DOI QR코드

DOI QR Code

Wood Flour 폴리프로필렌 복합재료의 기계적 특성: 반복적 온도 변화의 영향

Mechanical Properties of Wood Flour Polypropylene Composites: Effect of Cycled Temperature Change

  • 이선영 (국립산림과학원 녹색자원이용부 환경소재공학과) ;
  • 전상진 (국립산림과학원 녹색자원이용부 환경소재공학과) ;
  • 도금현 (국립산림과학원 녹색자원이용부 환경소재공학과) ;
  • 박상범 (국립산림과학원 녹색자원이용부 환경소재공학과) ;
  • 최수임 (순천대학교 생명산업과학대학 산림자원학과)
  • Lee, S.Y. (Department of Forest Resources Utilization, Korea Forest Research Institute) ;
  • Chun, S.J. (Department of Forest Resources Utilization, Korea Forest Research Institute) ;
  • Doh, G.H. (Department of Forest Resources Utilization, Korea Forest Research Institute) ;
  • Park, S.B. (Department of Forest Resources Utilization, Korea Forest Research Institute) ;
  • Choi, S.I. (Department of Forest Resources, Sunchon National University)
  • 투고 : 2011.07.22
  • 심사 : 2011.08.09
  • 발행 : 2011.09.30

초록

본 연구에서는 반복적인 온도변화가 목분(50 wt.%와 70 wt.%)이 첨가된 폴리프로필렌 WPC(Wood Plastic Composites)의 기계적 특성에 미치는 영향을 조사하였다. WPC의 휨탄성계수(flexural modulus)와 휨강도 (flexural strength)는 반복 회수에 상관없이 동결 융해 시험에서 계면접착력의 약화 때문에 감소하는 경향을 보였다. 목분의 함량이 높을 때, 휨탄성계수의 감소가 비교적 높았다. WPC의 휨탄성계수와 휨강도는 고온($60^{\circ}C$) 저온 ($-20^{\circ}C$) 반복시험 후 고온에서 감소하고 저온에서 증가되었다. 폴리프로필렌(polypropylene, PP)의 유리전이점 (glass transition temperature: $-10^{\circ}C$) 보다 낮은 저온($-20^{\circ}C$에서 WPC는 높은 강성(stiffness)과 강도 (strength)를 유발시키는 유리상태(glassy state)로 존재한다. 고온에서 목분의 함량이 낮은 WPC가 연성의 증가 때문에 낮은 휨탄성계수와 휨강도를 보였다.

The effect of cycled temperature change on the mechanical properties of wood flour(50 wt.% and 70 wt.%) polypropylene WPC(Wood Plastic Composites) was investigated in this study. Flexural modulus and flexural strength of the WPC showed a decrease due to the degradation of interfacial adhesion between polymer matrix and wood flour by the freeze-thaw test regardless of the cycled number. At the higher loading level of wood flour, the reduction of the flexural modulus was remarkable. After the cycled heat-freeze test, it was found that the flexural modulus and flexural strength of the WPC were lower at the high temperature ($60^{\circ}C$) and higher at the low temperature ($-20^{\circ}C$). At the low temperature ($-20^{\circ}C$) which is below glass transition temperature of polypropylene ($-10^{\circ}C$), WPC is in a glassy state which brings about the high stiffness and strength. At the high temperature ($60^{\circ}C$), the flexural modulus and flexural strength of the WPC with 50 wt.% wood flour were lower because of the increase of polymer ductility.

키워드

참고문헌

  1. C. Clemons, "Wood-plastic composites in the United States, the interfacing of two industries", For. Prod. J., 52, 10 (2002).
  2. H.S. Yang, H.J. Kim, J.I. Son, H.J. Park, B.J. Lee, and T.S. Hwang, "Rice-husk flour filled polypropylene composites; mechanical and morphological study", Compos. Struct., 63, 305 (2004). https://doi.org/10.1016/S0263-8223(03)00179-X
  3. J.I. Son, H.S. Yang, and H.J. Kim, "Physico-mechanical properties of paper sludge-thermoplastic polymer composites", J. Thermoplast. Compos., 17, 509 (2004). https://doi.org/10.1177/0892705704038471
  4. S.Y. Lee, I.A. Kang, B.S. Park, G.H. Doh, and B.D. Park, "Effects of fillers and coupling agent on the properties of bamboo fiber-reinforced polypropylene composites", J. Reinf. Plast. Compos., 28, 2589 (2008).
  5. A.J. Schildmeyer, M.P. Wolcott, D.A. Bender, and P.E. Masce, "Investigation of the temperature-dependent mechanical behavior of a polypropylene-pine composite", J. Mater. Civil. Eng., 21, 460 (2009). https://doi.org/10.1061/(ASCE)0899-1561(2009)21:9(460)
  6. M. Tajvidi and N. Motie, "Mechanical performance of hemp fiber polypropylene composites at different operating temperature", J. Reinf. Plast. Compos., 29, 664 (2010). https://doi.org/10.1177/0731684408100266
  7. J.M. Pilarski amd L.M. Matuana, "Durability of wood flour-plastic composites exposed to accelerated freeze-thaw cycling. II. High density polyethylene matrix", J. Appl. Polym. Sci., 100, 35 (2006). https://doi.org/10.1002/app.22877
  8. M. Tajvidi and S. Haghdan, "Effects of accelerated freeze-thaw cycling on physical and mechanical properties of wood flour/PVA composites", J. Reinf. Plast. Compos., 28, 1841 (2009). https://doi.org/10.1177/0731684408090367
  9. ASTM D7031-04, "Standard guide for evaluating mechanical and physical properties of wood-plastic composite products", ASTM Annual Book, Vol. 08. 01. (2004).
  10. ASTM D790-07, "Standard guide for flexural properties of unreinforced and reinforced plastics and electrical insulating materials", ASTM Annual Book, Vol. 08. 01. (2007).