Isothermal Crystallization Kinetics of Poly(phenylene Sulfide)/ZnO Composites

2012 ◽  
Vol 535-537 ◽  
pp. 243-246 ◽  
Author(s):  
Zhong Hou Zhang ◽  
Wen Xin Zhou ◽  
Ya Dong Li ◽  
Chun Mian Yan
Keyword(s):  
Heterogeneous Nucleation ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Nucleating Agent ◽  
Avrami Equation ◽  
Crystallization Time ◽  
Nano Zno ◽  
Kinetics Of ◽  
Phenylene Sulfide

Poly (phenylene sulfide) (PPS)/nano-ZnO composites were prepared by DAKA miniature blending instrument. Isothermal crystallization behavior of PPS composites at 245°C, 250°C, 255°C and 260°C were investigated by means of DSC. The crystallization time of PPS composites is shorter than which of neat PPS at the same crystallization temperature. The Avrami equation was used to analyze DSC data. Results showed that neat PPS is homogeneous nucleation at lower crystallization temperature, which is heterogeneous nucleation at higher crystallization temperature contrarily. PPS/nano-ZnO composites are heterogeneous nucleation at various crystallization temperature, nano-ZnO particles play a role of nucleating agent.

Isothermal Crystallization Kinetics of Poly (Phenylene Sulfide)/TiO2 Composites

2011 ◽  
Vol 284-286 ◽  
pp. 1909-1912 ◽  
Author(s):  
Zhong Hou Zhang ◽  
Guang Xiu Cao ◽  
Ying Ying Li ◽  
Chun Mian Yan
Keyword(s):  
Heterogeneous Nucleation ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Nucleating Agent ◽  
Avrami Equation ◽  
Crystallization Time ◽  
Isothermal Crystallization Kinetics ◽  
Kinetics Of ◽  
Phenylene Sulfide

Poly (phenylene sulfide) (PPS)/nano-TiO2composites were prepared by DAKA miniature blending instrument. Isothermal crystallization behavior of PPS composites at 245°C, 250°C, 255°C and 260°C were investigated by means of DSC. The crystallization time of PPS composites is shorter than which of neat PPS at the same crystallization temperature. The Avrami equation was used to analyze DSC data. Results showed that neat PPS is homogeneous nucleation at lower crystallization temperature, which is heterogeneous nucleation at higher crystallization temperature contrarily. PPS/nano-TiO2composites are heterogeneous nucleation at various crystallization temperature, nano-TiO2particles play a role of nucleating agent.

Non-Isothermal Crystallization Kinetics of Polyvinyl Alcohol-Graphene Oxide Composites

2013 ◽  
Vol 446-447 ◽  
pp. 206-209
Author(s):  
Cheng Peng Li ◽  
Mary She ◽  
Ling Xue Kong
Keyword(s):  
Graphene Oxide ◽  
Side Effects ◽  
Crystallization Kinetics ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Nucleating Agent ◽  
Crystallization Time ◽  
Isothermal Crystallization Kinetics ◽  
Blending Method ◽  
Kinetics Of

Polyvinlyl alcohol (PVA)/graphene oxide (GO) composites are prepared by solution blending method. And the non-isothermal crystallization kinetics of as-prepared composites is evaluated by differential scanning calorimetry (DSC). The results indicate the graphene oxide can significantly modify the non-isothermal crystallization behavior of the PVA, for instance improved crystallization temperature and prolonged crystallization time. Enhanced crystallization temperature illustrates that GO can act as effective nucleating agent. However, prolonged crystallization time means that GO can retard the whole crystallization. Further kinetics analysis indicates that both the crystallization kinetics of neat PVA and PVA/GO match the Mo model very well. According to the Mo model, during the whole crystallization process, graphene oxide perform as a retardant. In conclusion, graphene oxide can act as effective nucleating agent due to strong interaction bewteen graphene oxide and PVA matrix. On the other hand, graphene oxide loaded may lead to other side effects. This side effects may lead to the retarded crystallization speed finally.

