最新刊期
卷 30 ， 期 4 ， 2017
- 摘要：In this paper, the reutilization of discarded biomass has been reviewed from the point of discarded natural polymer. Firstly, the type of natural polymer in discarded biomass has been summarized. These discarded natural polymers have many outstanding characteristics, such as bio-renewable,abundant functional groups, biodegradable,biocompatible, non-toxic biomass. Secondly, we summarize conventional treatment methods of disused biomass, which can be used as potential materials for different applications by reuse of channels. Thirdly, the progress of reusing waste natural polymer has been reviewed, such as composite materials, adsorption materials, carrier materials,energy materials, medical polymer materials and intelligent polymer materials. In conclusion, the prospect of discarded biomass and natural polymer materials has been summarized.关键词：Discarded biomass;Waste natural polymer;Agricultural wastes;Polymer materials;Recycling resources
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发布时间：2022-09-06 - 摘要：With the diversification of market demand, functional garments are getting more and more people's attention. Self-cleaning fabric have drawn much attention due to its energy saving, water saving and eco-friendly features. Because of the excellent photocatalysis, ultraviolet shielding and anti-bacterial property, nano titanium dioxide (TiO2 ) has become the best choice to fabricate self-cleaning fabric. In this article, the photocatalytic, ultraviolet shielding and anti-bacterial mechanism of nano TiO2 were introduced. Main problems and research progress of photocatalytic self-cleaning fabric have been discussed. And the prospect of photocatalytic self-cleaning fabric was expected.关键词：Self-cleaning fabric;Nano TiO2;Photocatalysis;Modification;Loading
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发布时间：2022-09-06 - 摘要：Owing to their good corrosion performance, chemical resistance and adhesion to metallic substrates, as well as low shrinkage upon cure, epoxy resins (EPRs) have found an extensive application in anticorrosive coatings. Silicone- resin (SR) gels or chain-segments of good hydrophobicity have been introduced to cured EPR coating systems as EPR-filler coupling layers, primers of metallic substrates,dispersed or interpenetrating-polymer-network phases, copolymerizing component, etc., via hydrolysis and condensation of organosilanes and/or addition-reaction to the EPRs of linear polysiloxanes or the organosilanes, to improve the corrosion performance of the modified EPR coatings through both the hydrophobic barrier and the gel-phase or cross-link (i. e.,cross-linking chain-segment) corrosion-inhibition mechanisms; the SR volume fraction also effects both enhancements of the aging and heat resistance of the coatings. The anticorrosive performance of cured EPR coatings is increased as well upon grafting, prior to cure, of organosilane small-molecules onto the EPR backbones via alcoholysis (i. e., condensation) reaction under anhydrous catalysis between the alkoxyls of the former and the hydroxyls of the latter,due to the presence of water-digestion barrier during the service time of the coatings through hydrolysis of the unreacted alkoxy groups of the organosilane grafts. For SR-modified EPR coatings, a moderate content of ceramic (nano-oxide, clay, carbon, etc. ) fillers added may result in unique resin-ceramic two-phase morphology that produces structural hydrophobicity, inorganic-acid-salt ( chromate, phosphate,silicate, rare-earth-cerium-salt, molybdate, permanganate, etc. ) or organic-compound (8-hydroxyquinoline, chloranil, etc. ) conversion-coatings or - particles incorporated may function at resin-coating-metal interfaces as electrochemical convertive protection, and lower- electrode-potential ,active metal (Mg, Zn, etc. ) powders loaded may serve at metallic-substrate surfaces as electrochemical cathodic protection; meanwhile, each of the three types of fillers added may further increase the corrosion-inhibition effect of the resin coatings. Tailoring and optimization of the structure and morphology of EPR-SR systems, synergistically coupled by incorporation of one or more modifying fillers, has become one of the necessary approaches to the corrosion- performance maximization of SR-modified EPR coatings.关键词：Epoxy resin;Silicone;Anticorrosive coating;Barrier;Electrochemical protection
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发布时间：2022-09-06 - 摘要：Furan-based polyesters represent a family of fully or partially bio-based polymers synthesized with 2, 5- furandicarboxylic acid (FDCA) as the major monomer. Since the furan ring is rigid, the furan-based polyesters are highly comparable in structure and performance with the traditional fossil-based aromatic polyesters (e. g.,PET and PBT) which have been used in a large scale. It is thus potential to replace the traditional aromatic polyesters with the furan-based polyesters at least partially in bottles, sheets, films, fibers,etc. This paper reviews recent advances in the research on the furan-based polyesters, including the molecular structure, state of aggregation, mechanical, gas-barrier and degradation properties, as well as the relationship between them. Focus is on the outstanding gas-barrier performance of the furan- based polyesters and the relevant governing factors including the molecular structure (the asymmetric geometry and polarity of the furan ring) and the state of aggregation (such as crystallization). A brief introduction is also made on the state-of- the-art and potential applications of the furan-based polyesters in packages and textiles and an outlook is given in the research trend.关键词：Furan-based polyesters;Structure;Properties;Relationship between structure and properties
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发布时间：2022-09-06 - 摘要：In this article, dithiodiacetic acid and ethylene glycol were utilized to synthesize polyethylene dithiobisalate with p-toluenesulfonic acid as catalyst by melt polycondensation, introducing the disulfide bond into the polyester successfully. The influence of reaction temperature and reaction time on the molecular weight was investigated and the obtained products were characterized by GPC,TG and 1H-NMR.关键词：Dithiodiacetic acid;Ethylene glycol;Melt polycondensation;Disulfide bond
