最新刊期
      卷 0 ， 期 0 ， 2020
      • Qin-wei YIN,Shi-yu FU,Huai-yu ZHAN
        Vol. 20, Issue 5, Pages: 1-11(2007) DOI: 10.14028/j.cnki.1003-3726.2007.05.001
        摘要：For the last twenty years, research interested into the use of natural biopolymers, which was a way of preventing environment pollution, putting into effect of green chemistry and development of human being in perfect harmony. Gluten was a byproduct of cereal industry which was abundant, biodegradable and reproducible biopolymer. Because of its viscoelasticity, extensibility, film-forming and thermosetting, people paid more attention to gluten, which could be used as raw materials for polymer products in technical applications as well as food additives. The present paper reviewed the composition of wheat gluten, the principles and methods for chemical modification, physical changing and enzyme reaction of wheat gluten. Besides, the application and prospect of gluten was also described.  
        关键词：Renewable resources;Gluten;Modification;Application   
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        发布时间：2022-09-18
      • Peng GAO,Xiao-xia GUO,Hong-jie XU,Jian-hua FANG
        Vol. 20, Issue 5, Pages: 12-22(2007) DOI: 10.14028/j.cnki.1003-3726.2007.05.002
        摘要：This article reviews recent progress in the development of sulfonated hydrocarbon polymers as electrolyte membrane materials for fuel cell application. The relationship between polymer structure and the proton conductivity and water stability was discussed in detail. Sulfonated polymer membranes with high ion exchange capacities (IECs) generally have high proton conductivities at high relative humidities (> 80 %) but often suffer from their poor water stability because of over-swelling of the membranes. Some sulfonated polyimides and other sulfonated polymers with both high proton conductivity and water stability have been successfully developed and these membranes showed better fuel cell performance than the widely used sulfonated perfluoropolymer Nafion. However, there is still a common problem associated with all the sulfonated hydrocarbon polymers developed so far that their proton conductivities are too low (much smaller than 0.01 S° cm-1 ) at low relative humidities (< 30 %) and this needs to be solved to meet the requirement for practical use. In addition, membrane stability including water stability and radical oxidative stability at high temperature is also needed to be further improved for medium temperature (150 ~ 200 ℃) fuel cell application.  
        关键词：Fuel cells;Proton exchange membrane;Sulfonated polymer;Synthesis;Proton conductivity   
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        发布时间：2022-09-18
      • Tao YU,Du-jin WANG,Fo-song WANG
        Vol. 20, Issue 5, Pages: 23-34(2007) DOI: 10.14028/j.cnki.1003-3726.2007.05.003
        摘要：Aliphatic polycarbonate copolymers are a new kind of completely biodegradable materials.Since the copolymerization of carbon dioxide and epoxides was first employed by Inoue et al.in1969,many achievements have been made in the field of carbon dioxide fixation as completely biodegradable materials.This review summarizes the latest progress in the catalyst preparation for the copolymerization of carbon dioxide and epoxide as well as the reaction mechanism.The relationship between structure and properties of aliphatic polycarbonate is discussed.The applications of this kind of biodegradable materials in various fields are also introduced briefly.  
        关键词：Aliphatic polycarbonate;Biodegradable;Copolymerization;Structure-property relationship   
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        发布时间：2022-09-18
      • Jian-cai DAI,Ying SHI,Xiao-li ZHAN,Feng-qiu CHEN
        Vol. 20, Issue 5, Pages: 35-40(2007) DOI: 10.14028/j.cnki.1003-3726.2007.05.004
        摘要：Miniemulsion polymerization is characterized by droplet nucleation. Not only nucleation mechanism but also kinetics with different costabilizer, such as cetyl alcohol(CA), hexadecane(HD), polymeric costabilizers and monomeric costablizer, of radical polymerization in miniemulsion are reviewed in details.  
