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Journal of Wuhan University of Technology(Materials Science) 2018年第5期33卷 1247-1255页

作者：王忠强胡国胜 ZHANG Jingting XU Jiusheng SHI Wenbo Institute of Maeromolecules and Bioengineering School of Materials Science and EngineeringNorth University of ChinaTaiyuan 030051China Guangdong Sinoplast Advanced Material Co.Ltd. Dongguan 523860China

Nylon 10T and nylon 10T/1010 samples were synthesized by direct melt polymerization.The isothermal crystallization kinetics of nylon 10T and nylon 10T/1010 was investigated by means of differential scanning calorimetry（DSC）.The crystallization kinetics under isothermal condition has been analyzed by the Avrami equation.It was found that the Avrami equation was well-suited to describe the isothermal crystallization kinetics,combined with the results of the Turnbull-Fisher equation.The values of Tm^0 and Kg were obtained by Hoffman-Weeks and Lauritzen-Hoffman equations,respectively.The activation energies for isothermal crystallization of nylon 10T and nylon 10T/1010 were determined using the Arrhenius equation and found to be-123.24 and-81.86 kJ·mol^（-1）,respectively,which reveals that the crystallization ability of nylon 10T/1010was lower than that of nylon 10T during the isothermal crystallization process.The crystal morphology was observed by means of polarized optical microscopy（POM）and X-ray diffraction（XRD）.It was found that the addition of sebacic acid comonomer did not change the crystal form of nylon 10T,but significantly increased the number and decreased the size of spherulites.

关键词： melt polymerization nylon 10T nylon 10T/1010 semiaromatic polyamides crystallization kinetics isothermal crystallization

isothermal crystallization Kinetics and Melting Behavior of POE-g-MAH Compatibilized PA11/POE Blends

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Journal of Wuhan University of Technology(Materials Science) 2012年第4期27卷 702-707页

作者：郭云霞 Institute of Macromolecules and Bioengineering North University of China

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.

关键词： PA11 POE-g-MAH isothermal crystallization melting behavior blends

INFLUENCE OF SAMPLE THICKNESS ON isothermal crystallization KINETICS OF POLYMERS IN A CONFINED VOLUME

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Chinese Journal of Polymer Science 2005年第6期23卷 657-663页

作者： Hui Sun Zhi-ying Zhang Shi-zhen Wu Bin Yu and Chang-fa Xiao School of Materials Science and Chemical Engineering,Tianjin Polytechnic University,Tianjin 300160,China School of Materials Science and Chemical Engineering Tianjin Polytechnic University Tianjin 300160 China

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.

关键词： Avrami equation isothermal crystallization Confined volume Sample thickness

CHARACTERIZATION OF γ-IRRADIATED CRYSTALLINE POLYMERS Ⅱ isothermal crystallization KINETICS OF γ-RADIATION INDUCED CROSSLINKED POLYAMIDE 1010

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Chinese Journal of Polymer Science 1989年第1期7卷 54-65页

作者：冯金华张利华陈东霖 Changchun Institute of Applied Chemistry Academia Sinica

Polyamide 1010 is a γ-radiation crosslinkable polymer. After irradiation, it is possible to raise its service temperature up to 240℃ . Network formation greatly changes the crystallization behaviour of the polymer. In the present work, DSC was used to examine its isothermal crystallization kinetics. It is found that in addition to the necessity of more undercooling and the lowering of crystallization rate, the primary crystallization stage of the irradiated polymer is shortened. This effect is more evident with increasing radiation dose and content of enhanced difunctionai erosslinking agent. However, the crystallization mechanism of the primary stage is not changed as evidenced by the constancy of Avrami exponent. The lamella end surface free energy σ_e calculated according to Hoffman's equation is very sensitive to γ-radiation. It increases abruptly in 2—3 fold even though the radiation dose is not high enough. The origin of this phenomenon may be accounted for in terms of network structure of the polymer.

