TY - JOUR
T1 - Self-assembling polycondensation for preparation of poly(p-oxybenzoyl-alt-p-mercaptobenzoyl) whisker
AU - Kobashi, Kazufumi
AU - Kimura, Kunio
AU - Yamashita, Yuhiko
AU - Uchida, Tetsuya
AU - Sakaguchi, Yoshimitsu
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2003/6/17
Y1 - 2003/6/17
N2 - Self-assembling polycondensation was examined to prepare the whisker of poly(p-oxybenzoyl-alt-mercaptobenzoyl). Polymerizations were carried out in liquid paraffin (LPF) and aromatic solvents such as Therm S 800 and 1000 at 300°C for 6 h. Polymerization concentration was 1.0 wt/vol%. The whisker was not obtained by the random copolymerization of p-acetoxybenzoic acid and S-acetyl-4-mercaptobenzoic acid at the molar ratio of 0.5 in feed. However, the whiskers were successfully prepared by the polymerization of S-(4-acetoxybenzoyl)-4-mercaptobenzoic acid (OS) and 4-(S-acetyl-4-mercaptobenzoyl)oxybenzoic acid (SO). The whisker prepared from OS (POS) in LPF was 18 μm in average length and 0.4 μm in average width, and that from SO (PSO) was slightly longer than POS. The whiskers prepared in aromatic solvents were much longer than those in LPF, for which the length was 36-49 μm. These whiskers consist of the alternating polymer chains, and the polymer chains align along the long axis of the whisker. The sequence regularity enhanced the crystallizability of the oligomers, and this led to the formation of whiskers. The oligomer formation rate was much higher than that of transesterfication reaction rate, and this large difference in these two rates made the oligomer precipitate with maintaining the alternating sequence. Further polymerization occurred in the crystals, and the whiskers having the alternating sequence were finally completed. The difference in the two rates increased with the decrease of the miscibility between the oligomer and the solvent, and therefore, OS and LPF were more advantageous to maintain the alternating sequence.
AB - Self-assembling polycondensation was examined to prepare the whisker of poly(p-oxybenzoyl-alt-mercaptobenzoyl). Polymerizations were carried out in liquid paraffin (LPF) and aromatic solvents such as Therm S 800 and 1000 at 300°C for 6 h. Polymerization concentration was 1.0 wt/vol%. The whisker was not obtained by the random copolymerization of p-acetoxybenzoic acid and S-acetyl-4-mercaptobenzoic acid at the molar ratio of 0.5 in feed. However, the whiskers were successfully prepared by the polymerization of S-(4-acetoxybenzoyl)-4-mercaptobenzoic acid (OS) and 4-(S-acetyl-4-mercaptobenzoyl)oxybenzoic acid (SO). The whisker prepared from OS (POS) in LPF was 18 μm in average length and 0.4 μm in average width, and that from SO (PSO) was slightly longer than POS. The whiskers prepared in aromatic solvents were much longer than those in LPF, for which the length was 36-49 μm. These whiskers consist of the alternating polymer chains, and the polymer chains align along the long axis of the whisker. The sequence regularity enhanced the crystallizability of the oligomers, and this led to the formation of whiskers. The oligomer formation rate was much higher than that of transesterfication reaction rate, and this large difference in these two rates made the oligomer precipitate with maintaining the alternating sequence. Further polymerization occurred in the crystals, and the whiskers having the alternating sequence were finally completed. The difference in the two rates increased with the decrease of the miscibility between the oligomer and the solvent, and therefore, OS and LPF were more advantageous to maintain the alternating sequence.
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U2 - 10.1021/ma030046n
DO - 10.1021/ma030046n
M3 - Article
AN - SCOPUS:0038236397
VL - 36
SP - 4268
EP - 4275
JO - Macromolecules
JF - Macromolecules
SN - 0024-9297
IS - 12
ER -