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Influence ofβ-nucleating Compound Agents on the Mechanical Properties and Crystallization Behavior of Polypropylene Random Copolymer 被引量:2
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作者 谷亚新 LIU Yunxue +3 位作者 FAN Zhaorong GUI Jianfeng 刘鹏 WANG Hongmei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第1期237-243,共7页
A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifie... A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifier(TPE/WBG-2/CaCO_(3)).The effects of differentβ-nucleating agents and ternary compound modifier on the mechanical properties and crystallization behavior of PPR were analyzed.The results show that,compared with pure PPR materials,both WBG-2 and TMB-5 could significantly improve the impact strength of PPR.The crystallization temperature of PPR increased with the addition ofβ-nucleating agent.The modified PPR prepared with ternary compound modifier showed the most excellent comprehensive properties. 展开更多
关键词 polypropylene random copolymer β-nucleating agent impact strength crystallization behavior
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Effect of fractures on mechanical behavior of sand powder 3D printing rock analogue under triaxial compression
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作者 LI Pi-mao JIANG Li-shuai +5 位作者 WEN Zhi-jie WU Chao-lei YANG Yi-ming PENG Xiao-han WU Quan-sen WU Quan-lin 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2703-2716,共14页
In practical engineering applications,rock mass are often found to be subjected to a triaxial stress state.Concurrently,defects like joints and fractures have a notable impact on the mechanical behavior of rock mass.S... In practical engineering applications,rock mass are often found to be subjected to a triaxial stress state.Concurrently,defects like joints and fractures have a notable impact on the mechanical behavior of rock mass.Such defects are identified as crucial contributors to the failure and instability of the surrounding rock,subsequently impacting the engineering stability.The study aimed to investigate the impact of fracture geometry and confining pressure on the deformation,failure characteristics,and strength of specimens using sand powder 3D printing technology and conventional triaxial compression tests.The results indicate that the number of fractures present considerably influences the peak strength,axial peak strain and elastic modulus of the specimens.Confining pressure is an important factor affecting the failure pattern of the specimen,under which the specimen is more prone to shear failure,but the initiation,expansion and penetration processes of secondary cracks in different fracture specimens are different.This study confirmed the feasibility of using sand powder 3D printing specimens as soft rock analogs for triaxial compression research.The insights from this research are deemed essential for a deeper understanding of the mechanical behavior of fractured surrounding rocks when under triaxial stress state. 展开更多
关键词 sand powder 3D printing triaxial compression confining pressure fracture geometry mechanical behavior
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INFLUENCE OF SAMPLE THICKNESS ON ISOTHERMAL CRYSTALLIZATION KINETICS OF POLYMERS IN A CONFINED VOLUME 被引量:5
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作者 Hui Sun Zhi-ying Zhang +1 位作者 Shi-zhen Wu Bin Yu and Chang-fa Xiao School of Materials Science and Chemical Engineering,Tianjin Polytechnic University,Tianjin 300160,China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2005年第6期657-663,共7页
Isothermal crystallization process of polymers in a confined volume was simulated in the case of instantaneous nucleation by use of the Monte Carlo method.The influence of sample thickness on some kinetic parameters o... Isothermal crystallization process of polymers in a confined volume was simulated in the case of instantaneous nucleation by use of the Monte Carlo method.The influence of sample thickness on some kinetic parameters of crystallization was quantitatively evaluated.It was found that there was a critical thickness value.Influence of thickness on the crystallization behavior was only found for samples of thickness near and less than the critical value.For thick samples the Avrami plot showed straight lines with a turning point at the late stage of crystallization due to the secondary crystallization.When the thickness was near or less than the critical value a primary turning point appeared in the Avrami plot at the very beginning of the crystallization process.A model was proposed to explain the mechanism of this phenomenon.According to this model the critical thickness value is related to the nucleation density or the average distance between adjacent nuclei,and the primary turning point is an indication of a transformation of crystal growth geometry from a three-dimensional mode to a two-dimensional one.Analysis of experimental results of PEO isothermally crystallized at 53.5℃ was consistent with the proposed model. 展开更多
