Properties and Nonisothermal Crystallization Behavior of Nucleated Polylactide Biodegradable Composite Films

2012 ◽  
Vol 488-489 ◽  
pp. 671-675 ◽  
Author(s):  
Worasak Phetwarotai ◽  
Duangdao Aht-Ong
Keyword(s):  
Tensile Properties ◽  
Cooling Rate ◽  
Crystallization Behavior ◽  
Composite Films ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Precipitated Calcium Carbonate ◽  
Biodegradable Composite

Polylactide biodegradable composite films were prepared via melt extrusion using a twin screw extruder. The effects of type and content of nucleating agent and cooling rate on the thermal and tensile properties of these films were investigated. Two types of nucleating agent, talc and nano precipitated calcium carbonate (NPCC), were studied at various contents from 0 to 2.0 phr. Nonisothermal crystallization behavior of composites was characterized by a differential scanning calorimetry (DSC). The cooling rate was varied from 1 to 10°C/min. The results indicated that the presence of nucleating agent significantly influenced on thermal and tensile properties of the PLA composite films. DSC thermograms revealed that the addition of nucleating agent on the PLA films led to an increase of crystallization temperature (Tc), crystallization rate, and degree of crystallization (χc) compared to the neat PLA. These behaviors could be noticed in both the nucleated PLA films with NPCC and talc. In contrast, the Tc and crystallization half-time (t1/2) of these films significantly decreased when the cooling rate increased from 1 to 10°C/min. However, thermal stability of the films decreased when the nucleating agent content increased, especially that of the composites with NPCC.

The effect of cooling rate on crystallization behavior and tensile properties of CF/PEEK composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guangming Dai ◽  
Lihua Zhan ◽  
Chenglong Guan ◽  
Minghui Huang
Keyword(s):  
Cooling Rate ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystalline Polymer ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Cooling Rates ◽  
Control Range ◽  
Temperature Range ◽  
Transverse Tensile

Abstract In this study, the differential scanning calorimetry (DSC) tests were performed to measure the nonisothermal crystallization behavior of carbon fiber reinforced polyether ether ketone (CF/PEEK) composites under different cooling rates. The characteristic parameters of crystallization were obtained, and the nonisothermal crystallization model was established. The crystallization temperature range of the material at different cooling rates was predicted by the model. The unidirectional laminates were fabricated at different cooling rates in the crystallization temperature range. The results showed that the crystallization temperature range shifted to a lower temperature with the increase of cooling rate, the established nonisothermal crystallization model was consistent with the DSC test results. It is feasible to shorten the cooling control range from the whole process to the crystallization range. The crystallinity and transverse tensile strength declined significantly with the increase of the cooling rate in the crystallization temperature range. The research results provided theoretical support for the selection of cooling conditions and temperature control range, which could be applied to the thermoforming process of semi-crystalline polymer matrixed composites to improve the manufacturing efficiency.

scholarly journals Thermal and Mechanical Properties of Silica–Lignin/Polylactide Composites Subjected to Biodegradation

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2257 ◽  
Author(s):  
Aleksandra Grząbka-Zasadzińska ◽  
Łukasz Klapiszewski ◽  
Sławomir Borysiak ◽  
Teofil Jesionowski
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Crystallization Behavior ◽  
Composite Films ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Hybrid Filler ◽  
Hybrid Fillers ◽  
Morphology Of Films

In this paper, silica–lignin hybrid materials were used as fillers for a polylactide (PLA) matrix. In order to simulate biodegradation, PLA/hybrid filler composite films were kept in soil of neutral pH for six months. Differential scanning calorimetry (DSC) allowed analysis of nonisothermal crystallization behavior of composites, thermal analysis provided information about their thermal stability, and scanning electron microscopy (SEM) was applied to define morphology of films. The influence of biodegradation was also investigated in terms of changes in mechanical properties and color of samples. It was found that application of silica–lignin hybrids as fillers for PLA matrix may be interesting not only in terms of increasing thermal stability, but also controlled biodegradation. To the best knowledge of the authors, this is the first publication regarding biodegradation of PLA composites loaded with silica–lignin hybrid fillers.

