Article
  • Effect of EVA-g-MAH on Water Absorption Properties of TPU/EVA Blends
  • Nam Kyun Kim*, **, Geon Wook Park*, Jae-Keun Yu*, Hyo Jun Kim*, and Kyu Hyun**,†

  • *Korea Institute of Footwear & Leather Technology, Busan 47154, Korea
    **School of Chemical Engineering, Pusan National University, Busan 46241, Korea

  • EVA-g-MAH 첨가에 따른 TPU/EVA 블렌드의 수분흡수 특성 연구
  • 김남균*, ** · 박건욱* · 유재근* · 김효준* · 현 규**,†

  • *한국신발피혁연구원, **부산대학교 응용화학공학부

  • Reproduction, stored in a retrieval system, or transmitted in any form of any part of this publication is permitted only by written permission from the Polymer Society of Korea.

Abstract

Thermoplastic polyurethane (TPU) as a thermoplastic elastomer (TPE) is attracting attention as a new alternative to rubber material due to its rubber elasticity and excellent processability by simplifying the kneading process without the vulcanization process. In addition, recycle-ability is also good. However, due to the strong polarity of the urethane group, it has the disadvantage of being vulnerable under a wet environment by high water absorption. In this study, ethylene vinyl acetate (EVA), which has a low water absorption rate and high affinity with other resins, was blended to solve this problem. Maleic anhydride-grafted EVA (EVA-g-MAH) was used as a compatibilizer to improve the compatibility of the TPU/EVA blend. With increasing concentration of the EVA-g-MAH, various parameters, for example, water absorption rate, thermal, and rheological properties, are investigated. Additionally, the morphology of TPU/EVA with EVA-g-MAH blend is also analyzed by SEM. When the content was 10 phr, the water absorption was minimized and mechanical properties was maximized due to improvement of interfacial adhesion. However, when EVA-g-MAH was added more than 10 phr, the water absorption rate tended to increase due to the polar MAH. Also, mechanical properties were reduced due to the lowered compatibility as the EVA-g-MAH acted like a plasticizer or an independent phase.


열가소성 엘라스토머(thermoplastic elastomer, TPE)인 폴리우레탄(thermoplastic polyurethane, TPU)은 고무의 탄성과 가황 공정이 불필요하여 혼련 공정의 간소화로 성형 가공이 용이한 열가소성 플라스틱 수지의 우수한 가공성을 동시에 발현하는 소재이자, 재활용이 가능하다는 장점으로 고무 소재의 대체 신소재로 주목받고 있다. 그러나 강한 극성을 띠는 우레탄기에 의해 수분흡수율이 높아 습윤한 환경에 취약하다는 단점을 지니고 있다. 본 연구에서는 이를 해결하고자 수분흡수율이 낮고 타 수지와 친화성이 높은 ethylene vinyl acetate(EVA)와 블렌드하였고, 이때 낮은 상용성을 개선하기 위해 말레산 무수물이 그라프트된 EVA-g-MAH(maleic anhydride)를 상용화제로 사용하여 TPU/EVA 블렌드의 특성을 평가하였다. 그 결과, 기계적, 열적, 유변학적, 모폴로지 특성 분석을 통해 EVA-g-MAH 함량에 따른 상용성의 척도를 판단할 수 있었으며, 함량이 10 phr 일 때 계면 접착력의 향상이 가장 우수하여 최적의 수분 흡수율과 기계적 물성의 결과를 확인할 수 있었다. 그러나 EVA-g-MAH가 10 phr 이상 첨가시 극성인 MAH로 인해 수분흡수율이 증가하는 경향을 보였다. 또한 가소제 역할을 하거나, 독립적인 상으로 거동하여 상용성을 저하했고 그 결과, 기계적 물성이 감소하는 한계를 보였다.


Keywords: thermoplastic polyurethane, ethylene vinyl acetate, thermoplastic polyurethane/ethylene vinyl acetate blend, maleic anhydride-grafted ethylene vinyl acetate.

  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2020 Impact Factor : 0.493
  • Indexed in SCIE

This Article

  • 2022; 46(2): 251-256

    Published online Mar 25, 2022

  • 10.7317/pk.2022.46.2.251
  • Received on Nov 24, 2021
  • Revised on Jan 6, 2022
  • Accepted on Jan 7, 2022

Correspondence to

  • Kyu Hyun
  • School of Chemical Engineering, Pusan National University, Busan 46241, Korea

  • E-mail: kyuhyun@pusan.ac.kr