Structural Change of Regenerated Cellulose Fibers Caused by Water
Structural Change of Regenerated Cellulose Fibers Caused by Water
复制标题
水引起的再生纤维素纤维的结构变化
DOI：
10.2115/fiber.53.8_321
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
K. Okajima
中科院分区：
文献类型：
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作者：
C. Yamane;H. Ono;T. Hongo;M. Saito;K. Okajima
采用小角X射线衍射、比容和热激去极化电流（TSDC）分析方法研究了再生纤维素纤维在水作用下的结构变化，通过对不同回潮率的Cupro纤维的小角X射线衍射分析，发现在25°C、回潮率为40%时，纤维的横向结构发生长周期突变。并且在相同的回潮率下通过折光率测定法测定的Tg为25°C。当复水率小于4%时，TSDC γ1弛豫峰强度随复水率的增大而减小。百分之五当复水率大于4时，随着复水率的增加，TSDC β1松弛减小，TSDC β2松弛增大。百分之五由此推断，在4 ℃以下的回潮率下，由TSDC γ1弛豫确定的疏水区可能发生了结构形成和局部分子运动。当回潮率大于4%时，TSDC β1区的分子发生局部重排，进入TSDC β2区。纤维素主链的微布朗运动在30 ℃时释放，在室温下，纤维素纤维的吸水率可达40%，从而导致纤维素纤维的长周期突变和宏观溶胀。
Structural change of regenerated cellulose fibers caused by water was investigated with the small angle X-ray, the specific volume and thermally stimulated depolarized current (TSDC) analyses.From the small angle X-ray measurement of Cupro fiber with various water regain, the sudden change of long period for lateral direction was detected at 40% of water regain at 25°C. And the Tg determined by dilatometry at the same water regain was 25°C. The peak intensity of TSDC γ1 relaxation decreased with increase in water regain when the water regain was under 4_??_5%. TSDC β1 relaxation decreased while TSDC β2 increased with increase in water regain when the water regain was above 4_??_5%. From these findings, it was concluded that the structural formation followed by the local molecular movement may be occurred in hydrophobic domain assigned by TSDC γ1 relaxation at the water regain under 4_??_5%, and then the local molecular rearrangement from TSDC β1 region to TSDC β2 region was also occurred at the water regain above 4_??_5%, and finally the micro-Brownian motion of cellulose main chain assigned by tan δα2 relaxation was released at 30_??_40% of water regain at room temperature which brings the sudden change in long periodicity and the macroscopical swelling of the regenerated cellulose fibers.