雷射光與冷卻速率對熱壓成形之聚丙烯的高次結構影響

Abstract

高分子材料在一般射出成形或熱壓成形過程中，主要的成形參數有溫度、壓力以及時間等，但對於現在要求提高材料的功能性而言略顯不足。近年來研究顯示，成形中添加外場效應會使高分子材料的高次結構產生變化，所以本研究嘗試對熱壓成形中的高分子材料施以短波長雷射（λ=405nm）照射，探討其對材料的高次結構產生之影響，以做為生產具有特殊結構的功能性材料的參考資料。 由實驗結果發現熱壓成形品內部會分成三層不同的構造，大致上類似射出成形品的表皮層、中間層以及核心層，各層的厚度比約為1：1.7：7.7。熱壓時降低冷卻速率，會使高分子有較多時間摺疊分子鏈，而使內部高次結構球晶變大及數量增多。熱壓時添加雷射光照射，雷射光所提供的能量亦可促進球晶的成核與成長，其效果與施加的時間點以及照射時間長短有關。

In the process of injection molding or hot-embossing, the main parameters of polymer are temperature, pressure and time, but which are not enough for enhancing the material function. Recently, the research shows the effects of the extra energy field made the substructure change. Therefore, this study attempt to irradiate the hot-embossing of polymeric materials with short-wavelength laser (λ = 405nm), which explore the impact of the material of superstructure production as the reference for producing the functional material with special structure. According to the experimental results, the hot-embossing interior will be molded into the different three layers: the surface layer, the middle layer and the core layer. The thickness proportion of each layer is about 1 : 1.7 : 7.7. In the process of the hot embossing, to lower the cooling rate, the macromolecule made more time fold polymer molecular chain, and then the spherulite would become bigger and greater. To irradiate with laser, whose capability promote the spherulite into nucleation and growth, the effects depend on the imposed and exposure time.