Study on the Isothermal Crystallization Kinetics of Polyvinyl Pyrrolidone/Polyamide 6 Blends

Zhang, Shi Jie; Yi, Tao; Yang, Xin; Cheng, Li

doi:10.4028/www.scientific.net/amr.557-559.1487

Cited by 3 publications

(4 citation statements)

References 14 publications

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“…From Figure , it is obvious that the crystallization exotherms become sharper, and T p c shifts to a higher temperature with a decrease in the cooling rate, especially for PA56-SA-0.5. When the cooling rate is low, there is enough time to activate the nuclei, so the crystallization can be at a higher temperature, which is similar to other nucleated semicrystalline polymers. , Moreover, the particle size of SiO 2 significantly affects the crystallization behavior of nucleated PA56. For example, at a given cooling rate of 10 °C/min, T p c is around 216.9 °C for PA56-SB-0.5; for PA56-SA-0.5, T p c shifts to around 228.17 °C.…”

Section: Results and Discussionmentioning

confidence: 95%

Effect of SiO₂ Particles on the Crystallization and Formation of Hydrogen Bonding in Biobased Polyamide 56

Xun

Huang

et al. 2022

ACS Appl. Polym. Mater.

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As PA56 cannot have 100% intermolecular hydrogen bonds (HBs) regardless of how the molecular chains are arranged, the crystallization properties of PA56 are not as good as those of petroleum-based nylon. To replace petroleum-based nylon and broaden the applications, it is necessary to improve the crystallization properties of PA56 and elaborate the relationship between crystallization and hydrogen bonding. In this work, nano-SiO2 with different particle sizes was chosen as the nucleation agent of biobased PA56, and the isothermal and nonisothermal crystallization of PA56 were investigated by differential scanning calorimetry (DSC). It was shown that SiO2 can significantly improve the crystallization properties of PA56 composites, especially for SiO2 with a smaller size. Furthermore, the influence of SiO2 on the formation of hydrogen bonds during the crystallization process was also studied by in situ Fourier transform infrared (FTIR) spectroscopy. The addition of SiO2 into PA56 plays a role in the increase of the conversion of the free carbonyl group to the hydrogen-bonded carbonyl group, which accelerates the formation of intermolecular HBs. The increase of HBs may be the factor for the improvement of the crystallization rate.

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Section: Results and Discussionmentioning

confidence: 95%

Effect of SiO₂ Particles on the Crystallization and Formation of Hydrogen Bonding in Biobased Polyamide 56

Xun

Huang

et al. 2022

ACS Appl. Polym. Mater.

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“…The crystallization half-time (t1/2) is another important parameter of crystallizat kinetics and represents the crystallization time at which the relative crystallinity achiev 50% [25]. It is calculated as follows: The initial stage at each crystallization temperature is linear, and the Avrami equation is applicable for this part of the graph.…”

Section: The Isothermal Crystallization Kinetics Analyzed Using the A...mentioning

confidence: 99%

“…Moreover, the crystallization rate constant Z t decreased with the increase in T c , which suggests a shift from homogeneous to heterogeneous nucleation at higher T c . The crystallization half-time (t 1/2 ) is another important parameter of crystallization kinetics and represents the crystallization time at which the relative crystallinity achieves 50% [25]. It is calculated as follows:…”

Section: The Isothermal Crystallization Kinetics Analyzed Using the A...mentioning

confidence: 99%

Isothermal and Non-Isothermal Crystallization Kinetics of Poly(ethylene chlorotrifluoroethylene)

Yang

Sun

et al. 2022

Polymers

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The isothermal (IT) and non-isothermal (NIT) crystallization kinetics, morphology, and structure of poly(ethylene chlorotrifluoroethylene) (ECTFE) were investigated via differential scanning calorimetry (DSC), polarized optical microscopy (POM), and wide-angle X-ray diffraction (XRD). The Avrami equation could well describe the overall IT crystallization process of ECTFE, and, furthermore, the overall crystallization rate decreased at higher crystallization temperatures (Tc). The equilibrium melting point for ECTFE was found to be 238.66 °C. The activation energies for IT and NIT crystallization were determined as −137.68 and −120.54 kJ/mol, respectively. The Jeziorny model fitted well with the initial stages of NIT melt crystallization, while deviations from linearity in the later stages of the process were due to the collisions of spherulites. Spherulites of ECTFE organized in a hexagonal crystal system were found. The relative crystalline degree of ECTFE under NIT conditions was about 54.55%, and this decreased with the increase in cooling rate. Moreover, the Ozawa and Mo models were suitable for modeling the overall NIT crystallization process of ECTFE.