        关键词：Miniemulsion polymerization;Droplet nucleation;Kinetics   
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        发布时间：2022-09-18
      • Qi-ye WU,Peng LI,Jing-xia MU,Hai-jun FAN,Na ZHANG,Xin WANG
        Vol. 20, Issue 5, Pages: 41-47(2007) DOI: 10.14028/j.cnki.1003-3726.2007.05.005
        摘要：The flow curves, extrudate distortions, extrusion pressure variety and the characters of viscoelasticity of linear and branched polyolefine melts in high speed extrusion was investigated by a double capillary rheometer of constant speed type. The unstable flow behaviors and the trouble headstream of different melts were discussed. The results indicate that there are three kinds of trouble headstreams in high speed extrusion flow field, such as the destabilization on die entrance, on die wall, and on die exit. Branched polymer is easily disturbed by the destabilization on die entrance, which will cause a irregular extrudate fracture ;while the linear polymer is easily disturbed by the destabilization on die wall, which will cause an extrusion pressure oscillation and a regular extrudate distortion. The sharkskin-like distortion is caused by an oscillatory destabilization on die exit.  
        关键词：Polyolefine melts;Capillary rheometer;Unstable flow;Trouble headstream   
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        发布时间：2022-09-18
      • Xiao-na HOU,Zhao-yang WANG,Hai-jun ZHAO,Xiong-wu LI,Lü-yin ZHENG
        Vol. 20, Issue 5, Pages: 48-53(2007) DOI: 10.14028/j.cnki.1003-3726.2007.05.006
        摘要：In order to improve the degradation rate and cellular affinity of polylactic acid (PLA),more and more importance has been attached to the modification of PLA by amino acids.As an important modification method, copolymer poly(lactic acid-co-amino acid) (PLAA) was usually synthesized via the ring opening polymerization of cyclic intermediates,especially morpholine-2,5-dione.At the same time,the properties and applications of different kinds of PLAA and PLAs modified by amino acid are reviewed.It is necessary to reduce the synthetic cost of PLAAs to extend their applications in the future.Since the cyclic intermediates,including morpholine-2,5-dione were produced from lactic acid (LA) and amino acid (or its derivatives),the direct economic and effective syntheses of PLAAs using LA and amino acid as starting materials should be noticeable.  
        关键词：Amino-acid;Poly(lactic acid) (PLA);Modification;Morpholine-2,5-dione;Poly(lactic acid-coamino acid) (PLAA)   
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        发布时间：2022-09-18
      • Wei WANG,Qi-yun DU
        Vol. 20, Issue 5, Pages: 54-59(2007) DOI: 10.14028/j.cnki.1003-3726.2007.05.007
        摘要：Hollow fiber composite membrane is one of separation membranes which were prepared from two (or more) kinds of materials through special techniques.The membrane combines the structure characterizes of a hollow fiber (such as self-support) with the separation properties of a composite membrane (such as high-selectivity and high-permeability).At first,materials (or adding materials) of both the composite lay and the substrate membrane were summarized in this article.Then based on the structure properties of the membrane,the hollow fiber composite membranes were classified simply.Preparation technologies and equipments of the hollow fiber membranes were discussed emphatically.At last,the development of the hollow fiber composite membranes in some fields such as pervaporation,gas separation and nanofiltration were described in detail,and some problems deserving further research in this field were discussed too.  
        关键词：Hollow fiber composite membrane;Pervaporation;Gas separation;Nanofiltration;Development   
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        发布时间：2022-09-18
      • Hui ZHANG,Tian-zhi YU,Duo-wang FAN
        Vol. 20, Issue 5, Pages: 60-64(2007) DOI: 10.14028/j.cnki.1003-3726.2007.05.008
        摘要：Chitosan nanopaticles are an active reseach area in recent years.As the research progressing,lots of Chitosan-based nanocomposites have been prepared.The preparation is relative with the interactions,so it is necessary to study the interactions (physical or chemical) on early stage of chitosan-based nanocomposites development.This article summarizes the research of chitosan-based nanocomposites involving in various interactions including electrostatic interaction,covalenctly crosslinking,adsorption,hydrogen bonding processes,and their application.Due to the excellent biological compatible,these nanocomposites are applied to drug delivery systems in brief.  
        关键词：Chitosan;Nanocomposites;Interaction   
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        发布时间：2022-09-18
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