最新刊期
卷 32 ， 期 6 ， 2019
- 摘要：Incorporation of a liquid-crystalline polyester (LCP) into a poly(bisphenol-A carbonate) (PC) matrix is able to significantly improve the processability of their composites,and meantime form the LCP microfibrils of high aspect ratio, modulus and strength in situ within them. Nevertheless, owing to the poor PC-LCP compatibility, people have met difficulties greatly enhancing the mechanical properties of the PC/LCP composites. This work has reviewed the advances in the study of LCP-reinforced PC composites,where,particularly, the compatibilization technologies as well as the reinforcement methods are explicated of the PC/LCP composite system, and the effects are discussed of its preparation process conditions, such as temperature, shear rate, viscosity ratio,draw ratio,reprocessing, etc.,on LCP microfibril formation and mechanical properties. Promisingly, it is becoming one of the potential development directions to prepare(ionized PC)/LCP composites of significant reinforcement through the strengthening of PC matrix from its ionic cross-linking and their interfacial compatibilization from strong ion-dipole interactions.关键词：Poly(bisphenol-A carbonate);Liquid-crystalline polyester;Composite;Compatibility;Reinforcement
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发布时间：2022-09-02 - 摘要：According to the estimates of the Chinese Academy of Engineering, the loss caused by corrosion in China is more than trillions of RMB every year Chinese Academy of Engineering. Corrosion damage is a common problem all over the world. Polyurethane coating plays an important role in the coating industry due to its excellent properties and is widely used in corrosion protection of materials. In order to further improve the corrosion resistance of the products, the researchers used different modification methods to prepare polyurethane anti-corrosive coatings with different functions. This article generalizes and introduces modification methods of polyurethane anti-corrosive coatings, which include Organic resin modification, nano material modification, corrosion inhibitor modification and microcapsule self-repairing modification. Meanwhile, the research progress of polyurethane coating in the field of anti-corrosion is introduced, and the future research direction and development trend are prospected.关键词：Polyurethane;Coating;Corrosion protection;Modification
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发布时间：2022-09-02 - 摘要：Hydrosilylation catalyzed by transition metal salts (Pt, Rh, Ir, Ru, Fe,etc.) and their complexes is an important reaction in industry. This reaction process is mainly the addition of Si—H bond in silicon compounds to unsaturated bond in organic compounds under certain conditions. Platinum complexes are the most popular catalysts for hydrosilylation, due to the excellent catalytic activity, high conversion and good stereoselectivity. In this paper, the catalytic mechanisms of homogeneous platinum catalysts and heterogeneous platinum catalysts for hydrosilylation are illustrated. The spatial structure, catalytic activity, stability, stereoselectivity and recyclability of thermally-driven platinum catalysts for hydrosilylation over the ten years are reviewed. How to improve and control the stereoselectivity and regenerability of platinum catalysts are also discussed. In addition to thermally-activated platinum catalysts, platinum catalysts which are activated by light or mechanical fore are also summarized. Finally,the further development trend of platinum catalysts of hydrosilylation is prospected.关键词：Hydrosilylation;Platinum catalyst;Thermal catalysis;Photocatalysis;Mechanic catalys
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发布时间：2022-09-02 - 摘要：Non-isocyanate polyurethane (NIPU) monomer was firstly prepared by ring-opening of propylene carbonate(PC) and ethylene diamine (EDA), then NIPUA monomer containing urethane bond (—NHCOO—)and C=C double bond was synthesised by esterification between acryloyl chloride (AC) and end-hydroxyl of NIPU. The synthesized NIPUA monomer was polyadded and cured with butyl acrylate(BA),acrylic acid(AA) by the effect of benzoyl peroxide(BPO) and N,N-dimethylaniline(DMP) to obtain the new urethane acrylate adhensive. Finally,the synthesis and cure process was optimized and it was found that the optimal conditions were BPO and DMP content was 7.5% (wt),NIPUA content was 40% (wt), BA content was 35 % (wt), AA content was 10% (wt), curing temperature was 60℃, curing time was 48 h. Under the optimized condition, the adhesive tensile strength can up to 1.56 MPa and gel fraction can reach 69.43%. Furthermore,the experiments of water absorption showed that the bibulous rate was the highest (about 19.25%) when acetoacetoxyethyl methacrylate (AAEM) was not added, while it was the lowest (about 9%) when AAEM content was 5%(wt).关键词：Non-isocyanate;Polyurethane acrylic;Adhesive;Tensile strength;Gel fraction;Water absorption
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发布时间：2022-09-02 - 摘要：Using plasma method to treat the polydimethylsiloxane (PDMS) substrates and glass's surface, exploring the optimal process parameter combination of polydimethylsiloxane (PDMS) matrix and glass bonding, the relationship between bonding effect and bonding time,and the relationship between PDMS substrate placement time and bonding area. The test results showed that the influencing factors were oxygen flow > cleaning time > radio frequency from primary to secondary. The optimal parameter combination of test scheme was 250W, 2L/min, 1min; the most suitable bonding time was 12h, during this time the longer the bonding time,the better the bonding effect; the longer the PDMS substrate was placed, the worse the bonding effect was. To ensure the bonding quality, bonding test was usually performed within 10 minutes after the surface treatment.关键词：Polydimethylsiloxane;Plasma method;Orthogonal test;Bonding area;Bonding effect