关键词 Avrami equation Isothermal crystallization confined volume Sample thickness
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Effect of yttrium on thermal stability and crystallization behavior of Nd_(60)Fe_(20)Al_(10)Ni_(10) amorphous alloys 被引量:3
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作者 张莎莎 田学雷 孔凡利 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第5期735-740,共6页
The effect of yttrium on the thermal stability and crystallization behavior of Nd-Fe-Al-Ni amorphous alloys was investigated using X-ray diffraction (XRD), differential scanning calorimeter (DSC), and transmission... The effect of yttrium on the thermal stability and crystallization behavior of Nd-Fe-Al-Ni amorphous alloys was investigated using X-ray diffraction (XRD), differential scanning calorimeter (DSC), and transmission electron microscopy (TEM).The results indicated that the as-cast Nd60Fe20Al10Ni10-xYx(X=-0, 2) amorphous alloys were fabricated with some quenched-in crystals, which could be restrained by Y. With the effect of yttrium, both the crystallization temperature and exothermic peak shifted to higher temperatures, illustrating that the thermal stability could be improved. The addition of Y changed the crystallization process and final crystallization results. Moreover, the crystallites in the amorphous matrix became more homogeneous and smaller. Meanwhile, Y was useful for the passivation of oxygen in chemistry and restrained the negative effect of oxygen. The activation energies of the start of crystallization and peaking were 1.21 and 1.16 eV, respectively, according to the Kissinger equation. 展开更多
关键词 Nd-based amorphous alloy quenched-in crystals thermal stability crystallization behavior activation energy rare earths
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Miscibility, Crystallization, and Rheological Behavior of Solution Casting Poly(3-hydroxybutyrate)/poly(ethylene succinate) Blends Probed by Differential Scanning Calorimetry, Rheology, and Optical Microscope Techniques
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作者 孙伟华 乔晓平 +1 位作者 曹启坤 刘结平 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第1期107-112,I0002,共7页
The miscibility and crystallization of solution casting biodegradable poly(3-hydroxybuty- rate)/poly(ethylene succinate) (PHB/PES) blends was investigated by differential scanning calorimetry, rheology, and opti... The miscibility and crystallization of solution casting biodegradable poly(3-hydroxybuty- rate)/poly(ethylene succinate) (PHB/PES) blends was investigated by differential scanning calorimetry, rheology, and optical microscopy. The blends showed two glass transition temperatures and a depression of melting temperature of PHB with compositions in phase diagram, which indicated that the blend was partially miscible. The morphology observation supported this result. It was found that the PHB and PES can crystallize simultaneously or upon stepwise depending on the crystallization temperatures and compositions. The spherulite growth rate of PHB increased with increasing of PES content. The influence of compositions on the spherulitic growth rate for the partially miscible polymer blends was discussed. 展开更多
关键词 MISCIBILITY Poly(3-hydroxybutyrate)/poly(ethylene succinate) blend Phase behavior crystallization
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Dynamic mechanical behavior of a Zr-based bulk metallic glass during glass transition and crystallization 被引量:2
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作者 CHAO Qi WANG Qing DONG Yuanda 《Rare Metals》 SCIE EI CAS CSCD 2009年第1期72-76,共5页
The dynamic mechanical behaviors of the Zr41Ti14Cu12.5Ni8Be22.5Fe2 bulk metallic glass (BMG) during continuous heating at a constant rate were investigated. The glass transition and crystallization of the Zr-based B... The dynamic mechanical behaviors of the Zr41Ti14Cu12.5Ni8Be22.5Fe2 bulk metallic glass (BMG) during continuous heating at a constant rate were investigated. The glass transition and crystallization of the Zr-based BMG were thus characterized by the measurements of storage modulus E′ and internal friction Q^-1. It was found that the variations of these dynamic mechanical quantities with temperature were interre-lated and were well in agreement with the DSC trace obtained at the same heating rate. The origin of the first peak in the internal friction curve was closely related to the dynamic glass transition and subsequent primary crystallization. Moreover, it can be well described by a physical model, which can characterize atomic mobility and mechanical response of disordered condense materials. In comparison with the DSC trace, the relative position of the first internal friction peak of the BMG was found to be dependent on its thermal stability against crys-tallization. 展开更多
