To improve the mechanical properties of hydroxyapatite (HA)/waterborne polyurethane (WBPU) composites, the hydroxyl group of HA was modified by urethane reactions: the hydroxyl groups of HA were reacted with aliphatic or cyclic diisocyanate, and then the modified HAs were extended by adding polyol and/or ε-caprolactone. Composites were prepared by the prepolymer process method: the modified HA was directly pured into the urethane reaction of isocyanate and polyol. The properties of modified HA/WBPU composites were investigated by thermogravimetric analysis, tensile strength, and water resistance. The results showed that the reactivity of aliphatic diisocyanate to the hydroxy group of HA was faster than that of cyclic one. Comparing to those of pure HA/WBPU composite films, the thermal stability, water resistance, and mechanical properties of the modified composite films increased with a degree of modification of HA.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 시약
  2.2. HA 개질
  2.3. HA/WBPU 복합체 제조
  2.4. HA/WBPU 복합체의 분석
 3. 결과 및 고찰
 4. 결 론
 참 고 문 헌

• 이준근(부경대학교 고분자공학과) | Jungun Lee (Department of Polymer Engineering, Pukyong National University)
• 이원기(부경대학교 고분자공학과) | Won-Ki Lee (Department of Polymer Engineering, Pukyong National University) Corresponding author
• 박상보(부경대학교 고분자공학과) | Sang-Bo Park (Department of Polymer Engineering, Pukyong National University)
• 박찬영(부경대학교 고분자공학과) | Chan-Young Park (Department of Polymer Engineering, Pukyong National University)
• 민성기(부경대학교 고분자공학과) | Sung-Kee Min (Department of Polymer Engineering, Pukyong National University)
• 장성호(부산대학교 지역환경시스템공학과) | Sung-Ho Jang (Department of Regional Environmental System Engineering, Pusan National University)