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发布时间：2022-09-02 - 摘要：In this paper, dipalmitoylphosphatidylcholine (DPPC),hydrogenated soybean phospholipid (HSPC) and distearylethanolamine-polyethylene glycol 2000 (DSPE-PEG2000) were used as raw material, use of reverse phase evaporation method to prepare a new type of intelligent drug controlled release polymer material which encapsulates the active ingredient berberine of traditional Chinese medicine coptis (berberine thermosensitive liposomes). The morphology and property of the product were characterized by Transmission Electron Microscope (TEM),UV spectrophotometer(UV),Zeta potential and Phase Analysis Light Scattering (ZetaPALS) and Differential Scanning Calorimeter (DSC). The release rule in vitro of the product was studied as well. The experimental results showed that the thermosensitive liposomes with a particle of berberine were synthesized successfully. Confirmed that the size of the product is 311 nm, the phase transition temperature is 317. 35 K,the effect that the temperature-sensitive liposome encapsulates the berberine is good, the encapsulation efficiency was 74%, in vitro release kinetics model of the berberine thermosensitive liposomes accorded with Ritger-Peppas equation.关键词：Controlled drug release;Polymer material;Liposome;Thermosensitive;Drug release in vitro
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发布时间：2022-09-02 - 摘要：Poly(L-lactide acid)/polycaprolactone (PLLA/PCL) composites nanofibers three-dimensional porous scaffold was prepared by low-temperature quenching, extraction, washing and drying from tetrahydrofuran solution without the assistance of other additives. The effects of PLLA/PCL ratio,concentration and quenching temperature etc. on the morphology of fibrous scaffold was investigated by SEM. The influence of addition of PVP in mechanical property and bioactivity were also investigated through compression strength,impact strength, porosity,specific surface areas and in vitro bioactivity test. The results show that fibrous scaffold was produced by crystallization of PLLA. The addition of PCL impeded the crystallization of PLLA and increased mechanical strength of fibrous scaffold. The optimum test conditions as followed: PLLA/PCL=8: 2, concentration 7 % (wt), and quenching temperature —10℃,the uniform composites nanofibers there-dimensional porous scaffold with diameter of 150~500 nm was obtained. The compression strength and impact strength of fibrous scaffold were 17. 3 MPa and 5. 6 kJ/m2,respectively. The porosity and specific surface areas of fibrous scaffold were 96.3% and 10.84 m2/g respectively. High porosity and specific surface areas will offer good condition of cell adhesion, cell differentiation, cell prolifer and nutrients transport.关键词：Poly(L-lactide acid);Polycaprolactone;Nanofibers;Scaffold;Porous
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发布时间：2022-09-02 - 摘要："High molecular weight" is the most important characteristic of polymers compared with small molecules. It leads to various unconventional rheological phenomena such as "high viscosity" and "shear thinning". Discussions on "high viscosity" and "shear thinning" of polymer liquids were made on the causes,the guiding opinions on material production, the links with daily life and the influences of temperature and concentration. The author introduced the accumulation of contents and examples in the teaching process to deepen the understanding of the students on polymer rheology and increase the students' interest in learning.关键词：Polymer;Viscosity;Shear thinning
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发布时间：2022-09-02 - 摘要：Nowadays, there is an endless stream of research on new polymer materials. The introduction of new research results into the undergraduate teaching will greatly enhance the students' interest in polymer science and materials. This will also be beneficial for the long-term development of polymer materials. The preparation of high strength hydrogel is a hotting research topic in the field of polymer materials in recent years and there are many new interesting research reported. Focusing on how to enhance the students' comprehension of polymer chemistry and polymer physics curriculums,and how to improve the students' operational ability,we designed a simple and practical route for the preparation and characterization of high strength hydrogel for undergraduate students. This article introduces our new comprehensive experiment project of "Preparation and characterization of high strength hydrogel" facing to the undergraduate students and its teaching effect analysis.关键词：Researching experiment;Experimental teaching and reform;High strength hydrogel;Research ability;Teaching effect analysis
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发布时间：2022-09-02 - 摘要：The purpose of engineering education is to train students to be responsible engineers. For engineering graduates, the ability to solve engineering problems is basic requirement. For this reason,we have practiced teaching reform of polymer materials specialty experiments. The core goal of this teaching reform is to cultivate student's ability to solve engineering problems. In this reform, the course contents were divided into three parts including preparation of polymer materials,moulding processing, structure and performance testing. The students' engineering ability was cultivated by solving the defect of moulding process;The students' team working ability and communication skills was trained through experimental division of labor and data sharing. The reform make the course form characteristics of modularization, serialization,training and standardization, and achieved good teaching results.关键词：Engineering problems;Polymer specialty experiments;Teaching reform
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发布时间：2022-09-02
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