关键词 metallic glass dynamic mechanical behavior internal friction glass transition crystallization
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FRACTAL BEHAVIOR OF DEVELOPMENT OF PHASE SEPARATION AND CRYSTALLIZATION IN BLENDS OF NYLON-6 WITH SODIUM SALT OF ETHYLENE /METHACRYLIC ACID COPOLYMER
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作者 韩蕴萍 盛京 李著萍 《Transactions of Tianjin University》 EI CAS 1999年第2期93-97,共5页
Phase separation was studied by the optical microscopy in blends of nylon 6 (PA6) with sodium salt of ethylene/methacrylic acid copolymer (PEMA).The image collecting technology was used to keep track of the developme... Phase separation was studied by the optical microscopy in blends of nylon 6 (PA6) with sodium salt of ethylene/methacrylic acid copolymer (PEMA).The image collecting technology was used to keep track of the development of blends at a certain temperature.The fractal dimension of phase separation was calculated by the image solving technology according to the fractal theory and the self similarity behavior of the process was proved.The relationship of the fractal behavior with composition and experimental temperature was discussed.The fractal behavior of the crystallization development of the crystal phase of PA6 in blends was also discussed and the fractal behavior calculated. 展开更多
关键词 phase separation of nylon 6 blends fractal behavior of phase separation fractal behavior of development of crystallization
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Phase behaviors in a binary mixture of diblock copolymers confined between two parallel walls 被引量:1
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作者 潘俊星 张进军 +2 位作者 王宝凤 武海顺 孙敏娜 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期372-380,共9页
The phase behaviors in a binary mixture of diblock copolymers confined between two parallel walls are investigated by using a cell dynamics simulation of the time-dependent Ginzburg-Landau theory.The morphological dep... The phase behaviors in a binary mixture of diblock copolymers confined between two parallel walls are investigated by using a cell dynamics simulation of the time-dependent Ginzburg-Landau theory.The morphological dependence of the wall-block interaction and the distance between walls(confinement degree) has been systematically studied,and the effect of repulsive interactions between different monomers is also discussed.It is interesting that multiple novel morphological transitions are observed by changing these factors,and various multilayered sandwich structures are formed in the mixture.Furthermore,the parametric dependence and physical reasons for the microdomain growth and orientational order transitions are discussed.From the simulation,we find that much richer morphologies can form in a binary mixture of diblock copolymers than those in a pure diblock copolymer.Our results provide an insight into the phase behaviors under parallel wall confinement and may provide guidance for experimentalists.This model system can also give a simple way to realize orientational order transition in soft materials through confinement. 展开更多
关键词 parallel walls confinement phase behavior binary mixture diblock copolymer
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Influence of Carbon Nanofiber Addition on Mechanical Properties and Crystallization Behavior of Polypropylene 被引量:1
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作者 Xin TONG Yong CHEN Huiming CHENG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2005年第5期686-690,共5页
Carbon nanofiber (CNF)-reinforced polypropylene (CNF/PP) composites with different CNF contents were prepared by melt mixing, and the mechanical properties and crystallization behavior of the CNF/PP composites obt... Carbon nanofiber (CNF)-reinforced polypropylene (CNF/PP) composites with different CNF contents were prepared by melt mixing, and the mechanical properties and crystallization behavior of the CNF/PP composites obtained were investigated. It was found that the tensile modulus of the composites was increased with the addition of CNFs, but their elongation at break and fracture strain energy were decreased, while the tensile strength of the composites was firstly increased and then decreased due to the agglomeration of CNFs at higher loading. Nonisothermal crystallization analysis showed that the CNFs played a role as nucleating agent in PP matrix, which led to increment in the crystallization rate and the degree of crystallinity of PP. Moreover, X-ray diffraction studies showed that the CNFs incorporated in the PP matrix favored the growth of (040)-oriented PP crystals. With the increase in the CNF content, the nucleating and orientation roles of the CNFs were obviously enhanced. 展开更多
