA/PET blend system was measured using Fourier transform infrared (FTIR) spectroscopy. The cure kinetics were investigated by measuring the cure activation energies ($E_a$) with dynamic differential scanning calorimetry (DSC). The dielectric characteristic was examined by dielectric analysis (DEA). The mechanical properties were investigated by measuring the critical stress intensity factor ($K_{IC}$), critical strain energy release rate ($G_{IC}$), and impact strength test. As a result, DGEBAIPET was successfully blended. The Ea of the blend system was increased with increasing PET content to a maximum at 10 phr PET. The dielectric constant was decreased with increasing PET content. The mechanical properties of the blend system were also superior to those of the neat DGEBA. These results were attributed to the increased cross-linking density of the blend system, resulting from the interaction between the epoxy group of DGEBA and the carboxyl group of PET.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2000.11a
• /
• pp.38-41
• /
• 2000

High temperature cure characteristics of polyester resin systems were investigated by isothermal and dynamic differential scanning calorimetries. During isothermal scanning, the experimental procedure was modified to reduce the initial Boss of heat. no kinetic equation from the isothermal experiment was compared with that from the dynamic experiment.

• Elastomers and Composites
• /
• v.35 no.3
• /
• pp.215-226
• /
• 2000

Cure characteristics of carbon black-filled rubber compounds with different rubber composition were studied using a rheometer. The carbon black-filled rubber compounds with single, binary, and ternary rubber compositions of natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene rubber (BR) were used. Delta-torques of the NR/BR- and SBR/BR-based compounds with a high BR content were higher than those of the single rubber-based compounds. For ternary rubber-based compounds, the delta-torques of the compounds were lower when the difference in the rubber content ratios was small than when it was big. Scorch and optimum cure times of the rubber compounds became shorter by increasing the content of NR in the compounds while those became longer by increasing the SBR content. Cure rates of the rubber compounds increased with a decrease of the SBR content in the rubber compounds. Reversion ratios decreased with an increase of the SBR content in the rubber compounds.

• Elastomers and Composites
• /
• v.47 no.3
• /
• pp.254-258
• /
• 2012

Material characteristics and the prediction of life time of polyacrylic rubber (ACM) for automotive engine gasket were studied. Two kinds of ACM rubber compounds, having chlorine cure-site and carboxyl cure-site, were made with optimum formulations and the properties of each materials were examined. As a test results for the thermal properties and compression set, which are very important in the application for the automotive engine gasket, the compound using ACM with carboxyl cure-site was evaluated as having a better characteristics than that of ACM with chlorine cure-site. Arrhenius relationship based on time-temperature superposition principle (TTSP) was obtained through the accelerated heat aging test to predict the useful life-time for the compound using ACM with carboxyl cure-site.