High-rate crystallization of polycarbonate in spincast thin film

スピンキャストしたポリカーボネイト薄膜中の結晶化

阿多 誠介*; 岡 壽崇   ; He, C.-Q.*; 大平 俊行*; 鈴木 良一*; 伊藤 賢志*; 小林 慶規*; 扇澤 敏明*

Ata, Seisuke*; Oka, Toshitaka; He, C.-Q.*; Odaira, Toshiyuki*; Suzuki, Ryoichi*; Ito, Kenji*; Kobayashi, Yoshinori*; Ougizawa, Toshiaki*

スピンキャスト法で作製したbisphenol-Aポリカーボネイト薄膜の表面形状をAFMによって調べた。スピンキャストした30nmの薄膜を200Cで熱処理したところ、高い結晶化度のサンプルが得られた。陽電子消滅寿命測定の結果から、この薄膜の自由体積空孔サイズは、バルクのそれよりも大きいことが明らかになった。

Surface morphology of bisphenol-A polycarbonate (BAPC) thin films with thickness ranging from 30 to 1000 nm on silicon substrates was studied by atomic force microscopy (AFM). The films were prepared by spincasting from 1,2-dichloroethane solutions of 0.25-5.0 wt % BAPC. Even though longer annealing than 250 h was necessary for complete crystallization for bulk BAPC, high crystallinity was observed for 30 nm thick film after annealing at 200 C for 48 h in vacuum. Positron annihilation lifetime spectroscopy (PALS) measurements showed that the free volume hole size in 30 nm thick film was larger than that of bulk at 200 C. Comparison of the BAPC concentration in the precursor solution with the overlap concentration suggests that the high crystallinity of the 30 nm BAPC film is due to less entangled chains caused by rapid removal of the solvent from the dilute solution.