延伸加工對聚丙烯薄膜的超結構影響

Abstract

聚合物薄膜內部的超結構對於其成品的性質與產品性能影響甚大，了解並積極掌控薄膜內部的超結構是創新薄膜功能與改善性能的基礎。本研究探討聚丙烯薄膜延伸過程中的延伸溫度、延伸速率、延伸比率等控制參數對薄膜的超結構之影響，並調查膜內形成結構變化與延伸參數間的關聯性，以做為提升或創新薄膜物性的基礎。研究中採用本實驗室自行開發的延伸機構來對聚丙烯薄膜進行單軸延伸實驗，改變延伸溫度、延伸速率、延伸比率等參數，並利用偏光顯微鏡和掃描式電子顯微鏡對延伸後之薄膜實施結構觀察，探討這些參數對高分子薄膜的內部結構影響。研究結果顯示，聚丙烯薄膜經單軸延伸後會產生類似箏形結構以及破斷結構，延伸溫度和延伸倍率會影響其箏形結構和破斷結構的大小以及外觀。當延伸溫度越低時，整體結構大小較不一；反之當溫度越高，整體結構大小分佈較均勻。當延伸倍率越高時，箏形結構尺寸會較大且外型較細長。延伸實驗中發現延伸速度對試片內部結構的影響不大，整體結構不會隨著延伸速度的改變而有明顯的差異。

The super-structure in polymer can seriously affect products properties, and thus investigating super-structure properties is the key to improving polymer film quality. Polypropylene film was used to examine the effect of different extension temperature, extension speed and extension rate during polymer film extension process. This study use a lab developed extension device that can change the extension temperature, extension speed and extension rate, and observed the super-structure in polymer film using polarizing optical microscope and scanning electron microscope. The experiment shows that polypropylene film exhibits similar kite-shaped and damaged structure during extension process, and the extension temperature and extension rate impact the uniformity of kite-shaped and damaged structure, the structure of polymer film is more uniform under increasing extension temperature .The shape of kite-shaped structures are larger, longer and thinner under high extension rate; on the other hand, the effect of extension speed on polymer structure is not obvious during polymer film extension.