Changes in the Properties of Bio-Based Thermoplastic Polyurethanes with Different Chain Extenders

리시앙수,손미현,조을룡 한국고분자학회 2019 폴리머 Vol.43 No.4

Bio-based polyester polyol was synthesized by esterification using adipic acid and isosorbide. After the esterification, the bio-based polyurethanes (PUs) were synthesized by the reaction between the polyester polyol, isocyanate (4,4'-diphenylmethane diisocyanate) (MDI) and three chain extenders (1,3-propanediol (1,3-PD), 1,4-butanediol, or isosorbide) with a mixing ratio of 1:2.1:1. A thermoplastic polyurethane (TPU) without extender was used as a control. The structure analysis of bio-based TPUs were performed using FTIR, TGA, and DSC. Viscoelastic properties was investigated using a strain sweep test mode with a rubber process analyzer (RPA). The mechanical properties of samples (tensile strength and hardness value) were characterized with UTM and shore A hardness tester at room temperature. Waterand heat-resistance properties of the bio-TPUs were investigated using an oven and RPA with temperature sweep mode. The bio-based TPU which contained isosorbide as the chain extender showed the best mechanical and viscoelastic properties, and this polymer also showed great water and heat resistance during the test. The bio-based TPUs that contained liner chain extender 1,3-PD also showed excellent viscoelastic properties and heat resistance.

바이오 폴리에스터 폴리올에 의한 폴리우레탄의 합성 및 물성에 대한 연구

리시앙수,진경호,조을룡 한국고분자학회 2019 폴리머 Vol.43 No.4

2가 산인 azelaic acid, adipic acid와 2가 알코올인 isosorbide, 1,3-propanediol(1,3-PD)를 사용하여 4 가지 바이오 폴리에스터 폴리올을 합성하였다. 합성된 바이오 폴리에스터 폴리올을 4,4'-methylene bis(phenyl isocyanate)(MDI) 과 1:1.5의 비율로 혼합하여 바이오 폴리우레탄을 합성하였다. 바이오 폴리우레탄의 구조를 분석하기 위해서 FTIR, TGA, NMR 및 GPC를 사용하였다. 고분자 가공분석기(RPA)의 변형 스윕(strain sweep) 기능을 사용하여 바이오 폴리우레탄의 점탄성을 조사하였다. UTM, Shore A 기기를 사용하여 바이오 폴리우레탄의 인장강도, 경도를 측정하였다. Adipic acid와 1,3-PD에 의한 바이오 폴리에스터 폴리올과 MDI에 의한 바이오 폴리우레탄이 가장 좋은 기계적물성과 점탄성을 보여주었다. Isosorbide에 의한 2가지 바이오 폴리우레탄이 1,3-PD에 의한 바이오 폴리우레탄보다 더 작은 분자량 분포를 보였다. 본 연구는 미래의 친환경 폴리우레탄 재료의 개발 및 연구에 새로운 방향을 제공한다.

전선피복용 컴파운드의 제조에서 가소제의 종류와 첨가량에 따른 물성 변화 연구

리시앙수,이상봉,조을룡 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.2

The four different polymer compounds were manufactured with the two kinds of plasticizers [(di-2-ethylhexyl sebacate(DOS), and di-2-butyl sebacate(DBS)] and two different additive amounts(18, 26 phr) of the same plasticizer for making cable sheath for ship. Ethylene-vinylacetate, ethylene-propylene-diene-copolymer as matrix polymers and ethylene-vinylacetate grafted maleic anhydride as coupling agent were selected for compounding with fire retardant, closslinking agent, filler, and other additives besides plasticizer. The compound including DOS showed the higher Δ T than that including DBS at the same additive amount in the rheology test. And with increasing plasticizer, the compounds resulted in lower tensile strength and higher elongation by lubricating effect of plasticizer. DOS yielded better aging resistance and cold resistance than DBS due to the good heat resistance and low solidifying point of DOS compared to DBS.

전선피복용 컴파운드의 제조에서 난연제의 첨가량에 따른 물성 변화 연구

리시앙수,이상봉,조을룡 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.3

The three different polymer compounds were manufactured with the three different fire retardant (silane coated magnesium dihydroxide) contents, 180, 200, 220 phr, for making cable sheath for ship industry. In the research, ethylene-vinylacetate, polyethylene as matrix polymers and ethylene-vinylacetate grafted maleic anhydride as coupling agent were selected for compounding with fire retardant, closslinking agent, plasticizer, and other additives. In the evaluation. ΔT, Mooney viscosity, and tensile strength increased with the content of fire retardant. But it was found that too much fire retardant damaged aging resistance and cold resistance of the polymer compound.

