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TEXTURE AND CRYSTALLINITY EVOLUTION IN ISOTACTIC POLYPROPYLENE INDUCED BY ROLLING AND THEIR INFLUENCE ON mechanical properties

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Chinese Journal of Polymer Science 2006年第4期24卷 403-411页

作者： Dierk Raabe 贾涓 Max-Planck-Institut für Eisenforschung Max-Planck-Str.1 Düsseldorf 40237Germany Department of Materials University of Science and Technology Beijing Beijing 100083 China Max-Planck-Institutfiir Eisenforschung Max-Planck-Str. 1 Dusseldorf 40237 Germany

The orientation and crystallinity evolution of isotactic polypropylene （iPP） induced by rolling were studied using wide angle X-ray scattering with an area detector. The tensile mechanical properties.of rolled isotactic polypropylene sheets were also measured in this work. The texture component method was used to analyze the rolling texture. The rolling texture consists mainly of （010）[001], （130）[001] and [001]//RD fiber components in the sample with a rolling true strain of 1.5. The results reveal that crystallinity drastically decreases during rolling. It is suggested that amorphization is a deformation mechanism which takes place as an alternative to crystallographic intralamellar slip depending on the orientation of the lamellae. Both the orientation and crystallinity affect the tensile mechanical properties.of rolled polypropylene. Crystallinity influences the elastic modulus on both directions and yield strength on transverse direction at the first stage of deformation. Orientation is the main reason for the changes of mechanical properties. especially at the latter part of deformation. The changes of both tensile strength and elongation percentage on rolling direction are larger than those on transverse direction, which results from the orientation. At last, the anisotropic mechanical properties.occur on the rolling and transverse direction： high tensile strength with low elongation percentage on rolling direction and low tensile strength with high elongation percentage on transverse direction.

关键词： Isotactic polypropylene (iPP) Texture Crystallinity Orientation mechanical properties.

THERMAL AND mechanical properties.OF POLYLACTIDE TOUGHENED WITH A BUTYL ACRYLATE-ETHYL ACRYLATE-GLYCIDYL METHACRYLATE COPOLYMER

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Chinese Journal of Polymer Science 2013年第11期31卷 1519-1527页

作者： Yan-ping Hao Huan-huan Ge Li-jing Han 张会良 Li-song Dong Shu-lin Sun Key Laboratory of Polymer Ecomaterials Chinese Academy of SciencesChangchun Institute of Applied Chemistry Changchun University of Technology

In this work, a specific polylactide （PLA） 4032D was melt-mixed with a new toughener： butyl acrylate （BA）, ethyl acrylate （EA） and glycidyl methacrylate （GMA） copolymer （BA-EA-GMA）. DMA tests showed that PLA/BA-EA-GMA blends were partially miscible. The degree of crystallinity of PLA increased while the cold crystallization temperature shifted to higher temperatures with increasing BA-EA-GMA content. The SEM micrographs showed that PLA/BA-EA-GMA blends had a good dispersion and this phenomenon was in good agreement with their higher impact strength. The result showed that the adding of BA-EA-GMA has enhanced the flexibility of PLA/BA-EA-GMA blends as compared with pure PLA. The impact strength was changed from 3.4 kJ/m2 for pure PLA to 29.6 kJ/m2 for 80/20 PLA/BA-EA-GMA blend.

关键词： Polylactide Thermal properties mechanical properties.

Influences of 2.5wt%Mn addition on the microstructure and mechanical properties.of Cu-Al-Ni shape memory alloys

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International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 192-198页

作者： Ugur Sari Department of Computer Education and Instructional Technology Faculty of EducationKinkkale University

The influences of 2.5wt%Mn addition on the microstructure and mechanical properties.of the Cu-11.9wt%Al-3.8wt%Ni shape memory alloy（SMA） were studied by means of scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,and differential scanning calorimeter（DSC）.The experimental results show that Mn addition influences considerably the austenite-martensite transformation temperatures and the kind of martensite in the Cu-Al-Ni *** martensitic transformation changes from a mixedβ1→β＇1＋γ＇1 transformation to a singleβ1→β＇1 martensite transformation together with a decrease in transformation *** addition,the observations reveal that the grain size of the Cu-Al-Ni alloy can be controlled with the addition of 2.5wt%Mn and thus its mechanical properties.can be *** Cu-Al-Ni-Mn alloy exhibits better mechanical properties.with the high ultimate compression strength and ductility of 952 MPa and 15%,*** improvements are attributed to a decrease in grain ***,the hardness decreases from Hv 230 to Hv 140 with the Mn addition.

