最新刊期
卷 25 ， 期 6 ， 2012
- 摘要：Shear thickening solution based on polymer and its rheological behavior were reviewed, and the mechanism of shear thickening property analyzed. The effect of polymer concentration, molecular weight and polymer composition upon the shear thickening behavior were discussed. The applications of shear thickening solution based on polymer in various fields such as oil enhancement, the impact shock, daily chemical of engineering and so forth were also introduced.关键词：Shear thickening;Associated polymer;Intra-chain and inter-chain interaction;Application
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发布时间：2022-09-18 - 摘要：One of the research priorities and hot topics about conductive polymer composites (CPCs) is controlling the distribution of conductive filler to lower the percolation threshold and improve the combination properties. Among them, the technique for preparing CPCs with segregated conductive network, which can reduce the percolation threshold significantly, was studied extensively. In the present paper, methods for preparing CPCs with segregated conductive network were reviewed, including mechanical mixing, solution mixing, latex method, etc. The reasons for the low percolation threshold were discussed, the responses of the resistivity of these CPCs to external fields, such as temperature filed, solvent, etc., were summarized. Based on the microstructure of the CPCs, we pointed out that the enhancement of the mechanical properties is the key factor to promote the applications of these CPCs.关键词：Segregated structure;Conductive polymer composites;Percolation;Conductive filler distribution
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发布时间：2022-09-18 - 摘要：Polyphenylene sulfide (PPS) and Polytetrafluroethylene (PTFE) are corrosion-resistant resin, and also can withstand high temperature. The surface energy of PTFE is very low, and the adhesion of PPS with metal is good. So combined with the advantages of both, it’s expected to prepare a functional coating with high performance. Therefore PPS/PTFE composite coating has drawn greater attention since 1992. In this review, we firstly introduce three methods to prepare PPS/PTFE composite coatings, and then summarize the recent research work in corrosion resistance, super-hydrophobicity, scale inhibition, temperature and wear resistance of the composite coatings. The research prospects and directions of this rapidly developing field are also briefly addressed.关键词：Polyphenylene sulfide;Polytetrafluoroethylene;Corrosion-resistant;Super-hydrophobic
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发布时间：2022-09-18 - 摘要：This paper reviews the research progress of conjugated polymers containing nitrogen-nitrogen double-bond bridges, for example, azobenzene and azopyrrole compounds and their derivatives. The trans form of the azobenzene molecule has a planar structure, whereas in the cis form of azobenzene, phenyl rings are twisted around the C—N bonds. The π-conjugated structure of the azobenzene is affected by the substitution of the phenyl ring, which gives rise to the variation of the bond lengths and bond angles. The measured conductivity showed a distinct difference in the trans form and the cis forms of azobenzene. These apparent changes in conductivity were attributed to the switching of height of the molecules rather than to an internal structural modification leading to a modification of resistance. The insertion of an azo group between heterocyclic rings pronounces the complex exhibiting a broader absorption band and a lower optical band gap compared to azobenzene. Consequently, the heterocyclic azo conjugated dye is an excellent candidate to be used as the photoactive material for the bulk heterojunction photovoltaic devices. The conductivity and synthetic methods of conjugated azo polymers are described. The present research situation of electrical and photonic conductivity of azobenzene and our perspectives of the future development of conjugated azo containing polymer are also presented.关键词：Azo;Conductivity;Conjugate;Photovoltaic
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发布时间：2022-09-18 - 摘要：Vapor grown carbon nanofiber/polymer conductive composites are excellent composite materials. Compared with traditional polymer conductive composites, they show excellent electrical properties, shielding effectiveness and thermal properties. This article firstly introduces the production and properties of vapor grown carbon nanofiber, then focuses on the factors that affect the electrical properties, shielding effectiveness and thermal properties of vapor grown carbon nanofiber/polymer conductive composites. The effects of nanofibers' dispersion, distribution, concentration and aspect ratio are elaborated. Influences of processing methods such as melt mixing, in-situ polymerization and solution processing are also reviewed. This article highlights the factors affect the electrical properties of vapor grown carbon nanofiber/polymer composite, especially the effects of processing method and processing conditions.关键词：Vapor grown carbon nanofiber/polymer composites;Electrical properties;Shielding effectiveness;Thermal properties
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发布时间：2022-09-18 - 摘要：Cellulose is one of main renewable resources on plant. It has attracted significant attention because it might be feasible to be converted to valuable chemicals. So far, varies chemical and biological technologies have been investigated to tackle the hydrolysis of cellulose, and hydrolysis of cellulose in super- and subcritical water is one of new green technologies for converting cellulose to useful chemicals with high reaction speed and conversion rate. We compare the different mechanism and product distributions for hydrolysis reaction in supercritical and subcritical water. Main reaction conditions that affect the reaction rate and product distributions are summarized including reaction temperature, pressure, time, catalyst. The combined process of super- and subcritical water for cellulose hydrolysis is also introduced.关键词：Cellulose;Super-/sub-critical;Hydrolysis;Mechanism;Influence factors
