【摘 要】
:
Ultra high molar mass polyethylene (UITPE) powder as polymerized in a slurry process has been studied, in its nascent state, after recrystallization on rapid co
【机 构】
:
Department of Materials Science,China Textile 4cademy,Institute of Chemistry,Changchun Institute of
论文部分内容阅读
Ultra high molar mass polyethylene (UITPE) powder as polymerized in a slurry process has been studied, in its nascent state, after recrystallization on rapid cooling from the melt and after hot compression molding to a film, by DSC,effect ofannealing the recrystallized specimen at 120~I30℃, morphology by polarizing optical microscopy and small angle X-ray scattering. Based on the experimental results obtained the macromolecular condensed state of the nascent UHPE powder is a rare case of a multi-chain condensed state of non-interpenetrating chains, involving interlaced extended chain crystalline layers and relaxed parallel chain amorphous layers. On melting, a nematic rubbery state of nanometer size domain resulted. The nematic-isotropic transition temperature was judged from literature data to be at least 220°C, possibly higher than 300 °C, the exact temperature is however not sure because of chain degradation at such high temperatures. The recrystallization process from the melt is a crystallization from a nematic rubbery state. The drop of remelting peak temperature by 10 K of the specimen recrystallized from its melt as compared to the nascent state has its origin in the decrease both of the crystalline chain stem length and of the degree of crystallinity. The remelting peak temperature could be returned close to that of the nascent state by annealing at 120~130°C.
其他文献
In this paper, the fracture process of a unidirectional CF/SiC single edge-notched beam (SENB) under three-point bending (TPB) is studied by means of macro/micr
Ind2Y(μ-Et)2A1Et2 and Ind2LnN(i-Pr)2 (Ln = Y, Yb) were used as a single-component catalyst for the polymerization of acrylonitrile (AN) respectively. The regul
To evaluate the sperm motility stimulating activity of a sulfono glycolipid (S-ACT-l) isolated from Gelidiella acerosa, a Sri Lankan marine red algae. Methods:
The structural analysis of two PP/PE copolymer samples, I and 2, was conducted by using 13C-NMR, GPC and crystallization segregation DSC (CSDSC) techniques. A p
The difference of τB and τ∧b indicates the role of the light flavors. We calculate the lifetimes ofB-meson and ∧b based on the weak effective Hamiltonian wh
本文提出一种“合治”的汉字结构观:将文字结构的硬件和软件二元要素看作是一种互动的关系,二者之间相互影响、相互渗透、相互转化,强调在二者间的互动关系中研究其中的一个
By using the logarithmic strain, the finite deformation plastic theory, corresponding to the infinitesimal plastic theory, is established successively. The plas
Crystalline morphology in a series of CH3-substituted main chain thermotropic aromatic polyesters with even and odd numbered methylene spacers has been studied
γ-Alumina-supported copper-manganese oxide was prepared by impregnation and used for carbon monoxide hydrogenation. The Cu-MnOx/γ-Al2O3 catalysts exhibit high
The structure of the complex bis-(o-vanillin)di-pyridine nickel(Ⅱ)([ Ni X-ray analysis.The crystal data are as follows: Monoclinic,P21/n,a=12.273(1),b=17.4700.