전선피복용 고분자 컴파운드의 제조 및 물성 연구

리시앙수,이상봉,조을룡 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.1

The four different polymer compounds were manufactured to make cable sheath for ship industry. Two kinds of ethylene-vinyl acetate (EVA) were selected as main matrix polymers for compounding with fire retardant, crosslinking agent, filler, plasticizer, and other additives. The properties of the four compounded materials were investigated with the contents of fire retardant, silane coated aluminum hydroxide (S-ATH). Rheology, Mooney viscosity, and tensile strength increased with S-ATH contents by reinforcing effect. With increasing fire retardant amount, fire resistance increased, but cold resistance didn't show an obvious enhancement due to polar effect of vinyl acetate in EVA.

Study on Mechanical Properties Modification of Styrene butadiene rubber composites filling with Graphene and Molybdenum Disulfide

리시앙수,손미현,김유수,정예린,조을룡 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.3

Styrene-butadiene rubber (SBR) composites, incorporated with graphene, molybdenum disulfide and their hybrid in different filling ratio, were fabricated by a two roll-mill. The dispersion states of all the samples’ matrix were employed by carbon black dispersion tester. The curing properties of the pre-vulcanized rubber composites were investigated, after molding by heating press machine, the tensile strength, storage modulus, friction coefficient, the swelling property had also been tested according to ASTM. The composite G1M10 (filling with 1 phr graphene and 10 phr molybdenum) showed the best mechanical properties and viscoelastic properties in this research with a better filler dispersion state and more compact matrix structure.

Mechanical Performance and Oil Resistance Behavior of Modified Starch/Cellulose with Silica by Adsorption Method Filled into SBR Rubber Latex

Xiangxu Li(리시앙수),Ur-Ryong Cho(조을룡) 한국고분자학회 2018 폴리머 Vol.42 No.3

스티렌-부타디엔 고무 Latex 1502에 세가지 충전제(실리카, 실리카와 전분 혼성체, 실리카와 셀룰로오스 혼성체)를 콜로이드 흡착법으로 혼합하여 고무복합체를 제조하였다. 주사전자현미경을 통해서 가교 구성을 확인하였으며, 고무복합체의 비중, 경도, 인장강도, 저장탄성률, 동학역적 성능 및 내유성을 조사하였다. 실험의 결과에서 실리카와 전분/셀룰로오스 혼성체가 고무와 상호 침투 네트워크(Interpenetrating network)를 형성하여 좋은 보강 성능을 보였다. 그 중에서도 실리카와 셀룰로오스 10 phr 혼성체가 SBR 복합체에 가장 좋은 보강 효과를 보였다. Styrene-butadiene Rubber (SBR) composites were manufactured by colloidal adsorption method with three kinds of reinforcing agents (silica, starch-silica gel hybrid and cellulose-silica gel hybrid) and SBR l502 latex. The crosslink structure of compounds was observed with field-emission scanning electron microscope (FE-SEM). The density, hardness value, tensile strength, storage modulus, dynamic mechanical property, and oil resistance had been characterized. From the results of all tests, starch/cellulose-silica hybrid could make good reinforcement effect due to the interpenetrating network between hybrid and rubber matrix had been formed. The best filler was cellulose-silica hybrid 10 phr, which showed the best reinforcement effect with SBR compound.

Study on Styrene-Butadiene Rubber Composites Reinforced by Hybrids of Chitosan and Bamboo Charcoal/Silica

Xiang Xu Li(리시앙수),Ur Ryong Cho(조을룡) 한국고분자학회 2018 폴리머 Vol.42 No.5

키토산-폴리(비닐 알코올)(CS-PVA) 젤 및 충전제[뱀부차콜(BC) 및 실리카(SI)] 첨가에 대한 스티렌-부타디엔 고무의 점탄성 물성을 조사하였다. 스디렌-부타디엔 고무 라텍스에 상호 침투 가교 방법으로 제조된 키토산-PVA-뱀부차콜/실리카(BC/SI-CS-PVA) 혼성체를 혼합하여 고무복합체를 제조하였다. 고무 가공분석기의 변형 스윕(strain sweep) 및 주파수 스윕(frequency sweep) 기능을 사용하여 제조된 복합체(composites) 및 가황체(vulcanizates)의 점탄성을 조사하였다. 주사전자현미경 및 내마모성 측정을 통해서 가교 구성 및 기계적 물성을 확인하였다. 충전제의 종류에 따라서 스티렌-부타디엔 고무의 저장 탄성률(G") 및 탄성 토크(S")는 현저하게 증가하였다. 실험 결과를 통해서 BC-CS-PVA 혼성체가 가장 높은 저장 탄성률(G"), 탄성 토크(S") 및 내마모성의 결과를 보였다. 따라서 BC-CSPVA 혼성체가 SBR 복합체에 가장 좋은 점탄성 물성 및 기계적 물성의 보강 효과를 보였다. The influences of chitosan-poly(vinyl alcohol) (CS-PVA) gel and different fillers [bamboo charcoal (BC) and silica (SI)] on the viscoelastic properties of styrene-butadiene rubber (SBR) were studied in this work. The chitosan-PVAbamboo charcoal/silica (BC/SI-CS-PVA) hybrid fillers compatibilized SBR composites were fabricated by interpenetrating polymer network (IPN) method. The viscoelastic behaviors of the rubber composites and their vulcanizates were explored using a rubber processing analyzer (RPA) in the modes of strain and frequency sweeps. Storage modulus (G") and elastic torque (S") of the SBR increased significantly with the incorporation of different hybrid filler. BC-CS-PVASBR composite showed the highest storage modulus and elastic torque and abrasion resistance, which means BC-CSPVA hybrid filler could make the best reinforcement of viscoelastic and mechanical properties for SBR material in this research.

