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Sanders B, Cant E, Kelly CA, Jenkins M. The Effect of Powder Re-Use on the Coalescence Behaviour and Isothermal Crystallisation Kinetics of Polyamide 12 within Powder Bed Fusion. Polymers (Basel) 2024; 16:612. [PMID: 38475297 DOI: 10.3390/polym16050612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/07/2024] [Accepted: 02/17/2024] [Indexed: 03/14/2024] Open
Abstract
Polymer powder bed fusion (PBF) is becoming increasingly popular for the fabrication of lightweight, high-performance parts, particularly for medical and aerospace applications. This study investigates the effect of powder re-use and material aging on the coalescence behaviour, melt flowability, and isothermal crystallisation kinetics of polyamide-12 (PA-12) powder. With increased powder re-use, a progressive reduction in melt flowability and material coalescence is observed; at 200 °C, the particle consolidation time increases from 15 s in virgin powder to 180 s in powder recovered from build 6. The observed changes in the behaviour of PA-12 were attributed to polycondensation and cross-linking; these aging phenomena also create structural defects, which hinder the rate and extent of primary crystallisation. At an isothermal crystallisation temperature of 165 °C, the crystallisation half-time increased from 12.78 min in virgin powder to 23.95 min in powder re-used across six build cycles. As a result, the commonly used Avrami model was found to be unsuitable for modelling the crystallisation behaviour of aged PA-12 powder, with the co-efficient of determination (R2) reducing from >0.995 for virgin powder to as low as 0.795 for re-used powder. On the other hand, an alternative method, the Hay model, is able to successfully track full phase transformation within re-used powder (R2 > 0.99). These results highlight the importance of selecting the most appropriate model for analysing the crystallisation kinetics of PA-12 powder re-used across multiple build cycles. This understanding is crucial for obtaining the strong mechanical properties and dimensional precision required for the fabrication of functional, end-use parts within PBF.
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Affiliation(s)
- Benjamin Sanders
- School of Metallurgy and Materials, University of Birmingham, Elms Road, Birmingham B15 2SE, UK
| | - Edward Cant
- The Manufacturing Technology Centre, Ansty Park, Coventry CV7 9JU, UK
| | | | - Michael Jenkins
- School of Metallurgy and Materials, University of Birmingham, Elms Road, Birmingham B15 2SE, UK
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Biobased Copolyamides 56/66: Synthesis, Characterization and Crystallization Kinetics. Polymers (Basel) 2022; 14:polym14183879. [PMID: 36146024 PMCID: PMC9504581 DOI: 10.3390/polym14183879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/10/2022] [Accepted: 09/13/2022] [Indexed: 11/25/2022] Open
Abstract
This study synthesized a series of new biobased copolyamides (co-PAs), namely PA56/PA66 with various comonomer ratios, by using in situ polycondensation. The structures, compositions, behaviors, and crystallization kinetics of the co-PAs were investigated through proton nuclear magnetic resonance (1H NMR) spectroscopy, gel permeation chromatography (GPC), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), polarized optical microscopy (POM), and X-ray diffraction (XRD). The influence of the composition of co-PAs on their mechanical properties and thermal stability was investigated. The co-PAs exhibited a eutectic melting point when the PA56 content was 50 mol%, with the crystallization temperature decreasing from 229 to a minimum 188 °C and the melting temperature from 253 to a minimum 218 °C. The results indicated that the tensile strength and flexural modulus first decreased and then increased as the PA66 content increased. The nonisothermal crystallization kinetics of the PA56/PA66 co-PAs were analyzed using both the Avrami equation modifications presented by Jeziorny and Mo. The results also indicated that the crystallization rate of the PA56/PA66 co-PAs was higher than that of PA56.
