Effects of phase behavior on mutual diffusion at polymer layers interface

✍ Scribed by Liang Yang; Tongchuan Suo; Yanhua Niu; Zhigang Wang; Dadong Yan; Howard Wang

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 381 KB
• Volume: 51
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2010.09.003

✦ Synopsis

Using oscillation mode of rheology and theoretical calculation, we have observed for the first time the crossover of mutual diffusion coefficient, D m , from high to low temperatures at the multiple layers interface of polymer films. A model which reflects a more realistic terminal state has been proposed to fairly fit the experimental data, by which the mutual diffusion coefficient D m can be determined. It is substantially found that the diffusion keeps proceeding for the multilayer system at the temperature lower than the critical temperature due to the requirement of a period of time for binodal compositions to reach. Moreover, it is found that the apparent activation energy, E d , derived from the Arrhenius relation of D m versus 1/T, increases surprisingly when the welding temperature is below 150 C, which relates closely to the effects of the phase behavior occurring in the two-phase region of the blend.