关键词： γ-Irradiation Crosslinking Polyamide 1010 isothermal crystallization

Kinetics of Nonisothermal and isothermal crystallization of Metallocene Polyethylene

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Chinese Chemical Letters 1999年第2期10卷 175-178页

作者： Yu Ying LI Ji Jun ZENG Jia Song HE(State Key Laboratory of Engineering Plastics, Institute of Chemistry,The Chinese Academy of Sciences. Beijing 100080) State Key Lab. of Eng. Plastics Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

The kinetics of nonisothermal and isothermal crystallization of metallocene catalyzed and conventional polyethylenes has been studied by differential scanning calorimetry. Using Avrami equation, Ozawa theory and Mo Zhishen method, the experimental data have been analyzed. It is shown that metallocene polyethylene possesses a higher rate of crystallization due to a higher stereoregularity of its molecular chains. Moreover, they have different nonisothermal crystallization mechanisms and identical isothermal crystallization mechanisms.

关键词： metallocene polyethylene nonisothermal crystallization isothermal crystallization

isothermal crystallization Kinetics of Poly（Ethylene Terephthalate） Modified by Calcium Lignosulfonate

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Isothermal Crystallization Kinetics of Poly（Ethylene Tereph...

isothermal and Non-isothermal crystallization Kinetics of Conductive Polyvinylidene Fluoride/Poly(Ethylene Terephthalate) Based Composites

2011 IEEE International Conference on Waste Recycling,Ecology and Environment(ICWREE 2011)

作者： Hanbing MA1 2* Xiuyun LI 1 2 Li YANG 1 2 Detian LIAO 1 Shaoliang XIE 1 1 State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials Mianyang 621010 China 2 National Insulating Material Engineering Research Sub-Center Southwest University of Science and Technology Mianyang 621010 China

In this study, the effect of Lignosulfonate（LS） skeleton presence on the isothermal crystallization speed of the Poly（ethylene terephthalate）（PET） molecular chains were investigated by using differential scanning calorimetry （DSC）. The isothermal crystallization kinetics of PET and modified PET were analyzed by the Avrami equation. The results indicated that the crystallization rate increased with the addition of LS but decreased with overmuch LS. The Arvami exponent decreasing along with the adding of LS suggested that the crystallization changed from two-dimensional disk-shaped growth to three-dimensional spherulite growth. In addition, the introduction of LS made it less sensitive to the crystallization temperature of the blends.

关键词： Poly（Ethylene Terephthalate） Calcium Lignosulfonate isothermal crystallization crystallization kinetics

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Materials Sciences and Applications 2016年第1期7卷 8-19页

作者： Nafaa Athmouni Jianbin Song Frej Mighri Saïd Elkoun Research Center for High Performance Polymer and Composite Systems CREPEC Laval University Quebec Canada Department of Chemical Engineering Laval University Quebec Canada Department of Material Science and Technology Nanjing University of Technology Nanjing China Department of Mechanical Engineering Sherbrooke University Sherbrooke Canada

This work deals with isothermal and non-isothermal crystallization kinetics of electrically conductive polyvinylidene fluoride/poly(ethylene terephthalate) (PVDF/PET) based composites. It completes our previous work in which we related the crystallinity of these conductive PVDF/PET based composites to their through-plane resistivity [1]. isothermal crystallization was described using the logarithmic form of the Avrami equation and it was observed that the crystallization rate of the PVDF phase inside the composite became slower compared to that of neat PVDF. In non-isothermal crystallization, the Avrami exponent of PVDF phase did not show any noticeable variation;however, that of PET phase, which contains the major part of the conductive carbon black (CB) and graphite (GR) additives, showed an evident decrease compared with neat PET. It was also observed that, at the same cooling rate, the crystallization rate of PVDF and PET phases inside the composite was slower than that of neat PVDF and PET.

关键词： isothermal crystallization Non-isothermal crystallization PVDF PET crystallization Kinetics Avrami Model Bipolar Plate

Experimental and Data Fitting Guidelines for the Determination of Polymer crystallization Kinetics

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维普期刊数据库

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Chinese Journal of Polymer Science 2022年第6期40卷 658-691页

作者： Ricardo Arpad Perez-Camargo Guo-Ming Liu Du-Jin Wang Alejandro J.Muller Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Engineering PlasticsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China POLYMAT and Department of Polymers and Advanced Materials:Physics Chemistry and TechnologyFaculty of ChemistryUniversity of the Basque Country UPV/EHUDonostia-San Sebastián 20018Spain IKERBASQUE Basque Foundation for ScienceBilbao 48013Spain

