scholarly journals Investigations on Novel Ternary Green Polymer Composite

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 31
Author(s):  
Ting-Chia Hsu ◽  
Li-Ting Lee ◽  
Xin-Yun Wu
Keyword(s):  
Electron Microscopy ◽  
Hexagonal Boron Nitride ◽  
Crystallization Rate ◽  
Avrami Equation ◽  
Nucleation Density ◽  
Nucleation Agent ◽  
K Value ◽  
Nucleation Effect ◽  
Poly Ethylene ◽  
Green Polymer

In this study, the novel ternary green polymer composites of poly(l-lactic acid) (PLLA)/poly(ethylene adipate)/hexagonal boron nitride (PLLA/PEA/h-BN) were synthesized and prepared. The crystallization rate of the biodegradable polymer PLLA in the composite was significantly increased with the addition of PEA and functional h-BN. In ternary PLLA/PEA/h-BN composites, PEA can be used as a plasticizer, while h-BN is a functional nucleation agent for PLLA. The analysis of the isothermal crystallization kinetics by the Avrami equation shows that the rate constant k of the ternary PLLA/PEA/h-BN composite represents the highest value, indicating the highest crystallization in the ternary composite. Adding h-BN in the composite can further increase the k value and increase the crystallization rate. Polarized optical microscopy (POM) images reveal that h-BN is an effective nucleation agent that increases the nucleation density of composites. Analysis of wide-angle X-ray diffraction (WAXD) further confirmed that the crystalline structures of PLLA were unchanged by the addition of PEA and h-BN. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show that the h-BN particles are uniformly distributed in the composite. The distribution of h-BN having a particle size of a few hundred nm causes an effective nucleation effect and promotes the crystallization of the ternary composites.

scholarly journals Enhancement of Crystallization Behaviors in Quaternary Composites Containing Biodegradable Polymer by Supramolecular Inclusion Complex

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1137
Author(s):  
Li-Ting Lee ◽  
Sheng-Ping He ◽  
Chih-Feng Huang
Keyword(s):  
Inclusion Complex ◽  
Biodegradable Polymer ◽  
Crystallization Rate ◽  
Water Soluble ◽  
Avrami Equation ◽  
Ternary Blend ◽  
Nucleation Density ◽  
Nucleation Agent ◽  
Water Soluble Polymer ◽  
Poly Ethylene

Novel multi-component composites composed of the biodegradable polymer poly(ethylene adipate) (PEA), the water-soluble polymer poly(ethylene oxide) (PEO), poly(vinyl acetate) (PVAc), and a supramolecular-like inclusion complex (IC) made by α-cyclodextrin (α-CD) and poly(ε-caprolactone) (PCL) (coded as PCL–CD–IC) are discussed in this work. The PCL–CD–IC was used to increase the crystallization rate of the miscible PEA/PEO/PVAc ternary blend that crystalized slower than neat PEA. Higher resolution SEM and TEM images displayed that PCL–CD–IC did not assemble notably in the quaternary composites. For the results of isothermal crystallization, the analysis of the Avrami equation demonstrated that the rate constant k increased with the addition of PCL–CD–IC in the composites, suggesting that PCL–CD–IC provided more nucleation sites to promote the crystallization rate. The nucleation density increased with the addition of PCL–CD–IC, and the amount of spherulite also increased. Wide angle X-ray results showed that the composites displayed similar diffraction patterns to neat PEA, meaning PEO, PVAc, and PCL–CD–IC would not change the crystal structures of PEA in the composites. The PCL–CD–IC, the supramolecular nucleation agent, demonstrated its superior ability to enhance the multi-component composites of biodegradable polymer in this study.

scholarly journals Crystallization Behaviors of Composites Comprising Biodegradable Polyester and Functional Nucleation Agent

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1260
Author(s):  
Li-Ting Lee ◽  
Hsiang-Yun Tseng ◽  
Tzi-Yi Wu
Keyword(s):  
Isothermal Crystallization ◽  
Hexagonal Boron Nitride ◽  
Crystallization Rate ◽  
Avrami Equation ◽  
Crystallization Time ◽  
Nucleation Agent ◽  
Sem Images ◽  
Crystallization Behaviors ◽  
Nucleation Effect ◽  
Xrd Diffraction

