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 Isothermal Crystallization Kinetics Study of Fully Aliphatic PA6 Copolyamides: Effect of Novel Long-Chain Polyamide Salt as a Comonomer

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 472 ◽  
Author(s):  
Syang-Peng Rwei ◽  
Palraj Ranganathan ◽  
Yi-Huan Lee
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Three Dimensional ◽  
Sebacic Acid ◽  
Crystallization Rate ◽  
Polyamide 6 ◽  
Crystallization Time ◽  
Structure Property ◽  
Isothermal Crystallization Kinetics ◽  
Half Crystallization Time

N1, N6-bis (4-aminobutyl) adipamide (BABA) diamine and sebacic acid (SA), also called BABA/SA polyamide salt, were used in a typical melt polymerization processes of polyamide 6 (PA6) to form a series of PA6-BABA/SA copolyamides. The effects of BABA/SA on the isothermal crystallization kinetics of PA6-BABA/SA were studied for the first time. An isothermal crystallization analysis demonstrates that the PA6-BABA/SA matrix provided a higher crystallization rate and shorter half-crystallization time than virgin PA6 did. The degree of crystallization of the PA6-BABA/SA30 matrix was also the lowest among all of the samples considered herein. This result is attributed to the high nucleation efficacy of a small amount of BABA/SA in the crystallization of PA6. Values of the Avrami exponent (n) from 1.84 to 3.91 were observed for all of the polyamide samples, suggesting that the crystallization was involved via a two- to three-dimensional growth mechanism. These findings deepen our understanding of the structure–property relationship of PA6-BABA/SA copolyamides, favoring their practical application.

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.

scholarly journals Isothermal Crystallization Kinetics of Poly(ethylene oxide)/Poly(ethylene glycol)-g-silica Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 648
Author(s):  
Xiangning Wen ◽  
Yunlan Su ◽  
Shaofan Li ◽  
Weilong Ju ◽  
Dujin Wang
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Poly Ethylene Glycol ◽  
Isothermal Crystallization Kinetics ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Kinetics Of

In this work, the crystallization kinetics of poly(ethylene oxide) (PEO) matrix included with poly(ethylene glycol) (PEG) grafted silica (PEG-g-SiO2) nanoparticles and bare SiO2 were systematically investigated by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM) method. PEG-g-SiO2 can significantly increase the crystallinity and crystallization temperature of PEO matrix under the non-isothermal crystallization process. Pronounced effects of PEG-g-SiO2 on the crystalline morphology and crystallization rate of PEO were further characterized by employing spherulitic morphological observation and isothermal crystallization kinetics analysis. In contrast to the bare SiO2, PEG-g-SiO2 can be well dispersed in PEO matrix at low P/N (P: Molecular weight of matrix chains, N: Molecular weight of grafted chains), which is a key factor to enhance the primary nucleation rate. In particular, we found that the addition of PEG-g-SiO2 slows the spherulitic growth fronts compared to the neat PEO. It is speculated that the interfacial structure of the grafted PEG plays a key role in the formation of nuclei sites, thus ultimately determines the crystallization behavior of PEO PNCs and enhances the overall crystallization rate of the PEO nanocomposites.

Non-Isothermal Crystallization Kinetics of Graphene Oxide-Carbon Nanotubes Hybrids / Polyamide 6 Composites

2019 ◽  
Vol 41 (3) ◽  
pp. 394-394
Author(s):  
Zhi Qiang Wang Zhi Qiang Wang ◽  
Yong Ke Zhao and Xiang Feng Wu Yong Ke Zhao and Xiang Feng Wu
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Cooling Rate ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Polyamide 6 ◽  
Degree Of Crystallinity ◽  
Isothermal Crystallization Kinetics ◽  
Kinetics Of

The hybrids combined by nano-materials with different dimensions usually possess much better enhancement effects than single one. Graphene oxide-carbon nanotubes hybrids / polyamide 6 composites has been fabricated. The non-isothermal crystallization kinetics of the as-prepared samples was discussed. Research results showed that increasing the cooling rate was in favor of increasing the crystallization rate and the degree of crystallinity for the as-prepared samples. Moreover, the crystallization rate was first decreased and then increased with increasing the hybrids loading. Furthermore, the crystallization mechanism was changed with increasing the crystallization temperature and the cooling rate. The nucleation and growth modes of the non-isothermal crystallization could be classified into three different types, according to the Ozawa’s theory. These complicated results could be attributed to the important role of crystallization rate as well as the simultaneous hindering and promoting effects of the as-prepared hybrids. This work has reference values for understanding the crystallization kinetics of the polyamide 6-based composites.

Research in Non-Isothermal Crystallization Kinetics of LDPE and Inorganic Particle Composite Films

2013 ◽  
Vol 830 ◽  
pp. 8-12
Author(s):  
Hui Ling Shen ◽  
Peng Cheng Zhou
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Composite Films ◽  
Interfacial Free Energy ◽  
Nucleation Agent ◽  
Isothermal Crystallization Kinetics ◽  
Inorganic Particle ◽  
Particle Composite ◽  
Blend Films ◽  
Kinetics Of

The low density polyethylene (LDPE)/ethylene-octene copolymer (POE) blend films and LDPE/POE/inorganic particle composite films were prepared. By means of DSC method, the crystallization capability and the non-isothermal crystallization kinetics of LDPE composite films were investigated, the results show that the addition of DE can reduce the interfacial free energy of the crystal and the active energy of a nucleus, resulting in stable nuclei can be formed at lower supercooling, which makes the polymer crystallized successfully at high temperatures. By selecting data processing method of Mo ZS and modified Jeziorny, the results indicate that the DE play a role of heterogeneous nucleation agent in the process of crystallization and increased the crystalline rate of LDPE.

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.

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