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Chinese Journal of Polymer Science 2013年第11期31卷 1563-1578页

作者： Jin-hua Leng Heng Liu 何波兵 Bin Yang Xian Chen Qing-quan Qin Polymer Physics and Chemistry College of ChemistrySichuan University Chengdu Product Quality Supervision and Inspection Institute Kaixian Chenjia Middle School

Although addition of β-nucleating agent directly into homo-polypropylene （PPH） is a useful method to improve ,β-crystal content and toughen PPH, polypropylene random copolymer （PPR） makes this method powerless due to its random structure and low crystallinity. In this study, the β-nucleated PPR with high β-crystal content was prepared by a novel high effective β-nucleating system which consists of β-nucleation agent （TMB-5） and modified zeolite 13X （M13X）. It was found that M13X and TMB-5 had a synergistic influence on improving β-crystal content and toughening PPR. The content of β-crystal in PPR/M13X/TMB-5 was significantly larger than the sum of that in PPR/M13X and PPR/TMB-5. Besides, fracture behavior, phase morphology and relaxation of matrix chain segments were also investigated. The results showed that M13X and TMB-5 improved the mobility of amorphous chain segments at low temperature and contributed to much energy dissipation. This work provides a powerful method to modify PPR.

关键词： Polypropylene random copolymer Zeolite fl-nucleating agent Crystallization toughness.

High toughness.alumina ceramics with elongated grains developed from seeds

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Science China(Technological Sciences) 2003年第5期46卷 527-536页

作者：谢志鹏高立春李文超徐利华王习东 Department of Materials Science and Engineering Tsinghua University Beijing 100084 China University of Science and Technology Beijing Beijing 100083 China

In the present paper, the influence of α-AI_2Ol_3 seeds and sinteringmethods on elongated grain growth and fracture toughness.is investigated. The preparation of aluminaceramics started with commercial aluminum hydroxide. Abrasives were introduced to the startingmaterials by wet-grinding of high-purity alumina milling balls. Abrasives, playing the role ofseeds, lowered the transformation temperature of aluminum hydroxide to alumina. Microstructures withelongated grains were developed by hot-pressing for the above calcined powders containingα-AI_2O_3 seeds, and alumina grain shapes changed with the amount of seeds introduced. However,only equiaxed grains were observed for the samples pressureless sintered. Fracture toughness.of thealumina ceramics was dramatically improved by elongated grains. For the sample hot-pressed at 1600℃for 2 h under 40 MPa pressure, fracture toughness.reached 7.1 MPa·m^(1/2), which is much higherthan that of normal alumina ceramics without elongated grains. In addition, high flexural strengthof 630 MPa for the hot-pressed samples was also obtained.

关键词： alumina elongated grains, α-Al2O3 seeds, aluminum hydroxide, fracture toughness.

Effect of Hyperbranched Polyester on Modification of Epoxy Resins Cured with Anhydride

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Chinese Chemical Letters 2006年第1期17卷 125-128页

作者： Xiu Xia WANG Zhi Gang JIANG Yi Feng ZHANG Depaxtment of Polymer Science and Engineering Zhejiang University Hangzhou 310027

The synthesis and characterization of hyperbranched polyester （HBP） with different molecular weight are studied. The effect of HBP on the modification of epoxy resins cured with anhydride is mainly discussed. The characteristics of HBP and the morphologies of cured system are determined by nuclear magnetic resonance spectroscopy （NMR）, gel permeation chromatography （GPC） and scanning electron microscope （SEM）. The impact strength of cured system is detected and Fourier transform infrared （FTIR） measurements were used to pursue the curing process. The investigation shows that HBP can improve the toughness.by forming copolymer networks between epoxy resins, HBP and anhydride. Moreover, when the molecular weight of HBP is 1342g/mol the toughening effect is the best, and the changes of toughness.are small with the increase of molecular weight of HBP to 3500 g/mol.

关键词： Hyperbranched polyester epoxy resins modification toughness.

