聚苯乙烯（Polystyrene，縮寫PS）是指由苯乙烯單體經自由基加聚反應合成的聚合物，日文名稱為ポリスチレン。它是一種有色透明的熱塑性塑料，具有高于100℃的玻璃轉化溫度，因此經常被用來制作各種需要承受開水的溫度的一次性容器，以及一次性泡沫飯盒等。

聚苯乙烯玻璃化溫度80～90℃，非晶態密度1.04～1.06克/立方厘米，晶體密度1.11～1.12克/立方厘米，熔融溫度240℃，電阻率為1020～1022歐·厘米。導熱系數30℃時0.116瓦/(米·開)。通常的聚苯乙烯為非晶態無規聚合物，具有優良的絕熱、絕緣和透明性，長期使用溫度0～70℃，但脆，低溫易開裂。此外還有全同和間同以及無規立構聚苯乙烯。全同聚合物有高度結晶性，間同聚合物有部分結晶性。


HIPS 臺灣奇美 PH-88S 華南代理 分類

聚苯乙烯（PS）包括普通聚苯乙烯，發泡聚苯乙烯（EPS)，高抗沖聚苯乙烯（HIPS）及間規聚苯乙烯（SPS）。普通聚苯乙烯樹脂，無臭，無色的透明顆粒，似玻璃狀脆性材料，其制品具有極高的透明度，透光率可達90%以上，電絕緣性能好，易著色，加工流動性好，剛性好及耐化學腐蝕性好等。普通聚苯乙烯的不足之處在于性脆，沖擊強度低，易出現應力開裂，耐熱性差及不耐沸水等。
屬性

普通聚苯乙烯樹脂屬無定形高分子聚合物，聚苯乙烯大分子鏈的側基為苯環，大體積側基為苯環的無規排列決定了聚苯乙烯的物理化學性質，如透明度高.剛度大.玻璃化溫度高，性脆等。可發性聚苯乙烯為在普通聚苯乙烯中浸漬低沸點的物理發泡劑制成，加工過程中受熱發泡，專用于制作泡沫塑料產品。高抗沖聚苯乙烯為苯乙烯和丁二烯的共聚物，丁二烯為分散相，提高了材料的沖擊強度，但產品不透明。間規聚苯乙烯為間同結構，采用茂金屬催化劑生產，發展的聚苯乙烯新品種，性能好，屬于工程塑料。



HIPS 臺灣奇美PH-88S  華南代理成型性能

無定形料，吸濕小，不須充分干燥，不易分解，但熱膨脹系數大，易產生內應力。流動性較好，可用螺桿或柱塞式注射機成型。宜用高料溫，高模溫，低注射壓力，延長注射時間有利于降低內應力，防止縮孔、變形.。 可用各種形式澆口，澆口與塑件圓弧連接，以免去處澆口時損壞塑件。脫模斜度大，頂出均勻。塑件壁厚均勻，不帶鑲件，如有鑲件應預熱。
1.吸水性極小，成型前可不干燥。模溫30-60度，料溫140-200度。
2.性脆易裂，熱膨脹系數大，易產生內應力。
3.流動性較好，應注意模具間隙，防止縮孔、飛邊。
4.宜采用高料溫、高模溫、低注射壓力，延長注射時間有利于降低內應力，防止縮孔、變形，但料溫過高，容易出現銀絲，料溫低或脫模劑多則透明性差。
5.可采用各種形式的澆口，脫模斜度宜大，頂出力均勻，以防開裂。
6.塑件壁厚均勻，不帶嵌件，各面應圓弧連接，不宜有缺口、尖角。

Wasn't it odd that she didn't know who she was? And wasn't it unreasonable that she hadn't been allowed to have any say in what she would look like? Her looks had just been dumped on her. She could choose her own friends, but she certainly hadn't chosen herself. She had not even chosen to be a human being.

But if space had come from something else, then that something else must also have come from something. Sophie felt she was only deferring the problem. At some point, something must have come from nothing. But was that possible? Wasn't that just as impossible as the idea that the world had always existed?

They had learned at school that God created the world. Sophie tried to console herself with the thought that this was probably the best solution to the whole problem. But then she started to think again. She could accept that God had created space, but what about God himself? Had he created himself out of nothing? Again there was something deep down inside her that protested. Even though God could create all kinds of things, he could hardly create himself before he had a "self" to create with. So there was only one possibility left: God had always existed. But she had already rejected that possibility! Everything that existed had to have a beginning.