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.

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.

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.

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.

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.

scholarly journals Isothermal Crystallization Kinetics of Poly(ethylene terephthalate) Copolymerized with Various Amounts of Isosorbide

2020 ◽  
Vol 10 (3) ◽  
pp. 1046 ◽  
Author(s):  
Nicolas Descamps ◽  
Florian Fernandez ◽  
Pierre Heijboer ◽  
René Saint-Loup ◽  
Nicolas Jacquel
Keyword(s):  
Isothermal Crystallization ◽  
Ethylene Terephthalate ◽  
Systematic Investigation ◽  
Crystallization Time ◽  
Isothermal Crystallization Kinetics ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Half Crystallization Time ◽  
First Time ◽  
Kinetics Of

Poly(ethylene-co-isosorbide terephthalate) (PEIT) copolyesters could be used in various applications depending on their ability to crystallize. Moreover, the possibility to carry out solid-state post-condensation (SSP) is conditioned by its ability to sufficiently crystallize. The present study, thus, gives a systematic investigation of isothermal crystallization of these statistical copolyesters with isosorbide contents ranging from 4.8 to 20.8 mol.%. For each copolyester composition, the lowest isothermal half crystallization times and the highest Avrami constant (K) were obtained around 170 °C. Over the range of composition that was studied, both melting points and melting enthalpies decreased with increasing amounts of isosorbide (from 250 to 207 °C and from 55 to 28 J/g, respectively). On the contrary, half crystallization time displayed an exponential increase when increasing isosorbide contents in the studied range. Finally, structural and thermal analysis of PIT homopolyester are reported for the first time, showing that only ET moieties crystallized when PEIT was subjected to isothermal crystallization at 170 °C.

Effects of Attapulgite on the Isothermal Crystallization Behavior of Poly(Butylene Succinate-co-Butylene Adipate)

2013 ◽  
Vol 791-793 ◽  
pp. 56-59
Author(s):  
Zhi Guo Qi ◽  
Jin Nan Chen ◽  
Bao Hua Guo ◽  
Yu Zhang
Keyword(s):  
Crystallization Kinetics ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Growth Form ◽  
Crystallization Rate ◽  
Melt Mixing ◽  
Butylene Succinate ◽  
Isothermal Crystallization Kinetics ◽  
Kinetics Of

Poly (butylene succinate-co-butylene adipate)/attapulgite nanocomposites were prepared by melt mixing in a HAAKE mixer. The crystallization kinetics of PBSA and its nanocomposites was studied under isothermal conditions by differential scanning calorimetr. The isothermal crystallization kinetics results indicated that attapulgite can induce heterogeneous nucleation, resulting in an improvement on the crystallization temperature and crystallization rate. Both the PBSA and its nanocomposites were correlated to the spherulitic growth form.

The Non-Isothermal Crystallization Kinetics of Dispersible Nano-SiO2/PA66 Composites

2012 ◽  
Vol 535-537 ◽  
pp. 94-102
Author(s):  
Lei Jia ◽  
Li Ping Guo ◽  
Xiang Min Xu
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Activation Energies ◽  
Crystallization Time ◽  
Dsc Analysis ◽  
Screw Extruder ◽  
Isothermal Crystallization Kinetics ◽  
Melt Compounding ◽  
Twin Screw ◽  
Kinetics Of

The PA66-based composites containing dispersible nano-SiO2 (DNS) were prepared in a twin-screw extruder by melt compounding. The microstructures of dispersible nano-SiO2/PA66 composites were investigated by means of TEM and XRD, and the non-isothermal crystallization behavior was studied through Jeziorny method and Mo method based on DSC analysis. The results showed that the dispersion of DNS was uniform in PA66 matrix, which could be related to surface structure of dispersible nano-SiO2. It was found from the study of the non-isothermal crystallization kinetics that dispersible nano-SiO2 possessed a heterogeneous nucleation capability in PA66 matrix, and its addition could hinder the motion of PA66 molecular chain, lower the crystallization temperature, and prolong the crystallization time of PA66. In addition, the activation energies for non-isothermal crystallization of neat PA66 and composites were also evaluated by the Kissinger method. The result showed that the activation energies of dispersible nano-SiO2/PA66 composites were higher than that of neat PA66.

Sign in / Sign up

Export Citation Format

Share Document