关键词 Carbon nanofibers COMPOSITES Mechanical properties crystallization behavior
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Crystallization behavior of Fe_(78)Si_(13)B_9 metallic glass under high magnetic field 被引量:1
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作者 Yuanfei Yu Baozhu Liu Min Qi 《Journal of University of Science and Technology Beijing》 CSCD 2008年第5期600-604,共5页
The effects of high magnetic field on the crystallization behavior of the Fe78Si13B9 metallic glass ribbon were studied. The samples were isothermal annealed for 30 min under high magnetic field and no field,respectiv... The effects of high magnetic field on the crystallization behavior of the Fe78Si13B9 metallic glass ribbon were studied. The samples were isothermal annealed for 30 min under high magnetic field and no field,respectively. Microstructure transformation during crystallization was identified by X-ray diffraction and transmission electron microscopy. It was found that the crystallizations of Fe78Si13B9 metallic glass processed under different conditions were that the precipitation of dendrite α-Fe(Si) and spherulite (Fe,Si)3B phases forms amorphous matrix and then the metastable (Fe,Si)3B phase transforms into the stable Fe2B phase. The grain size of the crystals is smaller and more homogeneous for the isothermal annealed samples under high magnetic field in comparison with that under no field indicating that the crystallization behavior of Fe78Si13B9 metallic glass is suppressed by high magnetic field. 展开更多
关键词 metallic glass high magnetic field isothermal annealing crystallization behavior
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Effect of Rare Earth on the Crystallization Behavior of Li_2O-Al_2O_3-SiO_2 Glass-ceramic 被引量:1
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作者 吴松全 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2009年第S1期123-127,共5页
X-ray powder diffraction and Fourier transform infrared spectroscopy were applied for characterization of Li2O-Al2O3-SiO2 glass-ceramic powders doped with Eu2O3,Gd2O3 and Er2O3,respectively,in the conditions of differ... X-ray powder diffraction and Fourier transform infrared spectroscopy were applied for characterization of Li2O-Al2O3-SiO2 glass-ceramic powders doped with Eu2O3,Gd2O3 and Er2O3,respectively,in the conditions of different heat-treatment temperatures and with various amounts.The powders were derived from the polyacrylamide gel method.The results show that,the wet gels prepared by polyacrylamide perform a unique crystallization behavior in the process of drying,comparing with some customary preparation such as melt processing.The main crystal phase and crystallization sequence of Li2O-Al2O3-SiO2 micro-powders have no distinct with addition of Eu2O3,Gd2O3 or Er2O3,while the crystallization temperature of the β-spodumene decreased and the amount of the β-spodumene increased. 展开更多
关键词 Li2O-Al2O3-SiO2 glass-ceramic powders polyacrylamide gel rare-earth oxides crystallization behavior
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Study on Morphology and Non-isothermal Crystallization Behavior of Poly(phenylene sulfide)/Poly(ethylene-co-cyclo-hexane 1,4-dimethanol terephthalate) Blend 被引量:1
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作者 Shi Jun Chen Yanming Chen Ying 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2010年第1期61-66,共6页
A binary alloy consisting of poly(phenylene-sulfide) (PPS)/poly(ethylene terephthalate-co-l,4- cyclohexanedimethanol) (PETG) was prepared by the melt blending technology using a twin-screw extruder. The morpho... A binary alloy consisting of poly(phenylene-sulfide) (PPS)/poly(ethylene terephthalate-co-l,4- cyclohexanedimethanol) (PETG) was prepared by the melt blending technology using a twin-screw extruder. The morphology and crystallization behavior of the alloy material were investigated by means of SEM, POM and DSC. The SEM study of the alloy samples revealed that PPS and PETG comprised an incompatible system and the interface structure of two phases could be observed distinctly when the composition of the binary alloy was being changed. The POM results had revealed that incorporation of PETG into PPS could lead to formation of larger spherulite crystals in the course of PPS crystallization, but small and grainy spherulite crystals appeared with further increase in the PETG concentration. The DSC analyses revealed that addition of PETG to the alloy composition could shift the PPS crystallization temperature towards the high-temperature region. 展开更多
