複合材料係指兩種或兩種以上物理及化學性質不同之材料,進行結合而得的一種新材料。常見的複合材料一般都是結合有機材料和無機材料而成的,利用無機材料的高強度、高硬度、熱穩定性等,結合有機材料的高韌性、可加工性等,製備出具有兩造特性之複合材料。 本研究為利用玄武岩短纖維來增強熱塑性聚丙烯之複合材料,探討複合材料之力學性質及熱性質。其方法系採用混煉法將玄武岩短纖維依照不同比例添加到泛用塑膠聚丙烯基材:過程乃使用雙螺桿混煉機,將玄武岩短纖維均勻混煉在聚丙烯基材內,經破碎造粒後由射出成型機製成玄武岩短纖維/熱塑性聚丙烯複合材料拉伸試片及壓縮試片,以測試並探討其拉伸性質、破損行為及壓縮性質;由TGA分析玄武岩短纖維/熱塑性聚丙烯複合材料之熱重損失及裂解溫度,以及DSC分析其吸熱與放熱時間軸,觀察玄武岩短纖維/熱塑性聚丙烯複合材料加熱過程中吸熱放熱與Tm之變化。 本實驗使用電腦伺服控制拉力試驗機,試驗方法符合CNS4396 K6423之標準,經測試結果顯示,拉伸彈性模數隨著玄武岩短纖維添加比例而增加,添加重量百分比為12%時複合材料具有最大的降伏應力,並提出以纖維增強材之體積百分比臨界值之假設,用以解釋利用玄武岩短纖維來增強熱塑性聚丙烯基材之複合材料,於其拉伸性質中具臨界值之存在。在壓縮強度試驗方面,使用電腦伺服控制壓縮強度試驗機,搭配特殊夾具;經測試結果顯示,在壓縮應變為2.5%,其壓縮強度亦隨著玄武岩短纖維添加比例而增加,在壓縮屈服應力則觀察到添加玄武岩短纖維重量百分比為12%時材料達到最佳屈服應力。在熱性質方面,由TGA及DSC分析顯示,加入玄武岩短纖維增強之複合材料能提高基材之熱裂解溫度,並有助熱穩定性之提昇。
Composites are a new material composed from two or more materials with different mechanical and chemical properties. They are normally formed by integrating organic and inorganic materials, taking the advantages of high stress, high hardness and thermal stability of inorganic ones, combined with the virtue of high toughness, the ability for processing of organic ones to produce a united material with characteristics of both. This study was to investigate the tensile properties and damage behavior of basalt staple fiber reinforced thermoplastic polypropylene composites. Various proportions of basalt staple fiber were added to the polypropylene, and the twin-screw mixer was applied for the evenly mixing result. Afterward, tensile specimens were obtained by using the injection molding machine. The decomposition temperature and weight loss rate of basalt staple fiber / polypropylene composite were analyzed by TGA. The variation in melting temperature was analyzed by DSC. A computer servo controlled tensile testing machine was used and the testing method was complied with the standard CNS4396 K6423. The results showed that the tensile elastic modulus increases with the increasing of basalt staple fibers. Also, while the added amount of basalt staple fiber was 12wt%, the proposed composite was with the largest yielding stress. For thermal properties, it was obviously that the inorganic fillers would raise the thermal decomposition temperature that would enhance its thermal stability.