• Elastomers and Composites
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• 제50권2호
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• pp.98-102
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• 2015

A series of polyurethane-acrylate hybrids were synthesized by 2-step emulsion polymerization of a variety of acrylate monomers such as 2-hydroxy ethyl methacrylate (HEMA), methyl methacrylate (MMA). Experiment was performed to improve stability and emulsibility of surface treatment agent, and it was found that the polyurethane-acrylate hybrids having an optimum composition (MMA : 20%, LA(EO)3-S : 3% and TDA-7 : 5%) was shown to be quite surface active in the solid contents. These results suggests that the optimal polyurethane-acrylate hybrids in this study have high potential as top coating agent, which may have high gloss and excellent properties.

• Elastomers and Composites
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• 제27권4호
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• pp.267-274
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• 1992

Polydimethylsiloxane(PDMS)-containing polyurethane coating materials were synthesized because PDMS-based elastomers have unique properties including an extremely low glass transition temperature, good thermal and oxidative stability, and good dielectric properties. In this experiment a vinyl copolymer which consisted of vinyl chloride, vinyl acetate, vinyl alcohol, and maleic acid was used, and Coronate L was used as a polyisocyanate. PDMS-containing polyurethane was synthesized from polydimethylsiloxane, MDI, and 1,4-butanediol. Films were casted by reaction of viny copolymer, Coronate L, and PDMS-containing polyurethane. Thickness of tile films were $150-170{\mu}m$ and the films were characterized by IR, DSC, and Instron.

• Elastomers and Composites
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• 제33권1호
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• pp.3-9
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• 1998

The production of polyurethane polymer has been increased because of their unique properties and variety process methods available. The generation of their wastes also increases with products. These byproducts of industrialization seriously threaten the environmental demanding. Therefore, development of the recycling technologies have been required. The main propose of this study is to develop the recycling technology of waste polyurethane from a footwear scrap. This technique is composed of the following procedure : crushing, devulcanizing, pelletizing, washing and drying. The pellet was characterized with various methods. The recycled polyurethane(RPU) was blended with HIPS(high impact polystyrene) and investigated morphologically and rheologically. The experimental results showed that the addition of 20% HIPS to RPU was limited without mechanical performance of the superial properties of a virgin polyurethane. We believe that these technical information make possible to develop a rational engineering product.

• Elastomers and Composites
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• 제35권3호
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• pp.227-235
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• 2000

신발스크랩으로부터 발생되는 폐우레탄 발포체(waste urethane foam)와 폐우레탄(waste urethane scrap, $5{\sim}7mm$)의 재활용을 위하여 첫째, 양액재배용 배지의 구성 요소로 사용하여 장미 재배 적용가능성을 조사하였으며, 둘째, 폐우레탄으로부터 재생우레탄(Recycled Thermoplastic Polyurethane : RTPU)을 제조하여 RTPU와 HIPS(High Impact Polystyrene)를 블렌드한 후 이의 적용성을 확장하기 위하여 RTPU/HIPS 블렌드물에 amine계 발포제를 사용하여 발포체를 제조하였다. 양액재배용 배지의 구성요소로서 폐고무의 재활용에 있어서는 식물의 성장에 영향을 미치는 pH, 전기전도도, 생육 등을 조사하였으며, 폐우레탄 발포체의 물성은 TGA, DSC, FT-IR, SEM등을 이용하여 조사하였다. 본 연구는 폐우레탄 재활용 가능성의 다각화에 목적을 두었다.

• Elastomers and Composites
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• 제50권1호
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• pp.35-48
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• 2015

Polyhedral oligomeric silsesquioxane (POSS) is an important inorganic-organic hybrid material with a three-dimensional structure. Polyurethane (PU) is a widely applied polymer that has versatile properties with the change of two phase structure. When POSS is incorporated into PU by physical or chemical methods, many properties can be greatly improved, such as mechanical properties, thermal stability, biodegradation resistance, and water resistance. This paper reviews the recent progress in preparation, structure, and performance of POSS-modified polyurethane from the viewpoint of physical blending and chemical modification.

• Elastomers and Composites
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• 제52권1호
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• pp.81-85
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• 2017

In order to improve the water resistance, we synthesized waterborne polyurethane by using polyester polyol, poly(propylene carbonate) (PPC), 4,4'-dicyclohexylmethane diisocyanate ($H_{12}MDI$), and dimethylolpropionic acid (DMPA). The properties of the synthesized waterborne polyurethane using poly(propylene carbonate) (WPUP) were evaluated by FT-IR, $^1H-NMR$, GPC, DSC, TGA, and UTM. The mechanical properties increased while the adhesion properties decreased with the increase in the amount of PPC. The highest water resistance was shown when the ratio of polyester polyol to PPC was 9:1.