关键词： Cu-Al-Ni shape memory alloys martensitic transformations grain size mechanical properties.

MISCIBILITY,CRYSTALLIZATION AND mechanical properties.OF PPC/PBS BLENDS

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Chinese Journal of Polymer Science 2007年第6期25卷 589-597页

作者： Hui-liang Zhang Xiao-hong Sun Qing-yong Chen Min-qiao Ren Zhi-hao Zhang Hong-fang Zhang Zhi-shen Mo State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Graduate School of Chinese Academy of Science Changchun 130022 China

In this paper, melt blends of poly（propylene carbonate）（PPC） with poly（butylene succinate）（PBS） were characterized by dynamic mechanical analysis （DMA）, differential scanning calorimetry （DSC）, tensile testing, wide-angle X-ray diffraction （WAXD）, polarized optical microscopy and thermogravimetric analysis （TGA）. The results indicated that the glass transition temperature of PPC in the 90/10 PPC/PBS blend was decreased by about 11 K comparing with that of pure PPC. The presence of 10% PBS was partially miscible with PPC. The 90/10 PPC/PBS blend had better impact and tensile strength than those of the other PPC/PBS blends. The glass transition temperature of PPC in the 80/20, 70/30, and 60/40 PPC/PBS blends was improved by about 4.9 K, 4.2 K, and 13 K comparing with that of pure PPC, respectively; which indicated the immiscibility between PPC and PBS. The DSC results indicated that the crystallization of PBS became more difficult when the PPC content increased. The matrix of PPC hindered the crystallization process of PBS. While the content of PBS was above 20%, significant crystallization-induced phase separation was observed by polarized optical microscopy. It was found from the WAXD analysis that the crystal structure of PBS did not change, and the degree of crystallinity increased with increasing PBS content in the PPC/PBS blends.

关键词： Poly(propylene carbonate) Poly(butylene succinate) Miscibility Crystallization mechanical properties.

Effect of Long Chain Branching on the Rheological Behavior,Crystallization and mechanical properties.of Polypropylene Random Copolymer

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Chinese Journal of Polymer Science 2016年第9期34卷 1158-1171页

作者： Jing Cao Na Wen 郑玉婴 College of Materials Science and Engineering Fuzhou UniversityFuzhou 350108China

Long chain branched polypropylene random copolymers （LCB-PPRs） were prepared via reactive extrusion with the addition of dicumyl peroxide （DCP） and various amounts of 1,6-hexanediol diacrylate （HDDA） into PPR. Fourier transform infrared spectrometer （FTIR） was applied to confirm the existence of branching and（ investigate the grafting degree for the modified PPRs. Melt flow index （MFI） and oscillatory shear rheological properties.including complex viscosity, storage modulus, loss tangent and the Cole-Cole plots were studied to differentiate the LCB-PPRs from linear PPR. Differential scanning calorimetry （DSC） and polarized light microscopy （PLM） were used to study the melting and crystallization behavior and the spherulite morphology, respectively. Qualitative and quantitative analyses of rheological curves demonstrated the existence of LCB. The effect of the LCB on crystalline morphology, crystallization behavior and molecular mobility, and, thereby, the mechanical properties.were studied and analyzed. Due to the entanglements between molecular chains and the nucleating effect of LCB, LCB-PPRs showed higher crystallization temperature and crystallinity, higher crystallization rate, more uniformly dispersed and much smaller crystallite compared with virgin PPR, thus giving rise to significantly improve impact strength. Moreover, the LCB-PPRs exhibited the improved yield strength. The mobility of the molecular chain segments, as demonstrated by dynamic mechanical analysis （DMA）, was improved for the modified PPRs, which also contributed to the improvement of their mechanical properties.

关键词： Polypropylene random copolymer Long chain branch Rheological properties mechanical properties.