关键词 PETG PPS alloy MORPHOLOGY crystallization behavior
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Crystallization behavior of electroless Co-Ni-B alloy plated in magnetic field in presence of cerium 被引量:4
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作者 宣天鹏 章磊 黄芹华 《中国有色金属学会会刊:英文版》 EI CSCD 2006年第2期363-367,共5页
The electrochemical property, chemical composition and crystal structure of electroless Co-Ni-B-Ce alloy plated in general state as well as in magnetic field were studied using potentiometer, plasma emission spectrome... The electrochemical property, chemical composition and crystal structure of electroless Co-Ni-B-Ce alloy plated in general state as well as in magnetic field were studied using potentiometer, plasma emission spectrometer, X-ray diffractometer, transmission electron microscope. The results show that the static potential and polarizability of electroless Co-Ni-B alloy are remarkably improved as the plating is carried out in magnetic field in the presence of a little amount of cerium in plating bath. Because of the action of magnetic field and rare earth element cerium, the boron content in alloy decreases, while cobalt and nickel contents increase. As a result, the amorphous Co-Ni-B alloy transforms to the microcrystalline Co-Ni-B-Ce alloy when the plating is in general state, and the Co-Ni-B alloy makes a crystalline transformation because of the action of magnetic field and rare earth element cerium. 展开更多
关键词 Co-Ni-B合金 晶化 结晶转变 电镀 磁场
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Crystallization behavior of melt-spun NdFeB permanent magnets 被引量:1
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作者 徐晖 倪建森 +3 位作者 朱明原 周邦新 董远达 肖学山 《中国有色金属学会会刊:英文版》 EI CSCD 2002年第4期720-722,共3页
The crystallization behavior of melt spun Nd 8.5 Fe 78 Co 5Cu 1Nb 1B 6.5 ribbons was investigated using dynamic differential scanning calorimetry (DSC) and X ray diffractometry (XRD). It was found that the as spun rib... The crystallization behavior of melt spun Nd 8.5 Fe 78 Co 5Cu 1Nb 1B 6.5 ribbons was investigated using dynamic differential scanning calorimetry (DSC) and X ray diffractometry (XRD). It was found that the as spun ribbons crystallize in two steps: at first the Nd 3Fe 62 B 14 + α Fe phases are formed and subsequently Nd 3Fe 62 B 14 transformed to Nd 2Fe 14 B and α Fe upon heating above 680?℃. The effective activation energy of two crystallization peaks are 332.0?kJ/mol and 470.5?kJ/mol, respectively. As the wheel speed increases, the magnetic properties of the magnet change obviously. When the wheel speed is 18?m/s, the best magnetic properties of the magnet was obtained after the sample was annealed at 690?℃ for 8?min: B r=0.74T, i H c=421.7?kA/m, ( BH ) max =64.5?kJ/m 3. 展开更多
关键词 永磁材料 永久磁铁 钕铁硼 永磁体 晶化
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CRYSTALLIZATION AND MELTING OF POLY(ETHYLENE OXIDE)CONFINED IN NANOSTRUCTURED PARTICLES WITH CROSS-LINKED SHELLS OF POLYBUTADIENE
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作者 Wei-pingGao YuBai 陈尔强 Qi-fengZhou 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2005年第3期275-284,共10页
Small fixed aggregates of a poly(ethylene oxide)-block-polybutadiene diblock copolymer(PEO-b-PB)in THFsolution were obtained by adding a selective solvent for PB blocks,followed by cross-linking the PB shells.Themorph... Small fixed aggregates of a poly(ethylene oxide)-block-polybutadiene diblock copolymer(PEO-b-PB)in THFsolution were obtained by adding a selective solvent for PB blocks,followed by cross-linking the PB shells.Themorphologies of the nanostructured particles with a cross-linked shell were investigated by atomic force microscopy andtransmission electron microscopy.The average behaviors of the PEO crystallization and melting confined within thenanostructured particles were studied by using differential scanning calorimetry experiments.For the deeply cross-linkedsample(SCL-1),the crystallization of the PEO blocks was fully confined.The individual nanoparticles only crystallized atvery low crystallization temperatures(T_cs),wherein the homogenous primary nucleation determined the overallcrystallization rate.For the lightly cross-linked sample(SCL-2),the confinement effect was T_c dependent.At T_c(?)42℃,thecrystallization and melting behaviors of SCL-2 were similar to those of the pure PEO-b-PB diblock copolymer.At T_c>42℃,SCL-2 could form PEO lamellae thicker than those of the pure PEO-b-PB crystallized at the same T_c. 展开更多
关键词 Diblock copolymer AGGREGATES Cross-linking confined crystallization and melting.
