Elastomers and Composites

The Rubber Society of Korea (한국고무학회)
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Effects of Mold Temperatures on Physical Properites of Injection Molded Thermoplastic Polyurethanes

사출성형 열가소성 폴리우레탄의 물리적 성질에 미치는 금형 온도 영향

  • Lee, Dai-Soo (Division of Environmental and Chemical Engineering Chonbuk National University) ;
  • Kim, Seong-Geun (Division of Environmental and Chemical Engineering Chonbuk National University) ;
  • Nguyen, Vinh-Khanh (Division of Environmental and Chemical Engineering Chonbuk National University) ;
  • Lee, Wing-Ji (Division of Environmental and Chemical Engineering Chonbuk National University) ;
  • Pang, Su-Jin (Division of Environmental and Chemical Engineering Chonbuk National University)
  • 이대수 (전북대학교 환경화학공학부) ;
  • 김성근 (전북대학교 환경화학공학부) ;
  • 구엔빈칸 (전북대학교 환경화학공학부) ;
  • 이명걸 (전북대학교 환경화학공학부) ;
  • 방수진 (전북대학교 환경화학공학부)
  • Published : 2004.12.31
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Abstract

Ester- and ether-based thermoplastic polyurethanes of different hardness were injection molded at different mold temperatures and effects of mold temperature on the physical properties of TPUs were investigated. Glass transition temperatures of soft segments of TPUs were hardly changed by mold temperatures. The phase separation of soft and hard segments of injection molded TPUs were affected little by mold temperatures. However, crystallinity of hard segments, temperature range of rubbery plateau, and tensile strength of injection molded TPUs decreased with increasing mold temperatures for TPUs of high hardness. However, injection molded TPUs of low hardness showed increases of crystallinity of hard segments, temperature range of rubbery plateau, and tensile strength with increasing mold temperatures. Different physical properties of injection molded TPUs depending on mold temperatures were attributed to different crystallization and physical crosslinking effects of hard segments.

경도를 달리하는 에스테르계 및 에테르계 열가소성 폴리우레탄(thermoplastic polyurethane: TPU)의 사출에서 금형 온도가 물리적 성질에 미치는 영향을 조사하였다. TPU의 연질부 유리전이온도는 금형 온도 변화에 따라 거의 변화하지 않았으며, 연질부와 경질부의 상분리는 금형온도의 영향을 별로 받지 않는 것으로 판단되었다. 그러나 에스테르계와 에테르계 TPU는 종류에 관계없이 공통적으로 경도가 높은 TPU들은 금형온도를 높이는 경우 결정성, 고무상 평탄 온도영역, 인장강도가 감소하였으나, 경도가 낮은 TPU들은 오히려 결정성, 고무상 평탄 온도영역, 인장강도의 증가를 보였다. TPU의 사출 성형 금형 온도에 따른 물리적 성질의 차이를 결정성 경질부의 결정화와 물리적 가교효과 차이로 해석하였다.

Keywords

References

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