THE VALENCE ELECTRON STRUCTURES OF MARTENSITE IN LOW ALLOY ULTRAHIGH-STRENGTH STEELS AND THEIR INFLUENCE ON STRENGTH AND toughness

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Chinese Science Bulletin 1991年第5期36卷 366-371页

作者：刘志林戴天时屈庸博杨双良张振宇 Division of Applied Physics Jilin University of Technology Changchun 130025 PRC

Ⅰ. THE VALENCE ELECTRON STRUCTURES OF MARTENSITE IN LOW ALLOY ULTRAHIGH-STRENGTH STEELS AND THE SEGREGATION OF C-ME IN MARTENSITEThe valence electron structures ofmartensite in 30CrMnSiNi2A and Gc-4 steels can be established based on Refs. [1—3]. To be brief, only σ, nA and ncD are listed in Table 1, which are the values of electron structures of martensite in 30CrMnSi2A and Gc-4 steels.

关键词： low alloy ultra-high-strength steel martensite valence electron structure strength and toughness.

Innovative Application of Scrap-Tire Steel Cords in Concrete Mixes

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Journal of Environmental Science and Engineering(B) 2012年第4期1卷 441-446页

作者： Ahmed N. Bdour Civil Engineering Department College of Engineering University of Tabuk Tabuk 71491 KSA

Many researchers have investigated the use of recycled tire products in several traditional civil engineering materials. This research is exploring the use of steel cords, a by-product of the tire recycling process, in concrete mixes. Different concrete specimens were fabricated and tested in uniaxial compression and splitting tensile strength. The steel cords were substituted into the concrete mix in volumetric percentages of various ratios. Results show that mechanical properties of concrete made with steel cords are improved compared with concrete mix made with the traditional scrap-tires recycled material. Also, results show that even though the compressive strength is reduced when using steel cords, this reduction is minimal. When 2% of steel cords are used there is 18% increase in ductility. Moreover, splitting tensile tests show that concrete mixtures with any steel cords content have much greater toughness.than control mixture. This mechanical property mix indicates an excellent potential application of modified concrete mix in structures that absorb large amount of energy.

关键词： Steel cords scrap-tires splitting tension strength toughness.

Interlaminar Fracture toughness.and Low-Velocity Impact Resistance of Woven Glass Epoxy Composite Laminates of EP3 Grade

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Journal of Minerals and Materials Characterization and Engineering 2012年第3期11卷 321-333页

作者： N. Rajesh Mathivanan J. Jerald Department of Mechanical Engg. P. E. S. Institute of Technology Bangalore - 85 India Dept. of Production Engg. National Institute of Technology Tiruchirappalli - 15 India

This work presents the delamination resistance of woven glass fibre reinforced polymers (GFRP) and its influence on GFRP’s resistance to point impact. Two different types of laminates were fabricated by hand lay-up technique;(i) woven glass fibre epoxy matrix laminates and (ii) woven glass fibre epoxy matrix laminates with 3% graphite particulate fillers. End Notch Flexure (ENF) test was adopted for the measurement of delamination resistance. The two GFRPs laminates show similar mode II delamination resistance. At impact velocities between 2.215 and 4.429 m/sec, the GFRP developed a smaller damage size than the graphite-based GFRP laminates, indicating higher impact toughness. Difference of the impact resistance between the two GFRPs is mainly on the impact damage size developed. The total energy absorbed during the impact remains the same, which is independent of mode II delamination resistance of the GFRP. The history of relevant dynamic and energetic quantities, both to synthesize the dependency of the energy parameters and force threshold values on the impact velocity are discussed.

关键词： Polymer matrix composite Fibre Laminates Impact toughness.

Development of the High toughness.Spirally Submerged Arc Welded Pipe Line

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China Oil & Gas 1995年第4期2卷 35-37页

作者： Li Genquan(Baoji Welded Pipe Research Institute, CNPC) Baoji Welded Pipe Research Institute CNPC

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关键词： Pipe line. High. toughness. Submerged arc welding

EXPERIMENT STUDY ON toughness.OF FIBER REINFORCED HIGH PERFORMANCE LIGHTWEIGHT AGGREGATE CONCRETE

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EXPERIMENT STUDY ON TOUGHNESS OF FIBER REINFORCED HIGH PERFO...