• Korean Chemical Engineering Research
• /
• v.50 no.3
• /
• pp.588-593
• /
• 2012

Compatibility of unsaturated polyester (UP) and low profile agent (LPA) of polystyrene (PS) have been investigated under various mixing conditions such as the ratio of UP and LPA, mixing time, mixing temperature, and input amount of 2nd UP. It was possible to obtain mixture with small particle size and low phase separation in condition of 35 g of LPA, 25 g of 1st UP input, 5 min of mixing time, 1700 rpm of mixing speed, and 45 g of 2nd UP input. It was found that compatibility of UP and LPA was very sensitive to mixing conditions. In addition, molded sample using sheet molding compound prepared by stable mixing condition appeared good properties such as low water adsorption, low shrinkage, and high gloss.

• Fire Science and Engineering
• /
• v.12 no.4
• /
• pp.51-57
• /
• 1998

The thermal behavior and the flammability characteristics of four different unsaturated polyester resins were studied by performing a series of thermal analysis experiments and laboratory scale fire tests. The results of TGA and DSC reveals that the vinylester type resins have superior thermal performances when compared to the isophthalic type resins. The vinylester type resins formed a network shaped char surface after the thermal decomposition up to 55$0^{\circ}C$. Consequently, the vinylester type resings have shown lower value of burning rate than that of iso type resins. Due to the high level of flammability and toxic smoke emission, the appropriate flame retardant system should be applied to the unsaturated polyester resings.

• Journal of the Korea Concrete Institute
• /
• v.19 no.2
• /
• pp.163-169
• /
• 2007

This study is focused on the proper mixture design of materials for the porous concrete with unsaturated polyester resin. The materials used in the mixture include the single-grade aggregates, unsaturated polyester resin as binder, and calcium carbonate as a filler. An experimental procedure has been carried out to select the best combination of the materials that satisfy both the required permeability and compressive strength. Various kinds of gravel size, the ratio of binder, and F/B ratios are tried to get proper mixture, and the permeability coefficient and compressive strength have been measured to find out the best combination of materials based on the proper Korean Standards. A promix design satisfied the standards of rainfall runoff reduction system with $3.5{\times}10^{-1}$ (cm/sec) of permeability, 34 % of porosity, 11 MPa of compressive strength can be obtained.

• Fire Science and Engineering
• /
• v.12 no.4
• /
• pp.41-49
• /
• 1998

In this study, the thermal improvement of an isophthalic acid polyester resin by the incorporation of flame retardants has been investigated. Aluminium hydroxide, antimony oxide and alumina powder were used to formulate the flame retardant systems. The improvement of an isophthalic resin by incorporating aluminium hydroxide is dramatic(burning rate and smoke emission are reduced), although the mechanical property is decreased significantly. The addition of small amount(2.5 phr) of antimony oxide produces high char yield(31%) which acts as a protective layer on the surface of the resin.

• Magazine of the Korea Concrete Institute
• /
• v.5 no.4
• /
• pp.156-166
• /
• 1993

The results of an experimental study on the manufacture and the mechanical properties of steel fiber reinforced polyester resin composites utilizing industrial waste products(fly ash) are presented in this paper. The composites using steel fiber, fly ash, unsaturated polyester resin, styrene monomer, catalyst (cobalt octate) and accelerator(methyl ethyl ketone peroxide), fine and coarse aggreates were prepared using various mixing conditions. As the test results show. the mechanical and physical properties, such as the compressive, tensile and flexural strengths, and the setting shrinkage of fly ash$\cdot$polyester resin composites were improved considerably by increasing the fly ash-binder ratio. And the workability of steel fiber reinforced fly ash$\cdot$polyester resin composites was reduced with increasing the fly ash-binder ratio and steel fiber content. Also, the compressive, flexural strength and toughness of the composites were remarkably increased by increasing steel fiber content.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.4 no.2 s.13
• /
• pp.29-34
• /
• 2004

The time to ignition, heat release rate characteristics, and carbon monoxide yield of fiber reinforced and sandwich phenol resin were investigated with cone calorimeter. The fire characteristics of unsaturated polyester, mostly being applied to the existing passenger train, and phenolic resin were compared. DSC & TGA was used to monitor the degree of thermal decomposition and weight loss for the phenolic resin. According to the cone calorimeter data, the time to ignition was shorter, heat release rate, and CO yield was higher as the external heat flux increased. Under the same heat flux, the time to ignition of sandwich type phenolic resin was shorter than that of laminated. The result of comparison between unsaturated polyester and phenolic resin was that phenolic resin was shown to have better fire resistance than unsaturated polyester.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.445-448
• /
• 2008

The unsaturated polyester(UP) and epoxy resin have a superior material properties and a chemical resistance using sewerage pipes rehabilitation. However, UP and epoxy have not a low temperatures harding, the requirement $8{\sim}11$ hours long times harding and heating system used by reinforcement liner. This study is to evaluate the effects of low temperature harding properties methyl methacrylate(MMA) monomer using expanded polystyrene(EPS) and UP in addition of initiator and promoters. From the test result, viscosity tends to increase with increasing EPS and UP contents. However, harding time change of the MMA resins which it follows in addition of the initiator and promoter.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.929-932
• /
• 2008

The unsaturated polyester(UP) and epoxy resin have a superior material properties and a chemical resistance using sewerage pipes rehabilitation. However, UP and epoxy have not a low temperatures harding, the requirement $8{\sim}11$ hours long times harding and heating system used by reinforcement liner. This study is to evaluate the effects of low temperature harding properties methyl methacrylate(MMA) monomer using expanded polystyrene(EPS) in addition of initiator and promoters. From the test result, viscosity tends to increase with increasing EPS contents. However, harding time change of the MMA resins which it follows in addition of the initiator and promoter.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2003.05a
• /
• pp.271-273
• /
• 2003

선박용 폐 FRP의 재활용 공정은 층 분리된 시편을 제조한 후, 촉매인 NaOH를 0.08이상, 용매인 PG를 6.0(폐 FRP 시편 무게당)이상 사용하여 분해하였고, 최적 반응시간은 5시간, 반응온도는 $250^{\circ}C$였다. 분해액에서 60 %의 PG를 분리한 잔여액을 사용하여도 재생 불포화 폴리에스터 수지를 합성할 수 있었으며, 분해공정에서 배출된 폐 유리섬유는 재생수지에 혼합 사용할 수 있었다.

• Polymer(Korea)
• /
• v.27 no.2
• /
• pp.120-128
• /
• 2003

The effects of catalyst, accelerator and blend composition on the cure behavior of unsaturated polyester resin (UPE), vinyl ester resin (VE) and their blends were studied using differential scanning calorimetry(DSC). The DSC thermograms strongly depend on each variable. The result shows that the small exothermic peak at 115$^{\circ}C$ is due mainly to the UPE component in the UPE/VE blends and the large one at 134~138 $^{\circ}C$ is due mainly to the VE component. The results also indicate that the change of the DSC thermogram measured after each blend was exposed to high temperature 18$0^{\circ}C$ and the fast curing conditions of a few tens seconds provide useful information on understanding the thermal processing of a blend at high speed. The measurements of resin flow time represent that there are three distinct stages of cure in the UPE/VE blends: induction, transition and macro-gelation stages, as similarly reported for UPE by others earlier. The thermal stability and flexural properties of the cured UPE are significantly improved by blending it with the VE, depending on the composition.