κ-卡拉胶凝胶的力学行为研究

A STUDY ON MECHANIC BEHAVIOR OF κ-CARRAGEENAN BY ADSP

利用溶胀性能自动检测仪,通过测定κ-卡拉胶(KC)凝胶的压缩形变及相应的应力得到其压缩模量Ee,并考察了介质(水、硅油和空气)、交联度和KC浓度对Ee的影响。结果表明,Ee值较小,仅在104Pa数量级,并随KC浓度增加而增大;Ee对介质环境十分敏感,按在水、硅油及空气中的顺序递减;Ee与交联度关系更依赖于介质:在空气中基本成正比,在硅油中高交联度端略偏离直线,而在水中因高交联度端Ee下降而出现峰值。“偏离”与“峰值”是典型软质材料的体现,与Ee值较小相符,并有凝胶溶胀程度愈大,软质材料特性愈明显的规律。

Thermoreversible hydrogels of κ-carrageenan(KC)were studied by an instrument for automatic determination of swelling of polymer (ADSP). The compressive modulus E_e and the influence of both cross-linking degree and KC concentration on Ee of KC gels in three mediums (air, silicon oil and water) were studied separately. E_e is very sensitive to medium and increases following the concentration of KC in all three mediums proportionally. And E_e is approximately proportional to cross-linking degree in air; but in silicon oil, a small deviation to the linear relationship occurs in high cross-linking degree region; furthermore, in water, E_e has a different rule from that in silicon oil and decreases in high cross-linking degree region gradually. As a result, peak value (PV) of E_e appears. Deviation and PV are characteristics of typical soft materials, which agree well with the small value of E_e of KC hydrogels.