• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.7 no.1
• /
• pp.18-26
• /
• 1998

The improvement of esthetic dentistry has been accelerated from the development of composite resin and dentin-enamel adhesive since 1980's. The indirect composite resin restorations have more accurate proximal contact point and occlusal form than direct restoration. And the side effect of resin shrinkage is minimal because the amount of composite used in oral cavity is limited in cement space. As a results, marginal leakage, hypersensitivity, secondary caries, and discoloration are significantly diminished. The first generation laboratory composite resin used in indirect resin restoration had been widespread in 1980's and the second generation laboratory composite resins were developed in 1990's. The second generation laboratory composite resins are called Ceramic Polymer. The physical properties of Ceramic Polymer are improved because of high content of inorganic filler, and the esthetics and biocompatibility are better than that of the first generation resin. So the application range using composite resin have been broadened. The purpose of this paper is to introduce Targis & Vectris system that is classified to second generation laboratory composite and to report several cases in which the system was utilized for restoration.

• Polymer Science and Technology
• /
• v.3 no.5
• /
• pp.369-378
• /
• 1992

• Polymer Science and Technology
• /
• v.3 no.5
• /
• pp.379-391
• /
• 1992

• The Journal of the Korean dental association
• /
• v.37 no.10 s.365
• /
• pp.785-795
• /
• 1999

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.11a
• /
• pp.320-323
• /
• 1995

In this paper, in order to improve withstand voltage properties of epoxy resin, IPN(interpenetrating polymer network) method was introduced and the influence was investigated. The sing1e network structure specimen(E series), simultaneous interpenetrating polymer network specimen(EMF series) and pseudo interpenetrating polymer network(EMP series) specimen were manufactured. In order to understand the internal structure properties, scanning electron microscopy method was utilized, rind glass transition temperature was measured. Also, AC voltage dielectric strength, tensile strength and impact strength were measured to investigate influence upon electrical and mechanical properties. As a result, it was confirmed that simultaneous interpenetrating polymer network specimen was the most execellent.

• Korean Journal of Agricultural Science
• /
• v.37 no.1
• /
• pp.87-96
• /
• 2010

This study was performed to evaluate the planting properties of herbaceous plant and cool-season grass in porous polymer blocks that were manufactured by using recycled coarse aggregates and unsaturated polyester resin to develop environmentally friendly planting blocks. Unsaturated polyester resin, natural and recycled coarse aggregates and $CaCO_3$ were used. The mix proportions were determined to satisfy the requirement for the workability and slump according to aggregate sizes(5-10 and 5-20mm). Tests for the void ratio and compressive strength of porous polymer concrete were performed at curing age 7 days. Also, porous polymer block using recycled coarse aggregates were applied to kinds of plants such as tall fescue, Perennial ryegrass, Lesedeza and Alfalfa. After seed, initial germination, germination ratio, cover view and growth length for planting blocks were estimated by various methods.

• KCI Concrete Journal
• /
• v.13 no.2
• /
• pp.58-66
• /
• 2001

Recently, polymer-modified mortar has been studied for proposed use on industrial floors as top coat with thin thickness, typically 5~15mm. The purpose of this study is to evaluate basic properties of self-leveling materials using polymer dispersions as kinds of SBR, PAE, St/BA with thin coat (under 3mm). Superplasticizer and thickener have been included in the mixes to reduce bleeding and drying shrinkage as well as to facilitate the workability required. The self-leveling materials using four types of polymer dispersion are prepared with polymer-cement ratio which respectively range from 50% and 75%, and tested for basic characteristics such as unit weight, air content, flow, consistency change and adhesion in tension. From the test results, the self-leveling materials using PAE emulsion at curing age of 28days are almost equal to those of conventional floor using urethane and epoxy resin. The adhesion in tension of self-leveling mortars using SBR latex and PAE emulsion at curing age of 3days is over 17 kgf/cm$^2$(1.67MPa). Consistency change is strongly dependent on the type of polymer dispersion. It is concluded that the self-leveling materials using polymer dispersions can be used in the same manner as conventional floor using thermosetting resin in practical applications, in the selection of polymer dispersions.

• Polymer(Korea)
• /
• v.31 no.2
• /
• pp.105-110
• /
• 2007

We investigated resin, thinner, painting, and injection for analyzing the chemical effect of polymer, and made the optimum solution with the best performance of ABS (acrylonitrile butadiene styrene) resin. The effect depended on chemical material especially its chemical and physical properties instead of mechanical transformation. When we looked over ABS resin, injection, chemical material and painting, we found out thinner was the main factor for painting problem. Throughout this test, we could solve the problem, secure the system for control process and drop many factors for changing quality.

• Journal of the Korean Ceramic Society
• /
• v.37 no.3
• /
• pp.280-287
• /
• 2000

Adsorption behavior and amount of phenolic resin followed silica (SiO2) formation onto silicon nitride(Si3N4) surface were investigated using electrokinetic sonic amplitude (ESA) technique and with UV spectrometer, to fabricate Si3N4/SiC nano-composite based on reaction between SiO2 formed and phenolic resin absorbed onto Si3N4 particle. The amount of SiO2 formed and carbon from phenolic resin absorbed onto Si3N4 surface were calculated quantitatively to adjust the reaction between SiO2 and phenolic resin, resulting in no residual SiO2 and carbon. As a result, pre-heated tempeature for optimized reaction was below 25$0^{\circ}C$, in which there was no residual SiO2 and carbon.

• Journal of the Korea Concrete Institute
• /
• v.17 no.3 s.87
• /
• pp.335-342
• /
• 2005

In this paper, fundamental properties of Polymer Concrete(PC), made from unsaturated polyester resin based on recycled PET and recycled aggregate were investigated. Mechanical properties include strength, modulus of elasticity, and chemical resistance. Resins based on recycled PET and recycled aggregate offer the possibility of low source cost for forming useful products, and would also help alleviate an environmental problem and save energy. The results of test for resin contents and recycled aggregate ratio we, first, the strength of Polymer Concrete made with resin based on recycled PET and recycled aggregate increases with resin contents relatively, however beyond a certain resin contents the strength does not change appreciably, Second, the relationship between the compressive strength and recycled aggregate ratio at resin $9\%$ has a close correlation linearly whereas there is no correlation between the compressive strength and the flexural strength of RPC with recycled aggregate ratio. Third, the effect of acid resistance at resin $9\%$ was found to be nearly unaffected by HCI, whereas the PC with $100\%$ recycled aggregate showed poor acid resistance. Unlike acid, alkali nearly does not seem to attack the RPC as is evident from the weight change and compressive strength. And last, In case of stress-strain curve of polymer concrete with $100\%$ of natural aggregate and $100\%$ recycled aggregate it is observed the exceptional behavior resulting in different failure mechanisms of the material under compression.