高分子固体レオロジーの構造論的研究

概要

論文の詳細を見る
A new concept of the nature of the crystalline relaxation (αc) mechanism of high-density polyethylene was proposed. This concept is based on the mechanical properties observed in the αc temperature range for as-grown single crystals mats and samples of bulk crystallized material. The decomposition of the αc multiple relaxiation process into the α1-and α2-processes was carried. It was concluded that the α1-and α2-relaxiation mechanisms might be attributed to the deformation of intermosaic block region and that of interlamellar crystalline region, respectively. Threfore, the α1 process was strongly affected by slight elongation and fatigue cycling of the sample. The surface relaxiation process for the monodisperse polystyrene (PS) films with different number-average molecular weight, Mn was investigated on the basis of lateral force microscopy (LFM) and scanning viscoelasticity microscopy (SVM). SVM measurements showed that the surface of the monodisperse PS film with Mn lower than 30 k was in a glass-rubber transition state or in a rubbery state even at 293 K, even though the bulk Tg was far above 293 K. It was revealed from the temperature-dependent LFM that the magnitude of activation energy for the surface αa- relaxiation process is almost half as much as that for the bulk one. The molecular weight dependences of the Tgs for the monodisperse PS film with various chain end groups were also investigated on the basis of temperature-dependent SVM measurement. The Tgs was strongly dependent on a difference of surface free energy between chain end group and main chain.
日本レオロジー学会の論文
1999-12-01

高分子固体レオロジーの構造論的研究

スポンサーリンク

概要

著者

関連論文

スポンサーリンク