The crystallization kinetics of semicrystalline polymers is often studied with isothermal experiments and analyzed by fitting the data with analytical expressions of the Avrami and Lauritzen and Hoffman(LH)theories.To correctly carry out the analysis,precautions in both experiments and data fitting should be taken.Here,we systematically discussed the factors that influence the validity of the crystallization kinetics study.The basic concepts and fundamentals of the Avrami and LH theories were introduced at first.Then,experimental protocols were discussed in detail.To clarify the impact of various experimental parameters,selected common polymers,i.e.,polypropylene and polylactide,were studied using various experimental techniques(i.e.,differential scanning calorimetry and polarized light optical microscopy).Common mistakes were simulated under conditions when non-ideal experimental parameters were applied.Furthermore,from a practical point of view,we show how to fit the experimental data to the Avrami and the LH theories,using an Origin■App developed by us.

关键词： isothermal crystallization Avrami equation Lauritzen and Hoffman theory Thermal analysis Step-crystallization

Effects of Branches on the crystallization Kinetics of Polypropylene-gPolystyrene and Polypropylene-g-Poly(n-butyl acrylate) Graft Copolymers with Well-defined Molecular Structures

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Chinese Journal of Polymer Science 2014年第3期32卷 333-349页

作者： Lu Wang Zhi-wei Jiang Feng Liu Zhi-jie Zhang 唐涛 State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of Sciences University of Chinese Academy of Sciences

Effects of branches on the crystallization kinetics of polypropylene-g-polystyrene （PP-g-PS） and polypropylene-g- poly（n-butyl acrylate）（PP-g-PnBA） graft copolymers with well-defined molecular structures were systematically investigated by DSC. The Avrami equation was used to analyze the isothermal crystallization process, while the analysis of nonisothermal crystallization process was based on the Jeziorny-modified Avrami model and Mo model. The kinetics results of isothermal and nonisothermal crystallization verified the peculiar effects of branches on the crystallization process of PP backbones in PP-g-PS and PP-g-PnBA graft copolymers： on one hand, the interaction between branches （n-n interaction between PS branches, or dipole-dipole interaction between PnBA branches） restrained the mobility and reptation ability of the PP backbones, which hindered the crystallization process; on the other hand, the heterogeneous nucleation effect resulting from the branched structure and fluctuation-assisted nucleation mechanism （caused by microphase separation between the PS or PnBA rich phase and the PP rich phase） became more pronounced with increasing branch length, which facilitated the crystallization process.

关键词： Polypropylene Polypropylene-g-polystyrene graft copolymer Polypropylene-g-poly（n-butyl acrylate） graftcopolymer isothermal crystallization Nonisothermal crystallization.

Studies on Kinetics of crystallization of PA6/UFAPR Composites

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Chemical Research in Chinese Universities 2003年第4期19卷 464-469页

作者： DING Xue-jia XU Ri-wei ZHANG Bing-wei YU Ding-sheng CHEN Hong Key Laboratory of Preparation and Processing of Novel Polymer of Beijing City College of Materials Science&EngineeringBeijing University of Chemical TechnologyBeijing 100029P.R.China

The influence of Ultrafine Full-Vulcanized Acrylate Powdered Rubber(UFAPR) on the isothermal crystallization kinetics and nonisothermal crystallization behavior of PA6 has been studied by means of DSC. The results show that with the introduction of a small amount of UFAPR, the crystallization rate of PA6 can be increased obviously, and the crystallization temperature range can be augmented and the crystallite size distribution of the crystal can be narrowed down. The change of free energy perpendicular to the crystal nucleus, which has been calculated according to the Hoffman theory, is consistent with the result of Avrami′s equation. The unit surface free energy of the radial-developing crystal spherulite decreases while the crystallization rate of PA6 increases with the introduction of UFAPR. Meanwhile, it is shown by means of the polarizing microscope(PLM) that the crystal size drops down and the number of the crystal grains augments with the addition of UFAPR, which shows that UFAPR can function as a nucleating agent.

关键词： PA6 UFAPR isothermal crystallization Nonisothermal crystallization crystallization kinetics