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Li X, Li X, Wang Y, Zhu P, Wang D, Müller AJ, Dong X. Effect of Initial Molecular Weight on the Structural Evolution of Polyamide 1012 during High-Temperature Thermal Treatments as Revealed by Successive Self-Nucleation and Annealing. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xuan Li
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xueting Li
- Shandong Guangyin New Material Co., Ltd., Zibo, Shandong Province 255022, P. R. China
| | - Yu Wang
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Ping Zhu
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Alejandro J. Müller
- POLYMAT and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizabal 3, Donostia-San Sebastián 20018, Spain
- Ikerbasque, Basque Foundation for Science, Plaza Euskadi 5, Bilbao 48009, Spain
| | - Xia Dong
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Fu X, Dong X, Yang G, Bai S. Non-isothermal crystallization kinetics of graphene/PA10T composites. Heliyon 2022; 8:e10206. [PMID: 36033336 PMCID: PMC9404347 DOI: 10.1016/j.heliyon.2022.e10206] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/10/2022] [Accepted: 08/03/2022] [Indexed: 12/03/2022] Open
Abstract
Crystallization kinetics is the key factor in controlling the polymer crystallization process and affecting crystallinity and crystalline morphology, which determine the polymer's main properties. In this work, the non-isothermal crystallization kinetics of graphene/PA10T composites are investigated by the Jeziorny method and Mo method, and the crystallization activation energy is calculated by the Kissinger method. It is found that the addition of an appropriate amount of graphene to PA10T can significantly promote the crystallization of PA10T and accelerate its crystallization rate. The Jeziorny equation does not have a linear relationship across the whole crystallization range, while the Mo equation does a good linear fitting. In addition, the crystallization activation energy decreases when the graphene content is below 1 wt.%. TGA results indicate that the addition of graphene improves the thermal stability of PA10T.
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Affiliation(s)
- Xubing Fu
- School of Materials Science and Engineering, HEDPS/Center for Applied Physics and Technology, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, PR China
| | - Xia Dong
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, PR China
| | - Guisheng Yang
- Shanghai Genius Advanced Material Co., Ltd., Shanghai 201109, PR China
| | - Shulin Bai
- School of Materials Science and Engineering, HEDPS/Center for Applied Physics and Technology, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing 100871, PR China
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Tseng CH, Tsai PS. The Isothermal and Nonisothermal Crystallization Kinetics and Morphology of Solvent-Precipitated Nylon 66. Polymers (Basel) 2022; 14:442. [PMID: 35160432 PMCID: PMC8840427 DOI: 10.3390/polym14030442] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/16/2022] [Accepted: 01/18/2022] [Indexed: 02/01/2023] Open
Abstract
Solvent-precipitated nylon 66 (SP PA66) is a key material used to fabricate microfiltration membranes. The crystallization kinetics and behavior of SP PA66 were investigated through differential scanning calorimetry (DSC), polarized optical microscopy (POM) and X-ray diffraction (XRD). The Avrami equation was used to describe the isothermal crystallization of SP PA66. Nonisothermal crystallization behaviors were analyzed using Avrami equations modified by Jeziorny, Ozawa and Mo. The Avrami analysis demonstrated that the k values of SP PA66 were higher than those of neat PA66. The n was between 2 and 3 indicating the presence of two- and three-dimensional mode with thermal nucleation. With an increasing cooling rate, the Jeziorny crystallization rate constant increased for SP PA66; however, the Ozawa model was not satisfactory for all SP PA66 samples. The Mo method suggested that SP PA66 had a faster crystallization rate than neat PA66 during the nonisothermal crystallization process. The solvents dissolved nylon 66, rearranged it and formed a regular hydrogen-bonded region. These regions served as nucleation sites and increased the crystallization rate constant in the subsequent melting process. The crystal morphology of the SP PA66 under the POM investigation exhibited Maltese cross spherulites. The sizes of the spherulites of SP PA66 were significantly smaller than those of neat PA66. Wide-angle XRD revealed that SP PA66 had the same crystal structure and a higher crystal perfection than neat PA66.
