最新刊期
卷 28 ， 期 2 ， 2015
- 摘要：High isotactic polybutene-1 was well known for its excellent properties. The catalytic features and the composites of Ziegler-Natta catalysts and metallocene catalysts used for the synthesis of high isotactic polybutene-1(H-iPB) were reviewed. The polymerization processes including slurry polymerization, liquid bulk polymerization(homogeneous phase and heterogeneous phase), and vapor polymerization for H-iPB synthesis were introduced in detail. The features of those three polymerization processes, especially the advantages and disadvantages of liquid bulk polymerization process were illustrated. The development tendency of high isotactic polybutene-1 polymerization process in future was pointed out.关键词：High isotactic polybutene-1;Slurry polymerization;Liquid bulk polymerization;Vapor polymerization
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发布时间：2022-09-18 - 摘要：Shape memory polymers (SMPs) have attracted extensive attention because they have several advantages: light; low cost; highly recoverable deformation; high shape fixity ratio; designable structure and diverse stimulus ways, etc. Compared with other methods, polymer blending is believed to be more convenient for fabricating SMPs. For amorphous/crystalline polymer blends, the crystalline behavior is the key to the shape memory performances. Based on the current research status in this area,this paper presents a review of the influence of the crystallinity, crystal size and crystal orientation on shape memory properties of polymer blends.关键词：Shape memory;Blend;Crystallinity;Crystal size;Crystal orientation
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发布时间：2022-09-18 - 摘要：Electrospinning is one of the important methods for preparing form-stable phase change composite materials. The paper reviews the research progress of form-stable phase change composite materials by electrospinning. The preparation methods mainly include solution electrospinning, solution-solution coaxial electrospinning, melt-solution coaxial electrospinning and physical adsorption of electrospun nanofibrous mats, etc. During electrospinning, the general used solid-liquid phase change materials (e.g., aliphatic long-chain alkanes, soy wax, fatty acids and their binary fatty acid eutectics, fatty acid esters and polyethylene glycol, etc) and supporting materials (e.g., cellulose acetate (CA), polyethylene terephthalate (PET), polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), poly(dl-lactide) (PLA), polyurethane (PU), polyamide 6 (PA6), polyacrylonitrile (PAN) and the derived carbon nanofibers, etc) are also summarized.关键词：Electrospinning;Form-stable phase change composite materials;Nanofibers;Preparation methods
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发布时间：2022-09-18 - 摘要：As the polycarboxylate-type high performance superplasticizer(PCEs) has the excellent performance on the water reducing, nowadays it has been one of the hottest researches on the concrete admixtures. In the paper, four different molecular structures of PCEs were detailed specified basing on the development history. Meanwhile, there is a contrast about the synthesis of four PCEs and the pros and cons of their performance. According to the problems focused on its poor abilities, such as slump, shrinkage rage, early strength, air entraining and sensibility, which have been studied both at home and abroad. And varieties of feasible solutions have been provided. At last, other aspects of PCEs, such as environmental protection, material price and market demand, have also been briefly described and prospected in the paper.关键词：Water reducer;Polycarboxylate;Molecular structure;Modified
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发布时间：2022-09-18 - 摘要：Polyaniline is one type of conductive polymeric materials, which could effectively postpone the corrosion of metal substrate by means of barrier and passivation effects when applied in anti-corrosive coatings. In this article, the fundamental characteristics of polyaniline materials and their anti-corrosive mechanisms were introduced, and the performances of different polyaniline application systems were reviewed.关键词：Polyaniline;Conductive polymer;Anti-corrosive;Dope;Composite
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发布时间：2022-09-18 - 摘要：Materials in natural polymers have weak allograft antigenicity, good compatibility and biodegradable and can promote cell adhesion, growth and proliferation, Such as chitosan, silk fibroin and collagen. Compare to synthetic polymer, the natural polymers almost do not contain organic solvent and initiators. It showed high biological safety and is preferential to use in cell culture matrix raw materials. In recent years, along with the development of biotechnology, new functions of these natural polymer are being found and valued. In this paper, the physical and chemical properties of natural polysaccharide and protein as well as their application as cell culture matrix are reviewed in details, and the existing problems were described and the development directions of these materials was forecasted.关键词：Natural polymers;Biocompatibility;Cell culture matrix
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发布时间：2022-09-18 - 摘要：In this paper, polyethylene (PE) pipes with three diameters were prepared via die rotation extrusion and a thorough research was done on their microstructures and properties. The experimental results showed that compared to shish-kebab parallel to axial direction of PE pipe prepared by convention extrusion, hoop drag flow caused by die rotation was superimposed on axial traction flow during die rotation extrusion and the polymer flow direction was off the axial direction of the pipe so that the direction of shish-kebab alignment deviated from the axial direction to increase hoop orientation of the PE pipe and improve significantly the hoop strength and suppress the crack growth along the axial direction. With the increasing diameter of the PE pipe, hoop linear velocity went up at the same angular velocity and the angles of shish kebab deviated from the axial direction became larger so more improvement was achieved in the PE pipe with the longer diameter.关键词：Rotation extrusion;Polyethylene pipe;Morphology;Shish-kebab;Orientation