scholarly journals Crystallization Behavior of Polyvinyl Alcohol With Inorganic Nucleating Agent Talc and Regulation Mechanism Analysis

2021 ◽  
Author(s):  
Ruru Huang ◽  
Yane Zhang ◽  
Aimin Xiang ◽  
Songbai Ma ◽  
huafeng tian ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Melt Processing ◽  
Avrami Equation ◽  
Hydroxyl Groups ◽  
Regulation Mechanism ◽  
Mechanism Analysis ◽  
Scanning Calorimetry

Abstract Polyvinyl alcohol (PVA) decompose before melting, making it difficult for melt processing. This phenomenon limits the applications of PVA. Therefore, to widen the application of PVA, in the present work, the PVA films have been prepared by the flow casting method. And talc added as an inorganic nucleating agent to improve the crystallinity of PVA. The effects of talc on the crystallization behavior of PVA are tested by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and successive self-nucleation annealing (SSA). The crystallization kinetics behavior of talc was is further studied by Mo Zhishen equation and Avrami equation. The results show that the addition of talc to the PVA film promotes its crystallization, and as the content of the nucleating agent increases, the crystallinity tends to increase, and the thickness of the wafer becomes uniform due to the increase of nucleation points. These results show that talc regulates the crystallization of PVA, improves the crystallinity and crystallization rate of PVA, and has a heterogeneous nucleation effect. PVA itself exhibits hydrophilicity because it contains large number of hydroxyl groups, and has good physical and chemical properties. In addition, the mechanical properties and water resistance have been further improved by improving the crystallinity of PVA, and the practicability of PVA film in actual production was improved.

Nonisothermal crystallization kinetics of polybutene-1 containing nucleating agent with acid amides structure

2014 ◽  
Vol 34 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Yongxian Zhao ◽  
Junyi Chen ◽  
Lei Han ◽  
Le Zhao
Keyword(s):  
Crystallization Process ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Mass Ratio ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Nucleation Effect ◽  
Activation Energy Of Crystallization ◽  
Nonisothermal Crystallization Kinetics ◽  
Kinetics Of

Abstract The nonisothermal crystallization behaviors of virgin isotactic polybutene-1 (iPB-1) and iPBn (iPB-1 containing a nucleating agent that owns acid amides structure; iPB/Mult920=100/0.5, mass ratio) were studied by means of differential scanning calorimetry (DSC). Modified Avrami theories (Ozawa method) and Mo method were used to analyze the DSC date. The results show that both methods are suitable to describe the crystallization process of iPB-1 and iPBn. Addition of 0.5% (mass ratio) nucleating agent can give rise to the nucleation effect, which increases the crystallization temperature (Tc) and the rate of crystallization of iPB-1, decreases the activation energy of crystallization (ΔE), and increases the crystallization rate of iPB-1 under the actual conditions.

The Structure and Nonisothermal Crystallization Kinetics of HDPE Nanocomposites Filled with Mg2Al–LDH

2012 ◽  
Vol 20 (8) ◽  
pp. 701-710 ◽  
Author(s):  
Jun Qin ◽  
Xiaolang Chen ◽  
Jie Yu ◽  
Tian Xie ◽  
Yaozhu Tian ◽  
...  
Keyword(s):  
Crystallization Rate ◽  
Random Copolymer ◽  
Nucleating Agent ◽  
Crystallization Behaviour ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Nonisothermal Crystallization ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Master Batch

High-density polyethylene (HDPE)/Mg2Al–layered double hydroxide (Mg2Al–LDH) nanocomposites with an ethylene-acrylic acid random copolymer (EAA)/Mg2Al–LDH master batch were prepared by melt-mixing. The structure of the nanocomposites was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results demonstrate the formation of the nanocomposites with exfoliated/intercalated layered double hydroxides well distributed in the HDPE matrix. The nonisothermal crystallization behaviour of master batch-based HDPE nanocomposites was studied by using differential scanning calorimetry (DSC). The crystallization behaviour of HDPE/Mg2Al–LDH nanocomposites was well defined by the Avrami analysis and Jeziorny method, as well as the combined Avrami and Ozawa analysis (MO's model). The results reveal that a very small amount of Mg2Al–LDH (1%) accelerates the crystallization process in comparison with the neat HDPE, and the high crystallization rate is attributed to the nucleating effect of the exfoliated nanoparticles. Overall, the exfoliated Mg2Al–LDH particles act as the nucleating agent, and therefore distinctly change the type of nucleation, growth and geometry of HDPE crystals.