Isothermal Crystallization Kinetics of Polypropylene and Hyperbranched Polyester Blends

2011 ◽  
Vol 396-398 ◽  
pp. 1688-1691
Author(s):  
Qing Chun Fan ◽  
Fei Hong Duan ◽  
Huai Bing Guo ◽  
Tian Wu
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Interfacial Free Energy ◽  
Crystallization Time ◽  
Hyperbranched Polyester ◽  
Isothermal Crystallization Kinetics ◽  
Half Crystallization Time ◽  
Kinetics Of

The isothermal crystallization kinetics of PP with different contents of AB2 hyperbranched polyester(HBP) added has been investigated. The results show that HBP acts as a nucleating agent for PP, and the hyperbranched polyester can decrease the half crystallization time (t1/2) and increase the crystallization rate of PP greatly. The Avrami exponents of PP and nucleated PP are all close to 2.5. Hoffman theory was adopted to calculate the interfacial free energy per unit area perpendicular to PP chains σe of PP and PP/HBP blends.

The Crystallization Kinetics of Polypropylene/Organo Montmorillonite Nanocomposites Modified with Calcium Pimelate

2013 ◽  
Vol 747 ◽  
pp. 749-752
Author(s):  
Nattha Thanomchaem ◽  
Wunpen Chonkaew
Keyword(s):  
Crystallization Kinetics ◽  
Nucleating Agent ◽  
Crystal Form ◽  
Avrami Equation ◽  
Crystallization Time ◽  
Relative Crystallinity ◽  
Twin Screw ◽  
Higher Temperature ◽  
Kinetics Of ◽  
Montmorillonite Nanocomposites

Polypropylene/organo montmorillonite nanocomposites modified with 0.001-0.1 wt% calcium pimelate, a β-nucleating agent, were prepared using twin screw extruder. The effects of calcium pimelate content on crystallization behavior were investigated using differential scanning calorimeter (DSC). The crystallization kinetics were studied using both nonisothermal and isothermal methods. The development of relative crystallinity with the crystallization time was analyzed by the Avrami equation. For nonisothermal studies, the Kissingers theory was employed and the crystallization activation energy was calculated. The results showed that the crystallization temperature shifted to a higher temperature range when calcium pimelate was added. The alpha crystal form of polypropylene nanocomposite was suppressed, by the additions of calcium pimelate, while beta crystallization reaction was accelerated.

scholarly journals Non-Isothermal Crystallization Kinetics of Poly(Ethylene Glycol)–Poly(l-Lactide) Diblock Copolymer and Poly(Ethylene Glycol) Homopolymer via Fast-Scan Chip-Calorimeter

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1156
Author(s):  
Dejia Chen ◽  
Lisha Lei ◽  
Meishuai Zou ◽  
Xiaodong Li
Keyword(s):  
Ethylene Glycol ◽  
Heterogeneous Nucleation ◽  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Poly Ethylene Glycol ◽  
Ozawa Method ◽  
Isothermal Crystallization Kinetics ◽  
Fast Cooling ◽  
Poly Ethylene ◽  
Kinetics Of

The non-isothermal crystallization kinetics of double-crystallizable poly(ethylene glycol)–poly(l-lactide) diblock copolymer (PEG-PLLA) and poly(ethylene glycol) homopolymer (PEG) were studied using the fast cooling rate provided by a Fast-Scan Chip-Calorimeter (FSC). The experimental data were analyzed by the Ozawa method and the Kissinger equation. Additionally, the total crystallization rate was represented by crystallization half time t1/2. The Ozawa method is a perfect success because secondary crystallization is inhibited by using fast cooling rate. The first crystallized PLLA block provides nucleation sites for the crystallization of PEG block and thus promotes the crystallization of the PEG block, which can be regarded as heterogeneous nucleation to a certain extent, while the method of the PEG block and PLLA block crystallized together corresponds to a one-dimensional growth, which reflects that there is a certain separation between the crystallization regions of the PLLA block and PEG block. Although crystallization of the PLLA block provides heterogeneous nucleation conditions for PEG block to a certain extent, it does not shorten the time of the whole crystallization process because of the complexity of the whole crystallization process including nucleation and growth.