EFFECT OF SILANE COUPLING AGENT ON THE mechanical,THERMAL properties.AND MORPHOLOGY OF TREMOLITE/PA1010 COMPOSITES

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Chinese Journal of Polymer Science 2008年第3期26卷 255-262页

作者：刘凤岐 College of Chemistry and MacDiarmid Laboratory Jilin University Changchun 130012China

Tremolite,a kind of inorganic filler,was modified with a silane coupling agentγ-methacryloxypropyl trimethoxy silane (MPS) in ethanol/ammonia *** graft of MPS on tremolite was confirmed by X-ray photoelectron spectroscopy (XPS),IR and thermogramitric analysis (TGA) *** addition,contact angle analysis showed that particle surface property was changed from hydrophilicity to hydrophobicity after the *** tremolite and pure tremolite were blended respectively with PA1010 (p...

关键词： Tremolite MPS Composite materials mechanical properties.

Effects of Sn addition on the microstructure and mechanical properties.of extruded Mg-Bi binary alloy

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Journal of Magnesium and Alloys 2022年第3期10卷 920-931页

作者： Sang-Cheol Jin Jong Un Lee Jongbin Go Hui Yu Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566South Korea Department of Materials Science and Engineering Kyoto UniversityYoshida-honmachiSakyo-kuKyoto606-8501Japan School of Materials Science and Engineering Hebei University of TechnologyTianjin 300130China

We investigated the effects of Sn addition on the microstructural characteristics and mechanical properties.of an extruded Mg-Bi binary alloy by comparing Mg-5 Bi(B5)and Mg-5 Bi-4 Sn(BT54).Both the extruded alloys exhibit a partially recrystallized grain structure with a strong extrusion fiber texture and numerous Mg3Bi2 ***,the addition of Sn significantly decreases the average grain size of the extruded alloy from 123.9 to 75.2μ*** Sn solute atoms inhibit the activity of dislocation slip,which reduces the internal strain energy accumulated in the dynamically recrystallized(DRXed)grains during ***,this reduced strain energy leads to the decrease in the DRXed grain size owing to weakened grain growth during natural *** extruded BT54 alloy exhibits higher tensile strength and ductility than the extruded B5 *** improvement in the strength by the Sn addition is attributed to the combined effects of grain refinement,Sn solute atoms,and increased dislocation *** formation of{10-11}and{10-11}-{10-12}twins during tension is suppressed by the grain refinement,thereby improving the tensile elongation considerably.

关键词： Mg±Bi alloy Extrusion Dynamic recrystallization Microstructure mechanical properties.

Combined Effects of Stretching and Nanofillers on the Crystalline Structure and mechanical properties.of Polypropylene and Single-walled Carbon Nanotube Composite Fibers

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Chinese Journal of Polymer Science 2014年第2期32卷 245-254页

作者： Yao Gao Gui-ying Zong Hong-wei Bai 傅强 College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University Zhejiang Industry & Trade Vocational College

The combined effects of stretching and single-walled carbon nanotubes （SWCNTs） on crystalline structure and mechanical properties.were systematically investigated in melt-spun polypropylene （PP） fibers prepared at two different draw ratios. The dispersion, alignment of the SWCNT bundles and interfacial crystalline structure in the composite fibers are significantly influenced by the stretching force during the melt spinning. The nanohybrid shish kebab （NHSK） superstructure where extended PP chains and aligned SWCNT bundle as hybrid shish and PP lamellae as kebab has been successfully obtained in the composite fibers prepared at the high draw ratio and the related formation mechanism is discussed based on the results of morphological observations and 2d-SAXS patterns. Large improvement in tensile strength and modulus has been realized at the high draw ratio due to the enhanced orientation and dispersion of SWCNT bundles as well as the formation of NHSK.

关键词： Stretching SWCNTs Nanohybrid shish kebab mechanical properties.

mechanical properties.OF SMC WHISKER REINFORCED HIGH DENSITY POLYETHYLENE COMPOSITES

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Chinese Journal of Polymer Science 2009年第2期27卷 267-274页

作者：傅强 College of Polymer Science and Engineering Sichuan University

A new type of SiO_2-MgO-CaO (SMC) whisker was used to modify high density polyethylene (HDPE).The melting behavior and crystallinity were investigated by differential scanning calorimetry (DSC).The dispersion of whiskers and interfacial adhesion in the prepared HDPE/SMC whisker composites were investigated by scanning electron microscopy (SEM).The mechanical properties.were evaluated by mechanical tests and dynamic mechanical analysis (DMA).DSC data indicated that the melting temperature and the crystallini...

关键词： SMC whisker Polyethylene mechanical properties.