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Affiliation(s)
- Chiah-Hsiung Tseng
- Department of Chemical and Material Engineering, College of Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 807618, Taiwan
| | - Ping-Szu Tsai
- Department of Chemical and Material Engineering, College of Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 807618, Taiwan
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Sethy S, Samantaray SK, Satapathy BK. Dynamic crystallization behavior of PA-12/PP-MWCNT nanocomposites: non-isothermal kinetics approach. JOURNAL OF POLYMER ENGINEERING 2021. [DOI: 10.1515/polyeng-2021-0195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The effect of multi-walled carbon nanotubes (MWCNT) loading on the crystallization behavior of matrix polyamide 12 (PA-12), in PA-12/polypropylene-MWCNT (PP-MWCNT)-based nanocomposites were analyzed for their non-isothermal crystallization behavior at various cooling rates of 2.5–20 °C/min in differential scanning calorimetry (DSC). Several kinetic models such as Jeziorny (modified-Avrami), Mo and Tobin models were employed to analyze the crystallization behavioral trend with respect to time and temperature of the nanocomposites. The crystallization rate increased half-time of crystallization with MWCNT content as estimated from the Jeziorny theory. The linear agreement between Jeziorny model and experimental relative crystallinity outperforms the Tobin analysis where the coefficient of linear regression was found to be considerably trailing behind and off the satisfactory mark. The Mo model accounts for the percentage crystallinity and thereby successfully explained the crystallization behavior of PA-12 where the kinetic parameters increased with crystallinity indicating higher cooling rate for higher crystallinity. The MWCNT induced crystallization (nucleation activity) values were close to zero irrespective of MWCNT loading which reiterates the enhanced crystallization (rate) of PA-12 in the nanocomposites. Estimations based on Friedman approach showed inter-relationship between activation energy and crystallinity where the later was found to be governed by major (matrix) PA-12 phase.
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Affiliation(s)
- Sucharita Sethy
- Department of Materials Science and Engineering , Indian Institute of Technology Delhi , Hauz Khas , New Delhi 110016 , India
| | - Saroj Kumar Samantaray
- Department of Materials Science and Engineering , Indian Institute of Technology Delhi , Hauz Khas , New Delhi 110016 , India
| | - Bhabani K. Satapathy
- Department of Materials Science and Engineering , Indian Institute of Technology Delhi , Hauz Khas , New Delhi 110016 , India
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Li X, Wang L, Wang D, Müller AJ, Dong X. Competition between Chain Extension and Crosslinking in Polyamide 1012 during High-Temperature Thermal Treatments as Revealed by Successive Self-Nucleation and Annealing Fractionation. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01252] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xuan Li
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Lili Wang
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- State Key Laboratory of Biofibers and Eco-textiles, Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Institute of Marine Biobased Materials, Qingdao University, Qingdao 266071, P. R. China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Alejandro J. Müller
- POLYMAT and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizabal 3, Donostia-San Sebastián 20018, Spain
- Ikerbasque, Basque Foundation for Science, Plaza Euskadi 5, Bilbao 48009, Spain
| | - Xia Dong
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Chen YH, Ranganathan P, Chen CW, Lee YH, Rwei SP. Effect of Bis (2-Aminoethyl) Adipamide/Adipic Acid Segment on Polyamide 6: Crystallization Kinetics Study. Polymers (Basel) 2020; 12:polym12051067. [PMID: 32384761 PMCID: PMC7284434 DOI: 10.3390/polym12051067] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 11/16/2022] Open
Abstract
The crystallization behavior of novel polyamide 6 (PA6) copolyamides with different amounts of bis (2-aminoethyl) adipamide/adipic acid (BAEA/AA) segment was investigated. The wide-angle X-ray diffraction (WAXD) results showed that as the amount of BAEA/AA segment increased to 10 mole%, the crystalline forms of all PA6 copolyamide were transferred from the stable α-form to the unstable γ-form because of the complex polymer structure. According to studies of crystallization kinetics, the Avrami exponent (n) values for all copolyamide samples ranged from 1.43 to 3.67 under isothermal conditions, implying that the crystallization is involved in the two- to three-dimensional growth at a high temperature of isothermal condition. The copolyamides provided a slower crystallization rate and higher crystallization activation energy (ΔEa) than neat PA6. Polyamide containing 10 mole% of BEAE/AA content exhibited a unique crystallization behavior in the coexistence of the α and γ forms. These results deepen our understanding of the relationship between BAEA/AA content, crystal structure, and its crystallization behavior in low-melting PA6, and they make these types of copolyamides useful for their practical application.