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Isothermal Crystallization Kinetics and Melting Behavior of POE-g-MAH Compatibilized PA11/POE Blends
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作者 郭云霞 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第4期702-707,共6页
A new Nylon 11(PA11)/polyethylene-octene(POE) blends compatibilized by maleic anhydride grafted mixture polyethyleneocten(POE-g-MAH) was prepared through melt blending method.The isothermal crystallization kinet... A new Nylon 11(PA11)/polyethylene-octene(POE) blends compatibilized by maleic anhydride grafted mixture polyethyleneocten(POE-g-MAH) was prepared through melt blending method.The isothermal crystallization kinetics and melting behaviors of PA11/POE blends were investigated in detail by differential scanning calorimetry(DSC) and polarized optical microscope.The n values of PA11 blending with POE or POE-g-MAH are almost similar with pure PA11,which indicates that the effect of POE and POE-g-MAH on nucleation and growth of PA11 crystal is slight.The overall crystallization rate of PA11/POE blends are higher than ones of pure PA11 at the same crystallization temperatures,but they decrease significantly when POE-g-MAH is added into PA11/POE blends.DSC heating curves of both PA11 and its blends exhibit two melting peaks,but the two melting peak become weaker when POE-g-MAH is add into PA11/POE blend systems.And the spherulite size is reduced significantly by the addition of POE-g-MAH compared with pure PA11 and PA11/POE blends. 展开更多
关键词 PA11 POE-G-MAH isothermal crystallization melting behavior BLENDS
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STUDIES ON THE MECHANICAL PROPERTIES AND CRYSTALLIZATION BEHAVIOR OF POLYETHYLENE COMPOSITES
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作者 朱进 欧玉春 冯宇鹏 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1995年第3期218-227,共10页
The effects of interfacial modifier on the mechanical, dynamic mechanical properties and crystallization behavior of the polyethylene composites were investigated in the present paper. It was found that the interfacia... The effects of interfacial modifier on the mechanical, dynamic mechanical properties and crystallization behavior of the polyethylene composites were investigated in the present paper. It was found that the interfacial modifer significantly improved the mechanical properties, influenced the dynamic mechanical spectra and slightly changed the crystallization behavior. The results showed that the interfacial modifier changed the dispersion state of dispersed phase of the composites, resulting in different phase structure, which was the major reason leading to different mechanical and crystallization properties. 展开更多
关键词 HDPE INTERFACIAL MODIFIER MECHANICAL PROPERTY crystallization behavior
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Crystallization behavior of Ti_3Al-Nb alloy laser beam welding joints
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作者 李俐群 陈彦宾 +2 位作者 张春丽 雷正龙 徐广印 《中国有色金属学会会刊:英文版》 CSCD 2005年第S2期16-20,共5页
CO2 laser beam welding experiment of Ti3Al-Nb alloy was conducted by adopting overlay welding, the resulting special crystallization phenomenon of welding joint was analyzed. The joints have obvious crystallizing laye... CO2 laser beam welding experiment of Ti3Al-Nb alloy was conducted by adopting overlay welding, the resulting special crystallization phenomenon of welding joint was analyzed. The joints have obvious crystallizing layer phenomenon with clear bond-like contours after laser welding. The results of X-spectrofluorimetry and energy spectrum analysis indicate that the non-uniform distribution of elements exists in crystallizing layer, because the temperature gradient is an important factor that impacts the alloy crystallization behavior. Furthermore, the effects of welding heat source, welding speed, pulse frequency and welding preheat on crystallizing layer distribution were investigated. 展开更多