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发布时间：2022-09-18 - 摘要：This paper has introduced the composition, basic properties and rheological mechanism of the shear thickening fluid (STF), factors affecting STF’s rheological mechanism and research methods studying STF’s rheological mechanism are discussed too. Besides, it has explained the preparation of silica and the polyethylene glycol (PEG) / nano-silica particles system in STF, PEG/SiO2 system’s thickening mechanism has also been commented. Based on the research on STF, this paper has studied the liquid body armor composed of STF-fabric, excellent protective properties, mechanism of bulletproof and stab-resistant (anti-spike, anti-knife) of STF-fabric have been described, besides, the mechanism of stab-resistant of STF-Kevlar has also been introduced. Next, the paper has introduced drop tower testing and quasi-static testing. And the last part of the paper presents a vision on the future research on the liquid body armor.关键词：Shear thickening fluid;SiO2;STF-fabrics;Kevlar;Liquid protective armor;Mechanism of anti-stab
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发布时间：2022-09-18 - 摘要：In this paper, the synthesis of the anionic ionomers, such as ionomers with pendent carboxyl, sulfo or phospho groups, was summarized based on the prior work. And some essential morphology models of the ionomer and their infects in application were summarized. For the structure of the ionomer, the studies of microphase separation and some breakthroughs gained by new electron microscopy technology were introduced briefly. As for the solution properties of ionomer, some relative studies of ionomer solution viscosity and the solvent functionality were discussed. And the influence of the amount and type of the ionic groups on the mechanical properties and glass transition temperature was summarized. The further research of the ionomers needed to approach was also indicated.关键词：Ionomer;Ionic clusters;Morphological models;Solution properties
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发布时间：2022-09-18 - 摘要：As one of common engineering plastics, polyoxymethylene is widely used in mechanical industry, automobile, electrical and electronic, precision instruments and other fields because of high strength and abrasion resistance, preferable adiabatic and insulation performance and excellent processability. However, the low impact toughness and poor stability limit the industrial applications of polyoxymethylene, which attracts more attention to the modification research of polyoxymethylene in recent years. Here, modification methods are reviewed and the effects of different modification technology on properties of polyoxymethylene composites are also discussed, which contain mechanical property, frictional behavior, insulation performance and stability. Finally, the development direction of industrial application of polyoxymethylene is prospected.关键词：Polyoxymethylene;Modification;Mechanical property;Friction behavior
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发布时间：2022-09-18 - 摘要：Nonlinear optical (NLO) polymers have attracted much attention in recent years. Epoxy based polymers with side hydroxyl groups have good film-forming properties and can be chemical cross-linked, which are good candidates for nonlinear optical polymers. In this paper, two kinds of iodinated aniline derivatives were synthesized by selective para-iodination between the reaction of 3-methyl aniline, 3, 5-dimethylaniline and iodine in a mixture of pyridine/dioxane under mild conditions. Three aniline derivatives with thiophene heterocycle substituent and different number of side methyl substituents were prepared by Suzuki coupling reaction between the iodinated aniline derivatives and 2-thiophenylboric acid. Three kinds of precursor epoxy based polymers were prepared by the polycondensation of diglycidyl ether of bisphenol-A and aniline derivatives prepared above. The precursor polymers were post-functionalized by tricyanovinylation reaction to prepare the final NLO polymers. The result polymers were characterized by 1H-NMR, UV-Vis, DSC, TGA and GPC methods. The methyl substitutes have much effect on the degree of electrophilic substitution reaction of the precursor polymers. For BP-TA-TC and BP-3-TA-TC, the degree of functionalization can be reached about 80%. Anyway, the degree of functionalization of BP-3, 5-TA-TC with two side methyl substitutes is less than 10%. With the increase of the number of methyl substitutes, the UV-visible maximum absorption of the final NLO polymers will decrease.关键词：Nonlinear optical (NLO);Epoxy-based polymers;Tricyanovinyl;Heteroaromatic
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发布时间：2022-09-18 - 摘要：The different molecular weight Poly(L-lactic acid) (PLLA) was investigated by differential scanning calorimetry (DSC) under different cooling rates of the crystallization process. Ozawa and Kissinger equation were applied to study the non-isothermal crystallization kinetics of PLLA. The results showed that the crystalliazation peaks shift to low direction and peak width increased with increasing of the cooling rate and the molecular weight. The crystallization activation energy are -165.8kJ/mol for the PLLA(M=2.6×104) which Ozawa exponent m closing to 3 indicated the crystallization model is heterogeneous nucleation and three-dimensional crystal growth, -82.1kJ/mol and -75.4kJ/mol for the PLLA(M=14.3×104 and 19.2×104) which Ozawa exponent m closing to 4 indicated homogeneous nucleation and three-dimensional crystal growth, respectively. The " hinge" model explains the significant difference of the crystallization activation energy of different molecular weight PLLA, and giving the relation between the molecular weight and the crystallization activation of PLLA.关键词：Polylactic acid;Non-isothermal crystallization;Crystallization kinetics;Crystallization activation energy
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发布时间：2022-09-18 - 摘要：The copolymers were synthesized with L-lactide and glycolide in the different mole ratios by ring-opening method using PEG-800 as initiator.The copolymers were characterized by Infrared Spectroscopy,1H-Nuclear Magnetic Resonance,Gel Permeation Chromatography,Contact Angle Measurement and Thermo gravimetric Analysis.The results showed that the hydrophilic of copolymers were improved when PEG-800 used as initiator,and the co-monomer GA also affect the hydrophilic of copolymers.Water absorption were tested,the results showed that with co-monomer GA increasing,water absorption was enhanced. As far as the same contain initiator PEG-800,the copolymer films with L-lactide and glycolide in the mole ratio of 3:1 had better the property of water absorption.关键词：Poly (ethylene glycol);Copolymers;Hydrophilic