Study on Non-Isothermal Crystallization Kinetic of Tundish Covering Fluxes

2011 ◽  
Vol 266 ◽  
pp. 102-105
Author(s):  
Li Feng Sun ◽  
Hong Po Wang ◽  
Chun Lai Liu ◽  
Yong Zou ◽  
Mao Fa Jiang
Keyword(s):  
Isothermal Crystallization ◽  
Heat Insulation ◽  
Crystallization Kinetic ◽  
Avrami Equation ◽  
Crystallization Time ◽  
Resistance Furnace ◽  
Crystallization Behaviors ◽  
Good Heat ◽  
Casting Production ◽  
Electrical Resistance Furnace

Basic tundish covering flux is widely used in continuous casting production of high quality steel because of good heat insulation function and the properties of absorbing inclusions. However, there is a serious problem of incrustation caused by basic tundish covering flux in process of pouring and it could be dramatically influenced by the crystallization behaviors of covering flux. In the paper, the crystallization time and ratio of basic tundish covering fluxes were investigated by high temperature electrical resistance furnace and single hot thermocouple apparatus. Based on the crystallization kinetic knowledge and experimental results, Avrami equation was modified, the non-isothermal crystallization equation that could quantitatively describe the crystallization behaviors of basic tundish covering fluxes was established.

Effect of Arenga Pinnata “Ijuk” Fiber as Nucleating Agent on Crystallization Kinetics of Impact Polypropylene Copolymer

2018 ◽  
Vol 923 ◽  
pp. 56-60 ◽  
Author(s):  
Mochamad Chalid ◽  
Evana Yuanita ◽  
Ghiska Ramahdita ◽  
Jaka Fajar Fatriansyah
Keyword(s):  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Nucleating Agent ◽  
Avrami Equation ◽  
Nucleating Agents ◽  
Impact Polypropylene Copolymer ◽  
Kinetics Of

Impact Polypropylene Copolymer (IPC) is one of the PP type which is widely used. IPC was made with addition of ethylene in PP which decreases PP crystallinity. Many efforts have been made to improve the properties of PP crystallinity by addition of nucleating agents. In this study, we use Arenga Pinnata “Ijuk” fiber as PP nucleating agent. In order to determine the effect of “Ijuk” fiber as nucleating agents in kinetics aspect, we used DSC measurement based on Avrami equation. The results showed that the addition of ijuk decreases crystallizationhalf timeand dimension of crystal growth which indicate the effects of “Ijuk” fiber as a nucleating agent.

Kinetics of crystallization for polypropylene/polyethylene/halloysite nanotube nanocomposites

2018 ◽  
Vol 33 (4) ◽  
pp. 451-463 ◽  
Author(s):  
MY Ong ◽  
WS Chow
Keyword(s):  
Crystallization Rate ◽  
Avrami Equation ◽  
Crystallization Time ◽  
Halloysite Nanotube ◽  
Kissinger Equation ◽  
Polyethylene Blends ◽  
Instantaneous Nucleation ◽  
Half Crystallization Time ◽  
T Values ◽  
Kinetics Of

The aim of this study is to investigate the kinetics of non-isothermal crystallization of polypropylene/high-density polyethylene/halloysite nanotube (PP/HDPE/HNT) nanocomposites using three methods, that is, Avrami equation, combined Ozawa–Avrami method (hereafter called Mo model), and Kissinger equation. The Avrami exponent ( n) is in the range of 1–2 for all the PP/HDPE/HNT nanocomposites indicating instantaneous nucleation while the crystallization rate constant ( Zt) values of PP/HDPE increased with the addition of HNT. This proved that addition of HNT increases the crystallization rate. The reduction of half crystallization time ( t 1/2) for PP/HDPE as the increasing HNT loading indicates faster crystallization rate. In the Mo model, the cooling rate chosen at unit crystallization time F( T) values for PP/HDPE decreases with the addition of HNT. Kissinger equation showed that the activation energy ( E a) of crystallization for the PP/HDPE decreases with the addition of HNT. All the results demonstrated that HNT can accelerate the crystallization rate for the PP/polyethylene blends.