• Elastomers and Composites
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• 제34권4호
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• pp.285-291
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• 1999

Effects of catalysts on network structure, hard segment length and distribution of polyurethane foams in the absence of catalysts were investigated. CFC free all MDI-based poly urethane foams were prepared from poly(ethylene adipate)glycol, 4,4'-diphenylmethane diisocyanate, and water. Amino catalysts used were 1,4-diazabicyclo[2,2,2]octane(DABCO), N, N,N',N'-tetramethyl--hexane-1,6-diamine(MR), bis(2-methylamino ethyl)ether(ET), 1,8-diazabicyclo-[5,4,0]-undecene-7(DBU). Dibutyltindilaurate(DBTL) as control was also used. Hard segment components of polyurethane foams were obtained by a selective degradation of polyester chains with 0.01N KOH-methanol solution. The PUFs with DBU catalyst contained more amount of isocyanurate components than other PUFs. On the other hand, the PUFs with ET, MR, DBTL catalysts contained more amount of allophanate and biuret component than the other PUFs.

• 분석과학
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• 제8권4호
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• pp.623-630
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• 1995

Silicone rubber-based sodium-selective membranes are developed for solid-state ion sensors. It was shown that the potetiometric performance of SR-based membranes are greatly dependent on the type of neutral carriers employed; among the three ionophores, N,N,N',N'-tetracyclohexyl-1,2-phenylenedioxydiacetamide (ETH 2120), bis[(12-crown-4)methyl]dodecylmethylmalonate (D12C4DMM) and monensin methyl ester (MME), examined, only ETH 2120 was compatible with the SR-based matrix. Addition of about 20 wt% plasticizer to the SR-based matrix provided the resulting membranes with potentiometric properties essentially equivalent to those of the corresponding PVC-based membranes. Owing to the strong adhesive strength of SR-based membranes, the CWEs coated \vith those membranes exhibited long lifetime with conventional electrode-like performance. Blending of PU into the SR matrix increased the lifetime of CWEs from two weeks to one month.

• Elastomers and Composites
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• 제47권4호
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• pp.318-328
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• 2012

본 연구에서는 blocked isocyanate와 하이브리드 기술을 이용해서 1액 경화형 폴리우레탄 탄성체를 제조하였다. 1액 경화형 하이브리드 폴리우레탄의 제조를 위해서 hydroxyl group을 포함하는 실리카 하이브리드를 합성하고 입자크기, 형태 및 탄성체 내의 하이브리드 입자분포를 확인하였다. 또한, 열해리특성, 기계적 물성, 성형특성을 조사하였다. 1액 경화형 폴리우레탄 탄성체의 열해리 특성을 평가한 결과 온도가 높을수록, 열처리 시간이 길어질수록 blocking된 isocyanate의 해리가 더 잘 진행되었다. 합성된 실리카 하이브리드는 직경이 23~27 nm이고 구형이었으며 하이브리드 폴리우레탄의 단면을 FE-SEM과 EDS를 사용해서 분석한 결과 하이브리드 입자가 폴리우레탄 분자구조 내에 잘 분산되어있는 것을 확인하였다. 하이브리드 폴리우레탄의 경우에는 하이브리드를 포함하지 않는 폴리우레탄 탄성체에 비해 기계적물성, 내마모성 및 열적특성이 향상되었으며 가소제를 사용하는 경우에는 물성의 변화가 거의 없는 것으로 확인되었다.

• Elastomers and Composites
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• 제39권3호
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• pp.209-216
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• 2004

Polyurethane prepolymer에 2-hydroxyethylmethacrylate(HEMA)와 acrylamide(AA)를 반응 시켜 두 가지 타입의 polyurethane-acrylate 중합체들을 합성하였다. 합성된 중합체들을 소량의 benzyl chloride와 증류수를 이용하여 수용성 중합체인 폴리우레탄-아크릴레이트계 양이온성 보류향상제를 제조하였다. 이렇게 두 가지 형태로 제조된 중합체에 대하여 보류향상제로서 중요한 특성인 보류, 탈수특성 및 비압축강도 등의 물성들을 다양한 방법으로 고찰하였다. 합성된 폴리우레탄-아크릴레이트계 양이온성 보류향상제는 rpm에 따라 큰 변화 없이 70% 내외의 보류도를 유지하였으며, 합성한 보류향상제의 첨가로 인한 화학적 산소 요구량(COD)의 경우는 미첨가시의 COD보다 상당히 낮은 값이 관찰되었다. 탈수량의 경우 무처리한 펄프보다 보류향상제의 처가 시에 탈수성이 향상되었으며, 보류향상제의 첨가 시 비압축강도가 소량 증가되었고, PU-HEMA가 PU-AA보다 우수한 강도를 나타내었다.