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发布时间：2022-09-18 -
The Development of Pigment Dispersion Resins and Pigment Paste for Cathodic Electrophoretic Coatings
摘要：Using polyisocyanate preparation a kind of quaternary ammonium agent, again and epoxy resin were prepared response of the groups quaternary ammonium salt cationic pigment dispersion resins and pigment paste. In this paper, effects on TDI Monomer, molecular weight of epoxy resin, IO blocked TDI mole Ratio were investigated,and properties of the obtained cationic pigment dispersion resins and pigment paste were tested.The results showed that this pigment dispersion resins had excellent dispersion effect for the pigment, the pigment paste had excellent storage stability, construction stability which prepared by this pigment dispersion resins and the common pigments grinding pulp, the product had a good application prospect in the market.关键词：Polyisocyanate;Quaternary ammonium agent;Cationic pigment dispersion resins;Pigment paste- 2
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发布时间：2022-09-18 - 摘要：High performance liquid chromatography (HPLC) is widely considered as the most effective way for the synthesis and separation of optically pure enantiomers.The properties of chiral stationary phase (CSP) directly affect the chiral separation ability of a column in chiral resolution by high performance liquid chromatography.Among all the chiral stationary phases,the immobilized chiral stationary phases,which are becoming one of the most important kinds of CSPs,have the advantages of good solvent durability and enormous method flexibility.This review mainly focus on macromolecule immobilized CSPs,including polysaccharide derivatives immobilized CSPs,protein immobilized CSPs and synthetic polymer immobilized CSPs.The progress in immobilized macromolecular CSPs,especially for their loading capacity,solvent durability and resolution effects,is reviewed.关键词：High performance liquid chromatography;Immobilized chiral stationary phases;Chiral separation;Macromolecule
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发布时间：2022-09-18 - 摘要：Some suggestions were put forward in the teaching process of polymer rheology according to the teaching laws.Firstly stimulating the interest was important in leading students entering the door of rheology.The basic concepts were crucial and must be grasped in studying polymer rheology.In teaching process the emphasis must be highlighted,the difficult points must be broken,and vivid and lively samples can be introduced to interpret the abstract theories and concepts.The connection of speciality with rheology can produce new methods to understand or solve some problems.It is helpful to broden the eyesight by introducing the latest update of rheology to students.Strict assessment methods must be used to increase the learning quality of students.关键词：Polymer;Rheology;Teaching;Method
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发布时间：2022-09-18 - 摘要：This paper presents the curriculum design and teaching reform in Analysis and Testing of Polymeric Materials,which is the core course in the curriculum system of polymeric materials processing technology at Liming Vocational University.The teaching object is to achieve the realization of the transformation from students to prospective employees.After conducting a research on the enterprises concerned,we have identified the post of quality inspection as suited to the special training of the students,with the working contents being the analysis,inspection and quality assurance.And then we redesign the curriculum system based on the post and working contents,which correspond to such items as the typical method,typical product and typical commonsense respectively.The teaching of the teachers is combined with practising on the students’ side in an organic way and the teaching methods include the interactive training among students,the topic-exploring in autonomic learning,the four-step skill-training and so on.关键词：Polymeric materials;Analysis and testing;Design;Reform;Item design
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发布时间：2022-09-18 - 摘要：Properties of polymer materials are determined by their structures,and finally affect their applications.Catching this primary point and combining applications of different polymer materials,effects of chain structure (including main chain and substitute group) on glass transition temperatures are detailedly discussed from the test question in the examination of Polymer Physics.Relationship between structure and property is deeply comprehended by the students.The case teaching method makes the students’ perceptual knowledge of polymer materials and learning interests to be improved.Furthermore,the teachers’ self-education and professional skills are promoted.And then the teaching effect will be much better than the normal method.关键词：Polymer physics;Glass transition temperatures;Teaching
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发布时间：2022-09-18 - 摘要：According to the characteristics of teaching content and different teaching objects in polymer chemistry teaching,the main problems of four aspects existed in polymer chemistry teaching were carefully investigated.In order to enhance the learning initiative and enthusiasm and creativity of students on learning of polymer chemistry,the interactive and opening teaching mode was presented.The specific contents and established methods of the interactive and opening teaching mode were also introduced.Through the multi-level teaching mode of basic type,improved type and innovative type,the different needs of students in the study of polymer chemistry were satisfied.The creative thinking and innovation ability of students also were fully trained.关键词：Polymer chemistry;Teaching mode;Creative thinking;Innovation ability
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发布时间：2022-09-18
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