Microphase structures and ~(13)C NMR relaxation parameters in ultrahigh molecular weight polyethylen

• 作 者: 朱清仁 洪昆仑 鲁非 戚嵘嵘 庞文民 周贵恩 宋名实
• 机 构: Structure Research Laboratory,University of Science and Technology of China,Hefei 230026,China,Resea
• 出 处: Science in China(Series B)
• 发表日期: 1995年11期
• 关键词: polyethylene relaxation crystalline modulus chains amorphous brief ultrahigh dra

The phase transformations in ultrahigh molecular weight polyethylene(UHMWPE)gel-filmsupon superdrawing have been studied by X-ray diffraction and high resolution solid state ~(13)C NMR.Themorphological change and molecular motions in the crystalline phase,amorphous phase and interphase are dis-cussed according to the ~(13)C nuclear relaxation time(T_(1c),T_(2c)results.A brief interpretation to the three orfour T_(1c)values in the crystalline phase is presented.It is found that the component with the highest T_(1c)(T_(1c)~α)plays a key role in the forming of ’Shish-Kebab’ microfibril which determines the sample strength andmodulus,namely,the greater the T_(1c)~α,the higher the modulus and strength of the drawn UHMWPEgel-film.These results support the ’Shish-Kebabs’ model in crystalline polymers.

The phase transformations in ultrahigh molecular weight polyethylene (UHMWPE) gel-film superfasting have been studied by X-ray diffraction and high resolution solid state ~ (13) C NMR. The morphological change and molecular motions in the crystalline phase, amorphous phase and interphase are C-relaxation time (T_ (1c), T_ (2c) results. A brief interpretation to the three orfour T_ (1c) values ​​in the crystalline phase is presented. It is found that the component with the highest T_ (1c) (T_ (1c) ~ α) plays a key role in the forming of ’Shish-Kebab’ microflexure which determines the sample strength and module, namely, the greater the T_ (1c) higher modulus and strength of the drawn UHMWPEgel-film.These results support the ’Shish-Kebabs’ model in crystalline polymers.