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9
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Effect of Supercooling and Shear Stress on the Properties of Polyamide-12. CHEMICAL AND PETROLEUM ENGINEERING 2020. [DOI: 10.1007/s10556-020-00741-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Rheo-Raman spectroscopic study of plasticity and elasticity transformation in poly(ether-block-amide) thermoplastic elastomers. POLYMER 2020. [DOI: 10.1016/j.polymer.2019.122128] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Lin C, Zou F, Fernández‐Ronco MP, Yan Y, Hufenus R. Melting behavior and non‐isothermal crystallization kinetics of copolyamide 6/12. POLYMER CRYSTALLIZATION 2019. [DOI: 10.1002/pcr2.10054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Chao Lin
- Department of Polymer Materials and EngineeringSchool of Materials Science and Engineering, South China University of Technology Guangzhou China
| | - Fei Zou
- Department of Polymer Materials and EngineeringSchool of Materials Science and Engineering, South China University of Technology Guangzhou China
| | - María P. Fernández‐Ronco
- Department of Functional MaterialsEmpa, Swiss Federal Laboratories for Materials Science and Technology St. Gallen Switzerland
| | - Yurong Yan
- Department of Polymer Materials and EngineeringSchool of Materials Science and Engineering, South China University of Technology Guangzhou China
- Department of Functional MaterialsEmpa, Swiss Federal Laboratories for Materials Science and Technology St. Gallen Switzerland
| | - Rudolf Hufenus
- Department of Functional MaterialsEmpa, Swiss Federal Laboratories for Materials Science and Technology St. Gallen Switzerland
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12
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Schawe JE. Identification of three groups of polymers regarding their non-isothermal crystallization kinetics. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.02.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Quantification of isothermal crystallization of polyamide 12: Modelling of crystallization kinetics and phase composition. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.09.037] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Wang H, Zhou F, Wang T, Zhang H, Liu T, Yang Y. Isothermal and nonisothermal crystallization kinetics of poly(ether ether ketone)/gadolinium oxide composites. HIGH PERFORM POLYM 2013. [DOI: 10.1177/0954008313476315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this study, poly(ether ether ketone) (PEEK)/gadolinium oxide (Gd2O3) composites were prepared by melt extrusion in combination with a Haake rheometer. Differential scanning calorimetry was used to investigate the crystallization behavior of PEEK and its corresponding composites. The microstructural features of the composites and the interfacial interactions between the filler and PEEK phases were viewed with a scanning electron microscope. Gd2O3 powder was blended with PEEK, and sulfonated poly(ether ether ketone) (SPEEK) was used as the compatibilizer in the PEEK/Gd2O3 composites. Isothermal crystallization exotherms showed that the addition of SPEEK increased the crystallization of PEEK in PEEK/Gd2O3 composites. However, the PEEK crystallization rates decreased with increasing Gd2O3 fractions, which probably resulted from the Gd2O3 that had no heterogeneous nucleation effects on the matrix. The modified Avrami equation and Mo’s equation were used to study the nonisothermal crystallization kinetics. The addition of Gd2O3 did not change the nucleation process of PEEK, but it markedly decreased the crystal growth rate.
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Affiliation(s)
- Haibin Wang
- Jilin University, Changchun, People’s Republic of China
| | - Fugui Zhou
- Jilin University, Changchun, People’s Republic of China
| | - Tingting Wang
- Jilin University, Changchun, People’s Republic of China
| | - Hang Zhang
- Jilin University, Changchun, People’s Republic of China
| | - Tao Liu
- Jilin University, Changchun, People’s Republic of China
| | - Yanhua Yang
- Jilin University, Changchun, People’s Republic of China
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Xiao X, Zeng Z, Xue W, Kong Q, Zhu W. Isothermal crystallization kinetics and melting behaviors of poly(butylene terephthalate) and poly(butylene terephthalate-co
-fumarate) copolymer. POLYM ENG SCI 2012. [DOI: 10.1002/pen.23287] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Dhanvijay PU, Shertukde VV, Kalkar AK. Isothermal and nonisothermal crystallization kinetics of poly(ϵ-caprolactone). J Appl Polym Sci 2011. [DOI: 10.1002/app.34045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Zeng Z, Zhang H, Xue W, Zhu W, Xiao X, Sun Y, Li Z. Isothermal crystallization kinetics of poly(butylene terephthalate-co-sebacate) copolymer. J Appl Polym Sci 2011. [DOI: 10.1002/app.33814] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Song J, Lu C, Xu D, Ni Y, Liu Y, Xu Z, Liu J. The effect of lanthanum oxide (La2O3) on the structure and crystallization of poly(vinylidene fluoride). POLYM INT 2010. [DOI: 10.1002/pi.2812] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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