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Study on the Improving Thermal and Mechanical Properties of Eco-friendly Materials used for Training Ammunition

연습용 탄약 친환경 재료의 내열성 및 기계적 특성 향상에 관한 연구

  • 김명현 (국방기술품질원 탄약센터) ;
  • 손병철 (국방기술품질원 탄약센터) ;
  • 이영태 (국방기술품질원 탄약센터)
  • Received : 2018.02.22
  • Accepted : 2018.05.04
  • Published : 2018.05.31

Abstract

Unlike live ammunition which has killing power due to the use of high explosives, training ammunition has only the limited explosive effect needed for training purposes, so the risk of accidents is lowered. Because training ammunition is used in large quantities during military drills, the problem of environmental pollution occurs. As most of the waste is left out in the training field, using bio-degradable polymers such as Polylactic Acid (PLA) can provide a solution to these environmental issues. However, bio-degradable polymers such as PLA usually have poor thermal and mechanical properties compared with other general purpose polymers, so they need to be improved before they can be used for military purposes. In this study, Talc is added to the PLA used for the parts of Training Grenades to improve some of their properties and the changes of their thermal and mechanical properties were verified. In the case of the 1 wt.% ~ 5 wt.% PLA/Talc blends, the thermal properties were improved in proportion to the content of Talc, but the best mechanical properties were observed for the 1 wt.% and 3 wt.% PLA/Talc blends.

고성능 폭약에 의한 살상효과를 발휘하는 전투용 탄약과는 달리 연습용 탄약은 유사한 폭발 효과를 구현하여 훈련용으로 사용되는 탄약으로, 악작용에 의한 안전사고의 위험성이 개선된 훈련용 탄약이다. 연습용 탄약은 훈련 과정에서 대량으로 사용되기 때문에 폐 탄약에 의한 환경오염 문제가 발생하고 있다. 대부분의 폐 탄약은 훈련장 내에 방치되는 실정인데, 폴리유산(PLA)과 같은 생분해성 고분자를 사용할 경우 환경 문제를 해결할 수 있을 것이다. 하지만 PLA와 같은 대부분의 생분해성 고분자는 범용 고분자에 비해 내열성 및 기계적 특성이 취약하므로 군사적 목적으로 사용하기 위해서는 내열성 및 기계적 특성의 개질이 필요하다. 본 연구에서는 연습용 수류탄의 주요 부품 원재료로 사용되는 PLA에 활석(Talc)을 첨가하여 내열성 및 기계적 특성 변화를 확인하였다. Talc 비율 1 wt.% ~ 5 wt.%의 PLA/Talc 블렌드에서, 활석 비율에 따라 내열성이 향상되었고, 1 wt.% 및 3 wt.%에서 최적의 기계적 특성을 확인하였다.

Keywords

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