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发布时间：2022-09-06 - 摘要：In this article, a constitutive model based on microscopic physical mechanism was established by introducing a strain amplification factor into the statistical model of rubber elasticity, which considering the effect of dangling chains. Some parameters which relating to the polymer network, such as average molecular weight (Mc ) of chain segments with both ends attached to the network (network strands) and volume fraction (Φ) of network strands,were calculated using the molecular weight (Mc) , vinyl content (wtVi) of the polysiloxane and percent conversion (q) of vinyl groups. The primary strain amplification factor (X0),infinite strain limits of the amplification factor (XX∞) and decay exponent (z),which relating to the nanoparticles,were obtained by fitting the stress-strain data. The resulting fitting curves were in good agreement with the experimental data of both single and bimodal silicone rubber composites. The constitutive model based on microscopic physical mechanism could become the bridge connecting the macroscopic stress-strain behavior to the microscopic molecular structure parameters and our work could promisingly provide a basis for the performance improvement and optimization of silicone rubber.关键词：Statistical theory of rubber elasticity;Constitutive model;Stress-stain;Calculation and fitting
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发布时间：2022-09-06 - 摘要：This article explores hydrolysis reaction mechanism and optimal process conditions of the poly ( 6- hydroxycaproic acid) under alkalinity conditions. The results show that the greater the alkalinity, the greater the concentration of OH-,and affinity groups [OH-] direct attack on poly(6-hydroxy acid) ester group structure, make the ester bond cleavage reaction occurs, generating small molecule 6-hydroxy acid. Reaction process conditions are relatively mild. In the collector constant heating magnetic stirrer can complete depolymerization with the temperature of 100℃. Under the conditions that sodium hydroxide/poly (6-hydroxy acid) molar ratio of 4. 4,glycol/poly (6-hydroxy acid) molar ratio of 6. 5,water consumption of 100g, catalyst of 0. 1g, reaction time of 2h, the reaction temperature of 100℃, 6- hydroxycaproic acid yield up to 84. 07%.The smaller the alkalinity, the smaller the concentration of OH-,and in the early stage of the reaction,the affinity group [-OCH2CH2OH] was dominant,and the probability of occurrence of alcoholysis reaction is great,and alcoholysis reaction and alkaline reaction are mutually promoting in the entire reaction system. Reaction process conditions are relatively harsh, must be fully depolymerization at 180℃ sealed autoclave. Under the conditions that sodium bicarbonate/ poly(6-hydroxy acid) molar ratio of 1. 1,glycol/poly( 6-hydroxy acid) molar ratio of 3, water consumption of 100g, catalyst of 0.1g, reaction time of 1h, the reaction temperature of 180℃~190℃ , 6- hydroxycaproic acid yield up to 90.38%. In the whole reaction system, ethylene glycol is used as a solvent.关键词：Poly(6-hydroxycaproic acid);Hydrolysis reaction;Alkaline condition
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发布时间：2022-09-06 - 摘要：Under the alkaline condition of sodium hydroxide, the polyhydroxylated polybutadiene (PHPB) was synthesized by hydroxyl terminated polybutadiene ( HTPB) and epichlorohydrin (ECH). Tetrabutyl ammonium bromide (TBAB) as the catalyst in this reaction. The structure and thermal stability of raw material, intermediate products and product were analyzed by Infrared spectroscopy (IR),thermogravimetry (TG) and nuclear magnetic resonance (1H- MNR). The effect of reaction temperature, reaction time, raw material ratio,catalyst dosage and dosage of sodium hydroxide on the on the PHPB synthesis were investigated in detail by the hydroxyl value, viscosity and yield of the product. The result showed that the optimum synthesis conditions were as follows : reaction temperature was 55℃, reaction time was 1. 5h, n(HTPB) :n(ECH) : n(NaOH) :n(TBAB) = 1:2. 9:3:0. 03.关键词：Polyhydroxylated polybutadiene;Hydroxyl terminated polybutadiene;Epichlorohydrin
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发布时间：2022-09-06 - 摘要：In order to understand the general laws of polymerization, this paper firstly compared different polymerization methods and illustrated the multi-step reaction characteristics. Then the influences of the accompanying reactions or side reactions, polymerization thermodynamics, polymer properties, solvent and polymer molecular morphology on polymerization were mainly discussed. It is helpful to understand the characteristics and influencing factors of polymerization by revealing its particularity and complexity.关键词：Teaching;Polymerization reaction;Characteristics;Influencing factors
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发布时间：2022-09-06 - 摘要：To master polymerization process and control is a basic skill for students majored in polymer engineering field. Based on visualizing and interactive method, teaching mode innovation of polymer polymerization technology is explored in our college, to train the student's ability of independent thinking and engineering practice,to improve the teaching quality. With the "Internet + teaching" developing, so many teaching forms such as microlecture, flipped classroom, and MOOC have been provided for educators learn, and role in teaching process between teachers and students are reversed. With the aim of teaching innovation, the paper investigate some teaching minds and practice for the educational reform in Internet + "polymer polymerization technology",combining with the original teaching methods and evaluation model. The investigation is a reference to optimizing the teaching method and improve the teaching quality for peers.关键词：Polymer polymerization technology;Internet+;Interactive teaching;Flipped classroom;Exploration
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发布时间：2022-09-06
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