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“…The positive properties of expanded polystyrene (EPS) at the same time are a significant obstacle to developing a technology for its disposal. The recycling of expanded thermoplastics by conventional methods such as injection molding and extrusion requires an overcare due to the presence of gas inclusions , which during polymers melting adversely affect the uniformity of moldings and the quality of end products with relatively low productivity of equipment. In this regard, one of the main technological tasks is the development of methods for raw materials preparing that would minimize this negative impact.…”

Section: Introductionmentioning

confidence: 99%

Modified Densified Waste of Expanded Polystyrene and Its Blends With Polyamide 6

Levytskyi

Moravskyi

Masyuk

et al. 2020

Polymer Engineering & Sci

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The regularities of expanded polystyrene (EPS) waste modified by polyvinylpyrrolidone (PVP) with the simultaneous gas release in various solvents were revealed. The upper sorption limit depends on the nature of the solvent, the concentration and molecular mass of the PVP, the temperature of the process, and the apparent density of the EPS. It was established that the sorption limit of PVP increases with increasing of its concentration in the system and decreases with molecular mass increasing. Based on XRD and FTIR analyses, it was determined that materials based on polyamide 6 and EPS modified by PVP have an increased crystallinity degree by 10-15%, a smaller average crystallite size and higher technological compatibility. The addition of PVP-modified EPS contributes to the increase of the yield strength of polyamide 6 by about 5%-10%. The increase of the Vicat softening point by 5-8 K and the surface hardness by 25-30 MPa of materials based on polyamide 6 and modified polystyrene was investigated. It is caused by the redistribution of intermolecular bonds between the components of the blend under by the effect of a uniformly distributed PVP in the EPS resulting in increased compatibility between the components and the compacted structure. POLYM. ENG. SCI., 60:935-943, 2020. * modified EPS; ** degassed EPS. FIG. 7 XRD patterns of mixtures on the basis of PA-6 and EPS: (a) pure PA-6; (b) mixture of PA-6 and modified EPS; (c) mixture of PA-6 and degassed EPS. EPS content 5 wt%. 1-approximation curve of diffraction; 2, 3, 4, 5optimized curves of intensity of reflexes of the planes (200)α-, (002)α-, γ-, and amorphous phase.

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Study on the Isothermal Crystallization Kinetics of Polyvinyl Pyrrolidone/Polyamide 6 Blends

Cited by 3 publications

References 14 publications

Effect of SiO₂ Particles on the Crystallization and Formation of Hydrogen Bonding in Biobased Polyamide 56

Effect of SiO₂ Particles on the Crystallization and Formation of Hydrogen Bonding in Biobased Polyamide 56

Isothermal and Non-Isothermal Crystallization Kinetics of Poly(ethylene chlorotrifluoroethylene)

Modified Densified Waste of Expanded Polystyrene and Its Blends With Polyamide 6

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Study on the Isothermal Crystallization Kinetics of Polyvinyl Pyrrolidone/Polyamide 6 Blends

Cited by 3 publications

References 14 publications

Effect of SiO2 Particles on the Crystallization and Formation of Hydrogen Bonding in Biobased Polyamide 56

Effect of SiO2 Particles on the Crystallization and Formation of Hydrogen Bonding in Biobased Polyamide 56

Isothermal and Non-Isothermal Crystallization Kinetics of Poly(ethylene chlorotrifluoroethylene)

Modified Densified Waste of Expanded Polystyrene and Its Blends With Polyamide 6

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Product

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Effect of SiO₂ Particles on the Crystallization and Formation of Hydrogen Bonding in Biobased Polyamide 56

Effect of SiO₂ Particles on the Crystallization and Formation of Hydrogen Bonding in Biobased Polyamide 56