Preparation and Nonisothermal Crystallization Behavior Study of PET/PTT/MMT Nanocomposites

2012 ◽  
Vol 518-523 ◽  
pp. 772-774 ◽  
Author(s):  
Li Yan Wang ◽  
Li Ying Guo ◽  
Tao Jiang ◽  
Yan Ming Chen
Keyword(s):  
Crystallization Behavior ◽  
Nucleating Agent ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Behavior Study ◽  
Poly Ethylene Terephthalate ◽  
Twin Screw ◽  
Higher Temperature ◽  
Poly Ethylene ◽  
Crystallization Onset

Abstract. Poly(ethylene terephthalate)(PET)/poly(trimethylene terephthalate) (PTT) and PET/PTT /montmorillonite(MMT) nanocomposites were prepared by melt blending through a co-rotating twin screw extruder. Their morphology was characterized by Scanning Electron Microscope(SEM). And the nonisothermal crystallization behavior was studied by Differential Scanning Calorimetry(DSC). The results indicated that MMT dispersed homogeneously in the PTT matrix; the crystallization onset temperature(Tonset) and the crystallization peak temperature(Tp) in crystallization exotherms of PET/ PTT/MMT nanocomposites shifted to higher temperature as MMT content increased, which proved MMT acted as heterogeneous nucleating agent, and the crystallization behavior became imperfect as the cooling rate increased.

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.

Crystallization Behavior of Polyethylene/Montmorillonite Nanocomposites Prepared by In Situ Polymerization

2012 ◽  
Vol 184-185 ◽  
pp. 932-935
Author(s):  
Min Li ◽  
Li Guang Xiao ◽  
Hong Kai Zhao
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
Crystallization Process ◽  
In Situ Polymerization ◽  
Nucleating Agent ◽  
Lower Content ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
Montmorillonite Nanocomposites

Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The crystallization behavior of PE/MMT nanocomposites at different MMT concentrations (from 0.1 to 1.2 wt %) were investigated by differential scanning calorimetry (DSC). The equilibrium melting points increase by the addition of MMT. The crystallization rates of PE/MMT nanocomposites are faster than those of pure PE. The addition of MMT facilitated the crystallization of PE, with the MMT functioning as a heterogeneous nucleating agent at lower content; at higher concentrations, however, the physical hindrance of the MMT layers to the motion of PE chains retarded the crystallization process.

Role of interfacial interaction on the crystallization behavior and melting characteristics of PP/Nano-CaCO3 composites modified with different compatibilizers

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuhai Wang ◽  
Hao Shen ◽  
Gu Li ◽  
Kancheng Mai
Keyword(s):  
Synergistic Effect ◽  
Heterogeneous Nucleation ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Interfacial Interaction ◽  
Scanning Calorimetry ◽  
Polar Groups ◽  
Melting Characteristics

AbstractPP/nano-CaCO3 composites with different interfacial interaction were prepared by addition of compatibilizers with the same polar groups but different backbones. The non-isothermal and isothermal crystallization behavior of PP/nano- CaCO3 composites was investigated using differential scanning calorimetry (DSC). The results indicated that the interfacial interaction between PP and nano-CaCO3 increased the crystallization temperature and crystallization rate of PP due to the heterogeneous nucleation of nano-CaCO3. The interfacial interaction between nano- CaCO3 and compatibilizer further increased the crystallization temperature and crystallization rate of PP and induced the formation of β-crystal of PP due to the synergistic effect of heterogeneous nucleation between nano-CaCO3 and compatibilizer. This synergistic effect of heterogeneous nucleation between nano- CaCO3 and compatibilizer depended on the interfacial interaction between compatibilizer and PP matrix. The increased compatibility between compatibilizer and PP matrix favoured the heterogeneous nucleation between nano-CaCO3 and compatibilizer

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