Study on Properties of Epoxidized Natural Rubber/Solution Styrene Butadiene Rubber Blend with Silica and Carbon Black in Different Filling Ratio

Xiang Xu Li(리시앙수),Su Young Jeong(정수영),Eun Ji Choi(최은지),Ur Ryong Cho(조을룡) 한국고분자학회 2019 폴리머 Vol.43 No.2

에폭시화 천연고무(ENR)와 솔루션-스디렌-부다디엔 고무(SSBR)를 150:50로 혼합한 고무 블렌드를 실리카 및 카본블랙을 충전제로 보강하였다. 제조된 고무 복합체의 물성은 고무 가공 분석기로 측정되었고, 형태학적 구조는 SEM으로 확인되었다. 열무게 분석, 인장강도, 경도, 마찰계수 및 발반탄성은 ENR/SSBR 블렌드의 물성을 확인하기 위하여 조사되었다. 모든 실험 결과에서, 복합체의 내열성, 경도, 인장강도 및 충전제의 분산성은 실리카 함량이 증가함에 따라 향상되었음을 알 수 있었다. 그 원인은 실리카와 ENR부분 사이에 수소 결합이라는 더 나은 결합의 형성이었다. 또한 블렌드의 마찰계수과 발반탄성은 카본블랙 함량이 증가함에 따라 향상되었다. 그 원인은 카본블랙과 블렌드의 결합효과(coupling effect) 및 윤활성이 개선됨에 기인함을 알았다. Epoxidized natural rubber (ENR) and solution styrene butadiene rubber were blended with a ratio of 150:50, which filled with silica and carbon black as reinforcement fillers. The curing properties of the rubber composites were tested by rubber processing analyzer and the morphological structure was characterized by SEM. The thermal decomposition behavior, tensile strength, hardness value, friction coefficient and resilience property were investigated to verify the property improvement of the SSBR/ENR composites. From the results of all the tests, it can be found that the heat resistance, hardness value, tensile strength and filler dispersion state of composites increased with increasing content of silica. The possible reason may be due to the fact that the silica could provide the better combination with ENR part due to the formation of hydrogen bond formation from O-Si-O. And with the increasing content of carbon black, the friction coefficient and resilience property were improved due to the lubrication and coupling effect of carbon black and blends.

Reinforcement Effects of Sulfonated Bamboo Charcoal-Chitosan (sBC-CS) Hybrid for Styrene-Butadiene Rubber Latex

Xiang Xu Li(리시앙수),Ji Hwan Oh(오지환),Shin Hye Kang(강신혜),Sun Ho Jang(장선호),Dam Hee Lee(이담희),Ur Ryong Cho(조을룡) 한국고분자학회 2017 폴리머 Vol.41 No.5

스티렌-부타디엔 고무에 4가지 충전제(키토산, 뱀부차콜 분말, 술폰화된 뱀부차콜, 술폰화된 뱀부차콜-키토산 혼성체)를 사용하여 라텍스 컴파운드법으로 고무복합체를 제조하였다. 주사전자현미경과 카본블랙 분산 테스트를 통해서 균일하게 충전제가 고무 매트릭스 내에 분산되었음을 확인하였으며, 가황된 고무복합체의 인장강도, 저장 탄성률, 내마모성, 마찰 계수, 팽윤 특성, 산소 투과도를 조사하였다. 술폰화된 뱀부차콜-키토산 혼성체가 다른 충전제보다 고무 매트릭스에 분산된 입자가 더 작고 잘 분산된 상태를 보였다. 또한 좋은 소수성 성질과 균일한 분산도로 충전제 중 가장 우수한 보강 성능을 보였다. Styrene-butadiene rubber (SBR) composites, incorporated with four kinds of fillers (chitosan, bamboo charcoal powder, sulfonated bamboo charcoal and sulfonated bamboo charcoal-chitosan hybrid) with similar filling ratio, were fabricated by a latex compounding method. Field emission scanning electron microscopy and carbon black dispersion tests were employed to confirm the uniform dispersion of filler in the matrix. The tensile strength, storage modulus, abrasion resistance, friction coefficient, swelling property, and oxygen transmission rates of the vulcanized rubber composites were investigated. The sulfonated bamboo charcoal-chitosan hybrid (sBC-CS) showed a smaller particle size and a better dispersion state compared with those of other fillers. In addition, this compound exhibited the best mechanical reinforcing performance among the four fillers with its great hydrophobic property and good dispersion rate.