Evaluating the non-isothermal crystallization behavior of organic molecules from the undercooled melt state using rapid heat/cool calorimetry

CrystEngComm ◽  
2013 ◽  
Vol 15 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Jared A. Baird ◽  
Leonard C. Thomas ◽  
Steven R. Aubuchon ◽  
Lynne S. Taylor
Keyword(s):  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Organic Molecules ◽  
Undercooled Melt

Isothermal crystallization behavior of poly(L-lactic acid)/organo-montmorillonite nanocomposites

2009 ◽  
Vol 30 (9) ◽  
pp. 1338-1344 ◽  
Author(s):  
Xiaoxiu Li ◽  
Jingbo Yin ◽  
Zhenyang Yu ◽  
Shifeng Yan ◽  
Xiaochun Lu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Montmorillonite Nanocomposites

The non-isothermal crystallization behavior of polyamide 6 and polyamide 6/HDPE/MAH/L-101 composites

2019 ◽  
Vol 39 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Bingxiao Liu ◽  
Guosheng Hu ◽  
Jingting Zhang ◽  
Zhongqiang Wang
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Isothermal Condition ◽  
Crystallization Rate ◽  
Polyamide 6 ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Analysis And Design ◽  
Processing Techniques

AbstractStudy of the crystallization kinetics is particularly necessary for the analysis and design of processing operations, especially the non-isothermal crystallization behavior, which is due to the fact that most practical processing techniques are carried out under non-isothermal conditions. The non-isothermal crystallization behaviors of polyamide 6 (PA6) and PA6/high-density polyethylene/maleic anhydride/2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (PA6/HDPE/MAH/L-101) composites were investigated by differential scanning calorimetry (DSC). The crystallization kinetics under non-isothermal condition was analyzed by the Jeziorny and Mo equations, and the activation energy was determined by the Kissinger and Takhor methods. The crystal structure and morphology were analyzed by wide-angle X-ray diffraction (WXRD) and polarized optical microscopy (POM). The results indicate that PA6/HDPE/MAH/L-101 has higher crystallization temperature and crystallization rate, which is explained as due to its heterogeneous nuclei.

Isothermal Crystallization Behavior of Poly (L-lactic Acid)/ Surface-Grafted Silica Nanocomposites

2012 ◽  
Vol 268-270 ◽  
pp. 37-40 ◽  
Author(s):  
Yan Hua Cai
Keyword(s):  
Lactic Acid ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Nucleating Agent ◽  
Melt Blending ◽  
Scanning Calorimetry ◽  
Silica Nanocomposites ◽  
Induction Periods ◽  
Sio2 Nanocomposites ◽  
Different Content

The Poly(L-lactic acid)(PLLA)/surface-grafting silica(g-SiO2) nanocomposites were prepared by melt blending. The isothermal crystallization behavior of PLLA/g-SiO2 nanocomposites with different content of g-SiO2 was investigated by optical depolarizer. In isothermal crystallization from melt, the induction periods and half times for overall PLLA crystallization (95°C Tc 120°C) were affected by the crystallization temperature and the content of g-SiO2 in nanocomposites. The results showed that g-SiO2 as a kind of heterogeneous nucleating agent can reduce induction periods and half times for overall PLLA crystallization. The thermal properties of PLLA/g-SiO2 samples were also investigated by differential scanning calorimetry (DSC), The results showed that the crystalline degree of PLLA was improved as the presence of g-SiO2.

scholarly journals The effect of hydroxyapatite nanoparticles on crystallization and thermomechanical properties of PLLA matrix

2017 ◽  
Vol 89 (1) ◽  
pp. 125-140 ◽  
Author(s):  
Ioanna-Georgia I. Athanasoulia ◽  
Maximos N. Christoforidis ◽  
Dimitrios M. Korres ◽  
Petroula A. Tarantili
Keyword(s):  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Crystallization Kinetic ◽  
Crystallization Rate ◽  
Melting Behavior ◽  
Thermomechanical Properties ◽  
Cold Crystallization ◽  
Crystallization Experiments ◽  
Twin Screw

AbstractIn this study, hydroxyapatite (HA) was incorporated in a poly(L-lactic acid) (PLLA) matrix and the thermal properties and crystallization behavior of the derived composites were investigated. The nanocomposites, containing 0–20 wt% HA, were prepared by melt extrusion employing a twin-screw extruder. XRD experiments verified an increase in the intensity of the characteristic diffraction peak of the α-form crystalline phase of PLLA with increasing HA content. By DSC experiments it was observed that the presence of HA increased the crystallinity during cold crystallization, leading to a shift of cold-crystallization temperature to lower values and to an increase in the melting temperature of the PLLA phase. Isothermal crystallization experiments at 100, 110, 115 and 120°C, revealed a maximum in crystallization kinetic around 100°C after the addition of HA compared to 115°C for pure PLLA. The crystallization rate of PLLA matrix in the nanocomposites decreased with increasing crystallization temperature. By using the Avrami and Lauritzen-Hoffman equations the exponent n was calculated in the range 2–3 and a theoretical approach verified that the HA/PLLA systems belong to Regime II of crystallization behavior. The investigated melting behavior of PLLA was attributed to better organized crystalline structure with increasing isothermal crystallization temperatures and might be related with the longer time necessary for the completion of crystallization.

Unique Isothermal Crystallization Behavior of Novel Polyphenylene Sulfide/Inorganic Fullerene-like WS2Nanocomposites

2008 ◽  
Vol 112 (47) ◽  
pp. 14819-14828 ◽  
Author(s):  
Mohammed Naffakh ◽  
Carlos Marco ◽  
Marián A. Gómez ◽  
Ignacio Jiménez
Keyword(s):  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Polyphenylene Sulfide ◽  
Inorganic Fullerene

Comparative study of the crystallization behavior and morphologies of carbon and glass fiber reinforced poly(ether ether ketone) composites

2020 ◽  
pp. 096739112096510
Author(s):  
Pan Wang ◽  
Qing Lin ◽  
Yaming Wang ◽  
Chuntai Liu ◽  
Changyu Shen
Keyword(s):  
Carbon Fiber ◽  
Glass Fiber ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Unit Cell ◽  
Fiber Reinforced ◽  
Scanning Calorimetry ◽  
Avrami Model ◽  
X Ray ◽  
Glass Fiber Reinforced

This work aims to perform a systematic investigation on the crystallization behavior and morphologies of carbon and glass fiber reinforced PEEK. The nonisothermal and isothermal crystallization behavior was investigated by differential scanning calorimetry (DSC). The resultant morphologies were assessed by wide angle X-ray diffraction (WAXD), small angle X-ray scattering (SAXS), and polarized optical microscopy (POM) to provide details on spherulitic level, crystalline structure at unit cell, and lamellar levels. It was found that the crystallization ability of carbon fiber filled PEEK was better than that of neat PEEK, while the behavior of glass fiber filled PEEK was in an opposite trend. The incorporation of carbon fiber (or glass fiber) led to a looser packing of the unit cell or a less crystal perfection of PEEK but did not change its crystal form as well as its long period of lamellae. The isothermal crystallization kinetics was analyzed by the Avrami model, suggesting that the crystallization mechanism of carbon fiber filled PEEK was different from that of neat PEEK and its glass fiber filled composites. Nevertheless, the POM results showed that fiber-induced transcrystallization in PEEK matrix was not evidenced for either carbon or glass fiber filled PEEK. Finally, the effect of carbon and glass fiber on the crystallization of PEEK matrix was discussed to some extent.

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