scholarly journals The effect of isothermal crystallization on mechanical properties of poly(ethylene 2,5-furandicarboxylate)

e-Polymers ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 1-11
Author(s):  
Wei Zhang ◽  
Qingyin Wang ◽  
Gongying Wang ◽  
Shaoying Liu
Keyword(s):  
Mechanical Properties ◽  
Intrinsic Viscosity ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Tensile Modulus ◽  
Optical Microscope ◽  
Crystallization Time ◽  
Scanning Calorimetry ◽  
Crystallization Properties ◽  
Poly Ethylene

Abstract The effects of isothermal crystallization temperature/time on mechanical properties of bio-based polyester poly(ethylene 2,5-furandicarboxylate) (PEF) were investigated. The intrinsic viscosity, crystallization properties, thermal properties, and microstructure of PEF were characterized using ubbelohde viscometer, X-ray diffraction, polarizing optical microscope, differential scanning calorimetry, and scanning electron microscopy. The PEF sample isothermal crystallized at various temperatures for various times was denoted as PEF-T-t. The results showed that the isothermal crystallization temperature affected the mechanical properties of PEF-T-30 by simultaneously affecting its crystallization properties and intrinsic viscosity. The isothermal crystallization time only affected the crystallization properties of PEF-110-t. The crystallinity of PEF-110-40 was 17.1%. With small crystal size, poor regularity, and α′-crystal, PEF-110-40 can absorb the energy generated in the tensile process to the maximum extent. Therefore, the best mechanical properties can be obtained for PEF-110-40 with the tensile strength of 43.55 MPa, the tensile modulus of 1,296 MPa, and the elongation at a break of 13.36%.

Morphology, Crystalline Structure and Isothermal Crystallization Kinetics of Polybutylene Terephthalate/Montmorillonite Nanocomposites

2005 ◽  
Vol 13 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Defeng Wu ◽  
Chixing Zhou ◽  
Xie Fan ◽  
Dalian Mao ◽  
Zhang Bian
Keyword(s):  
Activation Energy ◽  
Crystallization Kinetics ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Polymer Chains ◽  
Isothermal Crystallization Kinetics ◽  
Clay Particles ◽  
Nucleation Sites ◽  
Kinetics Of ◽  
Montmorillonite Nanocomposites

The melt intercalation method was employed to prepare poly(butylene terepathalate)/montmorillonite nanocomposites, and their microstructure was characterized by wide angle X-ray diffraction and transmission electron microscopy. The XRD results showed that the crystalline plane such as (010), (111), (100) was smaller than that of pristine PBT, which indicates that the crystallite size of PBT in the nanocomposites could be diminished by adding clay. Moreover, the isothermal crystallization kinetics of PBT and PBT/MMT nanocomposites was investigated by differential scanning calorimetry (DSC). During isothermal crystallization, the development of crystallinity with time was analysed by the Avrami equation. The results show that very small amounts of clay dramatically increased the rate of crystallization and high clay concentrations reduced the rate of crystallization at the low crystallization temperatures. At low concentrations of clay, the distance between dispersed platelets was large so it was relatively easy for the additional nucleation sites to incorporate surrounding polymer, and the crystal nucleus was formatted easily. However, at high concentrations of clay, the diffusion of polymer chains to the growing crystallites was hindered by large clay particles, despite the formation of additional nucleation sites by the clay layers. At the higher crystallization temperature, the crystallization of the nanocomposites was slower than that of the pure PBT under the experimental conditions, which means that with the increase in chains mobility at the high crystallization temperature, the crystal nuclei are harder to format, and the hindering effect of clay particles on the polymer chains was stronger than the nucleating effect of the layers. In addition, the activation energies of crystallization for PBT and its nanocomposites were calculated by the Arrhenius relationship, and the results showed that the nanocomposites with a low clay content had the lower activation energy values than PBT, while high amounts of clay increased the activation energy of PBT.

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