TY - JOUR
T1 - Elevation of the flow temperature of gels formed by nano fibers of Poly(L-lactic acid) by surface crystallization induced by block copolymers
AU - Matsuda, Yasuhiro
AU - Fukui, Takahiro
AU - Ishima, Shun ich
AU - Takahara, Atsushi
AU - Tasaka, Shigeru
N1 - Funding Information:
The authors thank Prof. Nobuyuki Mase at Department of Applied Chemistry and Biochemical Engineering, Shizuoka University for allowing us to use the polarimeter. This work was performed under Cooperative Research Program of “ Network Joint Research Center for Materials and Devices ” (No. 20183073 and 2019130 7).
Funding Information:
The authors thank Prof. Nobuyuki Mase at Department of Applied Chemistry and Biochemical Engineering, Shizuoka University for allowing us to use the polarimeter. This work was performed under Cooperative Research Program of ?Network Joint Research Center for Materials and Devices? (No. 20183073 and 20191307).
PY - 2019/10/24
Y1 - 2019/10/24
N2 - Block copolymers of poly (L-lactic acid) (PLLA) and polystyrene with different lengths of PLLA blocks entered into the network structures of PLLA gels formed with complex crystals with solvent molecules. The induced changes of the structure and the flow temperature of the gels were investigated to elucidate the mechanism of the block copolymers to elevate the flow temperature. The block copolymer with shorter PLLA blocks elevated the flow temperature of the PLLA gels from 40 °C to 70 °C by immersing in the block copolymer solution with a lower concentration (0.5 wt%). For the block copolymers with longer PLLA blocks, higher concentrations (2.0 wt%) were necessary to elevate the flow temperature to 70 °C, and the flow temperature was elevated to 80 °C by immersing more concentrated solutions (3.0 wt%). This behavior can be explained by assuming that the surface crystallization of PLLA fibers induced by the block copolymers elevated the flow temperature to 70 °C, and the reinforcement of the fibers by spherical structure of the block copolymers elevated the flow temperature to 80 °C, was proposed based on the experimental results.
AB - Block copolymers of poly (L-lactic acid) (PLLA) and polystyrene with different lengths of PLLA blocks entered into the network structures of PLLA gels formed with complex crystals with solvent molecules. The induced changes of the structure and the flow temperature of the gels were investigated to elucidate the mechanism of the block copolymers to elevate the flow temperature. The block copolymer with shorter PLLA blocks elevated the flow temperature of the PLLA gels from 40 °C to 70 °C by immersing in the block copolymer solution with a lower concentration (0.5 wt%). For the block copolymers with longer PLLA blocks, higher concentrations (2.0 wt%) were necessary to elevate the flow temperature to 70 °C, and the flow temperature was elevated to 80 °C by immersing more concentrated solutions (3.0 wt%). This behavior can be explained by assuming that the surface crystallization of PLLA fibers induced by the block copolymers elevated the flow temperature to 70 °C, and the reinforcement of the fibers by spherical structure of the block copolymers elevated the flow temperature to 80 °C, was proposed based on the experimental results.
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U2 - 10.1016/j.polymer.2019.121768
DO - 10.1016/j.polymer.2019.121768
M3 - Article
AN - SCOPUS:85072516434
SN - 0032-3861
VL - 181
JO - Polymer
JF - Polymer
M1 - 121768
ER -