关键词 Ti3Al-Nb alloy laser WELDING crystallizing LAYER crystallization behavior
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Crystallization Behavior and Thermal Properties of PP/MgAl LDH Nanocomposites Prepared in Non-polar Solution
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作者 CUI Zhe ZHANG Guo-ying QU Bao-jun 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2010年第1期152-156,共5页
Polypropylene(PP)/MgAl layered double hydroxide(MgAl LDH) nanocomposites were synthesized by refluxing PP and dodecyl sulfate-intercalated MgAI LDH[MgAI(DS)] in non-polar xylene. Their structure, thermal and cry... Polypropylene(PP)/MgAl layered double hydroxide(MgAl LDH) nanocomposites were synthesized by refluxing PP and dodecyl sulfate-intercalated MgAI LDH[MgAI(DS)] in non-polar xylene. Their structure, thermal and crystallization properties were studied via X-ray diffraction(XRD), transmission electron microscopy(TEM), thermogravimetric analysis(TGA), differential scanning calorimetry(DSC), and polarized light microscopy(PLM). The nanoscaled dispersion of MgAI(DS) nanolayeres in the PP matrix was verified by the disappearance of the d(003) XRD diffraction peak of MgAI(DS) and observation of TEM image. The DSC data show that the SDS/LDH inorganic components negatively affect the crystallization properties of PP and decrease the size of PP sphcrulites because the inorganic components act as additional nuclei. The PP/MgA1 LDH nanocomposites have a faster charring progress in a temperature range of 250--430 ℃ and a better thermal stability above 320℃ than pure PP. 展开更多
关键词 Layered doubled hydroxide POLYPROPYLENE NANOCOMPOSITE Thermal property crystallization behavior
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Crystallization Behavior of Poly(Tetramethylene Oxide) Influenced by the Crystallization Condition of Poly(Butylene Succinate) in Their Copolymers
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作者 黄勇 LIU Junhong +1 位作者 ZHANG Aimin 周涛 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2019年第2期496-506,共11页
The effect of crystallization conditions of poly(butylene succinate)(PBS) component on the crystallization of poly(tetramethylene oxide)(PTMO) component in their segment block copolymer, with a higher PTMO content(PTM... The effect of crystallization conditions of poly(butylene succinate)(PBS) component on the crystallization of poly(tetramethylene oxide)(PTMO) component in their segment block copolymer, with a higher PTMO content(PTMO mass fraction is 67%), was investigated by DSC and temperature-dependent FTIR. It is found that the isothermal crystallization time(tIC) of PBS has an effect on the crystallization behavior of PTMO component. Perturbation correlation move-window two-dimensional(PCMW2 D) correlation analysis and generalized 2 D correlation analysis(2 DIR) were performed to explore the origin of this phenomenon. The PCMW2 D and 2 DIR results show that the correlation intensity peak observed at around 20 ℃ for PTMO is due to the PTMO chains movements forced by the PBS chains folded movements. If tIC of PBS at temperature of 20 ℃ is prolonged, more PTMO components are incorporated in the region between PBS lamellae and the peak at-7.6 ℃(belonging to less-constricted PTMO chains) changes smaller and even disappears, while the peak at-16.3 ℃ belonging to more-constricted PTMO chains gets bigger. A crystallization model was also established in this study. The results of tensile testing showed that tensile strength slightly increased and elongation at break decreased with increasing heat treatment time at 40 ℃. 展开更多
关键词 PBS/PTMO segment block copolymer crystallization behavior perturbation CORRELATION move-window two-dimensional CORRELATION analysis
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