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发布时间：2022-09-18 - 摘要：The non-spherical polystyrene (PS) particles were synthesized via soap-free emulsion polymerization with styrene (St), divinyl benzene (DVB), methacryloyloxy trimethyl ammonium chloride (DMC) as monomers in ethanol and water mixed medium. The structure, morphology, particle size and surface potential were analyzed by FT-IR, TEM, laser particle size and potential analyzer. The results indicate that the PS particles contain three kinds of structural unit and have non-spherical morphology; With the increase of dosage of DVB, PS particle morphology tend to be more spherical, particle size and monodisperse coefficient increase gradually; With the increase of DMC dosage, PS particle size increase, monodisperse coefficient decreases, surface Zeta potential also gradually increased; An increase in the amount of KHCO3 can make the PS particles size and monodisperse coefficients increase; With the decrease of the alcohol water ratio, PS particle size decreases, while monodisperse coefficient increases gradually.关键词：Soap-free emulsion polymerization;Nonspherical polystyrene particle;Crosslinking;Zeta potential
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发布时间：2022-09-18 - 摘要：Rotary rheometer and capillary rheometer were used to study the viscoelasticity of different syrup solution. The results showed that the zero shear viscosity of the syrup solution with different water content show exponential growth rule. There is a obvious influence of different PAM content on G’ and G" of syrup solution, and the effect on G’ is more significant. With the increase of PAM content, the relaxation time and the die swell ratio (B) increased gradually, and under the same conditions, the greater the zero shear viscosity, the more obvious the elastic effect of syrup. The viscosity of syrup solution at 20~80℃ is reversible, the influence of the temperature on viscosity of syrup solution is quiet significant, and the difference of viscosity variation can be up to 1000 times.关键词：Syrup;Viscoelasticity;Storage modulus;Loss modulus;Relaxation time;Extrudate swell
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发布时间：2022-09-18 -
A Review of Production of Polyhydroxyalkanoate by Methanotrophic Bacteria Using Methane as Feedstock
摘要：At present, most synthetic plastic materials produced from fossil carbon feedstock, which regenerated over time scales of millions of years. Petrochemical-derived plastic materials had been widely used, massive petro-plastic production consumed large amount energy resource and caused severe environmental pollution. Polyhydroxyalkanoates biosynthesized by microbe was macro polymer molecules, its physical and chemical characteristics were similar to conventional plastics such as polypropylene. Polyhydroxyalkanoates produced from renewable resource and have many advantages compared with petro-plastic, such as, it can be biodegraded in nature will not pollute environment, and the diverse structure endowed it with multiple function to feet for different use, which make polyhydroxyalkanoates extremely desirable substitutes for petro-plastic. Methane can be used as sole carbon and energy source for growth of methanotrophs. Methanotrophs can anabolism methane to accumulate polyhydroxyalkanoates in the cell at property conditions. Using methane as feedstock can substantially reducing cost for polyhydroxyalkanoates production, at the same time greatly reducing greenhouse gas emission. This article reviewed the fundamentals of strategies for reducing PHA production cost from methane and some explanation for methanotrophs, polyhydroxyalkanoates metabolic pathway, culture condition, and nutritional requirements are given.关键词：Polyhydroxyalkanoate;Methane;Methanotrophic bacteria- 2
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发布时间：2022-09-18 - 摘要：This paper focuses on the analysis of insufficience of experiments in polymer materials and engineering major students in Changzhou University. An innovative gradient experiments system mode of "2+7+2" is introduced, including experimental instruments basic training for 2 weeks, a process and synthesis comprehensive training for 7 weeks and a cognitive abilities training for 2 weeks. The difficulty and practical strength of these three parts increase. The effect of this innovative system is very good, proved by students’ behavior in the course of productive practice and graduation thesis. The engineering ability and creative consciousness of students improve, and so is the understanding of the professional knowledge.关键词：Practice ability;Experimental teaching;Engineering training;Innovative consciousness
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发布时间：2022-09-18 - 摘要："Polymer Chemistry" course is the required course for the most materials type specialy. This course aims to that the principle of the polymer synthesis and kinetics of polymerization. It includes two main contents: step polymerization and chain polymerization. The basic principle and characters of the step polymerization are described by used the polycondensation as an exemple. In allusion to the some confusable question in the polycondensation, such as the meaning for N0 and N in definition of extent of reaction and average polymerization degree, the extent of reaction in the linear polycondensation and crosslinking polycondensation, the concentration in equation
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发布时间：2022-09-18
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