• 제목/요약/키워드: polymer modification

검색결과 475건 처리시간 0.022초

Poly(N-vinylpyrrolidone)이 그래프트된 Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) 공중합체의 합성 및 결정화 거동 (Preparation and Crystallization Behavior of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Grafted with Poly(N-vinylpyrrolidone))

  • Wang, Wei;Zhang, Yu;Chen, Yanmo
    • 폴리머
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    • 제31권5호
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    • pp.385-392
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    • 2007
  • Poly (N-vinylpyrrolidone) (PVP) groups were grafted onto a poly(3-hydroxybutyrate-co-3-hydroryvalerate) (PHBV) backbone in order to modify its properties and synthesize a novel biocompatible copolymer. The crystallization behavior of PHBV and grafted PHBV was investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). During the cooling-induced crystallization process, the crystallization temperature and the crystallization rate of the grafted PHBV decreased with increasing PVP weight fraction. On the heating scans of all grafted PHBV samples, a new crystallization exothermic peak appeared at almost the same temperature, suggesting the operation of a recrystallization process, while the melting temperature ($T_m$) and the apparent enthalpy of fusion (${\Delta}H_f$) were not affected by graft modification. During the isothermal crystallization process at the same temperature, the presence of side PVP groups decreased the spherulitic growth rate and the spherulitic band spacing with increasing PVP weight fraction in samples.

Recent Advances in Carbon-Nanotube-Based Epoxy Composites

  • Jin, Fan-Long;Park, Soo-Jin
    • Carbon letters
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    • 제14권1호
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    • pp.1-13
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    • 2013
  • Carbon nanotubes (CNTs) are increasingly attracting scientific and industrial interest because of their outstanding characteristics, such as a high Young's modulus and tensile strength, low density, and excellent electrical and thermal properties. The incorporation of CNTs into polymer matrices greatly improves the electrical, thermal, and mechanical properties of the materials. Surface modification of CNTs can improve their processibility and dispersion within the composites. This paper aims to review the surface modification of CNTs, processing technologies, and mechanical and electrical properties of CNT-based epoxy composites.

고분자 일렉트렛트의 전위분포 시뮬레이션 (Simulation of Electrostaticc Contour un Polymer Electret)

  • 이수길;김성렬;이한성;이준웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 추계학술대회 논문집
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    • pp.317-319
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    • 1995
  • In this Study, The Electrostatic Coutour Distribution in Polymer Electret Acoustic Sensor is calcuated using Finite Element Method. As a result the Electrostatic Countour Distribution is visualized and the design modification could be processed.

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Preparation and Properties of Polyolefin Graft Polymer available as a Primer for Polyurethane Adhesive (I) Synthesis of polyolefins with cyclic acid anhydride by free radical graft polymerization

  • Ryu, Ki Jung;Kim, Min Jung;Min, Seong Kee;Lee, Won Kee;Park, Chan Young
    • Elastomers and Composites
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    • 제50권2호
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    • pp.119-125
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    • 2015
  • Because of their low surface free energy and absence of polar groups at the surface, polyolefins are substrates whose wetting and adhesion are very difficult. Free radical grafting of monomers to backbone polymer is one of the most attractive ways for the chemical modification of polymers. Synthesis of graft copolymer through graft polymerizations of PE and/or PP with phthalic anhydride (PhAn) was made and FTIR spectra of the graft polymer were the examined. And also the effects of phthalic anhydride content on the grafting ratio, thermal properties and contact angle of the graft polymer were examined.

다중벽 탄소나노튜브/폴리(에틸렌 옥사이드) 복합체 합성 (Synthesis of Multi-walled Carbon Nanotube/Poly(ethylene oxide) Hybrids)

  • 홍채환;한도석;남병욱
    • 폴리머
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    • 제34권3호
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    • pp.198-201
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    • 2010
  • 탄소나노튜브의 응집력을 완화하기 위한 표면 개질과 고분자 소재와의 상용성을 유도하기 위하여, 친수성 고분자를 도입하는 연구를 진행하였다. 산처리를 통한 표면 기능화를 시행하였으며, 카복실기 도입 탄소나노튜브를 thionyl chloride을 사용하여 acyl chloride로 치환한 후 저분자량의 아민 말단 poly(ethylene oxide)를 공유결합으로 도입하였다. TGA를 통하여 탄소나노튜브 표면에 도입된 고분자의 함량을 계산하였으며, 탄소나노튜브 표면에 도입된 고분자의 표면 형상을 SEM과 TEM을 통하여 직경이 증가하는 것을 확인할 수 있었다.

Effect of Allyl Modified/Silane Modified Multiwalled Carbon Nano Tubes on the Electrical Properties of Unsaturated Polyester Resin Composites

  • Swain, Sarojini;Sharma, Ram Avatar;Patil, Sandip;Bhattacharya, Subhendu;Gadiyaram, Srinivasa Pavan;Chaudhari, Lokesh
    • Transactions on Electrical and Electronic Materials
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    • 제13권6호
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    • pp.267-272
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    • 2012
  • Considering the properties of the carbon nano tubes (CNT), their inclusion into the polymer matrix vastly increases the properties of the resultant composite. However, this is not the case due to the poor interfacial adhesion of the CNT and the polymer matrix. The present approach focuses on increasing the interaction between the polymer matrix and the CNT through the chemical modification of the CNT resulting in allyl ester functionalized carbon nanotubes (ACNT) and silane functionalized carbon nano tubes (SCNT) which are capable of reacting with the polymer matrix during the curing reaction. The addition of ACNT/SCNT into unsaturated polyester resin (UPR) resulted in the improvement of the electrical properties of resulted nanocomposites in comparison to the CNT. The surface resistivity, volume resistivity, dielectric strength, dry arc resistivity, and the comparative tracking index of the nanocomposites were significantly improved in comparison to CNT. The chemical modification of CNT was confirmed via spectroscopy.

표면개질을 이용한 폴리에틸렌 필름과 알루미늄간의 열융착 (Thermal Lamination of Polyethylene Film on Aluminum by Surface Modification)

  • 조동련;윤타송
    • 폴리머
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    • 제25권4호
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    • pp.594-601
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    • 2001
  • 표면을 개질시켜 극성기를 도입한 다음 열융착시키는 방법으로 접착제를 사용하지 않고도 폴리에틸렌 필름과 알루미늄 판을 직접 접합시킬 수 있는지를 살펴보았다. 폴리에틸렌 필름은 산소 및 아크릴산 플라즈마로 처리하여 극성기를 도입하였으며, 알루미늄 판은 끓는 물로 처리하거나 diaminocyclohexane 플라즈마로 처리하여 극성기를 도입하였다. 폴리에틸렌 필름의 표면만을 개질시킬 경우에도 상당히 높은 접착력을 얻을 수 있었으며, 알루미늄 판의 표면까지 개질시킬 경우에는 접착시험시 폴리에틸렌 필름이 끊어질 정도로 높은 접착력을 얻을 수 있었다. 특히, 아크릴산플라즈마로 처리한 폴리에틸렌 필름과 diaminocyclohexane 플라즈마로 처리한 알루미늄 판을 접합시킬 경우에는 필름 표면의 카르복실기와 판 표면의 아민기가 반응하여 아마이드 그룹을 형성하는 화학적 결합에 대한 가능성도 보여주었다.

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