In this study, a thorough study of the crystallization behaviors of the biodegradable polymer composites of poly(ethylene succinate) (PESu) and hexagonal boron nitride (h-BN) was carried out. We found that h-BN had a significant nucleation effect on crystallization behaviors. DSC isothermal crystallization results demonstrated that the crystallization time of the PESu/h-BN composites became shorter after adding h-BN. The rate constant k values calculated from the Avrami equation were larger for the composites, demonstrating that PESu’s crystallization rate was increased by adding h-BN. TEM and SEM images showed the well-dispersed h-BN in the PESu matrix. Optical microscopy revealed that the PESu/h-BN composites formed more and smaller spherulites than neat PESu did, which confirmed that h-BN caused the nucleation effect. H-BN also accelerated non-isothermal crystallization kinetics. We discussed the behaviors of the Mo model, which demonstrated that h-BN promoted the kinetics of non-isothermal crystallization. The XRD diffraction patterns showed that h-BN in the composites would not obviously change the crystalline structure of PESu.

Effect of Zeolite as a Green Catalyst and Nucleation Agent on the Physical Properties of Poly(Ethylene 2,5-Furan-Dicarboxylate)

2018 ◽  
Vol 773 ◽  
pp. 88-93
Author(s):  
Je Young Park ◽  
Dong Yeop X. Oh ◽  
Tae Ho Kim ◽  
Sung Yeon Hwang
Keyword(s):  
In Situ Polymerization ◽  
Average Molecular Weight ◽  
Crystallization Rate ◽  
Melt Crystallization ◽  
Nucleation Agent ◽  
Weight Average Molecular Weight ◽  
Green Catalyst ◽  
Highest Weight ◽  
Poly Ethylene

In this study, poly(ethylene 2,5-furan dicarboxylate) (PEF) was synthesized from biomass-based dimethyl furan-2,5-dicarboxylate using different-sized zeolites, with substituted ions such as Li and K, as efficient green catalysts for in situ polymerization. The Z5Ali catalyst yielded the PEF biopolyester with the highest weight-average molecular weight among all the samples: 53,800 g/mol. From their TGA curves, it was confirmed that the PEF sample with ZA5Li as the catalyst showed an increased thermal stability compared to homo-PEF. Generally, homo-PEF exhibited a very low melt-crystallization rate with low enthalpy. However, all the PEF samples using zeolite as the catalyst formed endotherms I and II. This result was attributed to the fact that zeolite affects the melt and recrystallization of imperfect crystals due to physical hindrance.

scholarly journals Effect of Cyanuric Acid as an Efficient Nucleating Agent on the Crystallization of Novel Biodegradable Branched Poly(Ethylene Succinate)

Macromol ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 112-120
Author(s):  
Kangjing Zhang ◽  
Zhaobin Qiu
Keyword(s):  
Cyanuric Acid ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Crystallization Mechanism ◽  
Nucleation Density ◽  
Half Time ◽  
Melt Crystallization ◽  
Casting Method ◽  
Crystallization Peak ◽  
Poly Ethylene

Novel biodegradable branched poly(ethylene succinate) (b-PES) composites, i.e., nucleated b-PES samples, were prepared by incorporating low loadings of cyanuric acid (CA) through a solution and casting method to enhance the crystallization rate. As an efficient nucleating agent, CA could remarkably increase the nonisothermal melt crystallization peak temperature, shorten the crystallization half-time, accelerate the overall isothermal melt crystallization, and enhance the nucleation density of b-PES spherulites in the composites. Despite the addition of CA, the crystallization mechanism and crystal structure of b-PES remained unchanged. A possible epitaxial crystallization mechanism may account for the nucleation of b-PES crystals induced by CA.

Mechanical enhancement and crystallization kinetics of polyoxymethylene-based composite film with carbon nanotube

2015 ◽  
Vol 30 (5) ◽  
pp. 599-607 ◽  
Author(s):  
Peng Chunzheng ◽  
Cai Chilan ◽  
Tian Haobin ◽  
Zhang Jianguo
Keyword(s):  
Carbon Nanotube ◽  
Composite Film ◽  
Interfacial Adhesion ◽  
Crystallization Rate ◽  
Nucleation Density ◽  
Nucleation Agent ◽  
Thermal Stabilities ◽  
The Matrix ◽  
Reinforcing Material ◽  
Kinetics Of

Carbon nanotube (CNT) was employed as a reinforcing material to prepare polyoxymethylene (POM)-based composite film through a simple melting extrusion. An effective approach was developed to clean and modify the surface of as-received CNT with nitric acid and then with a silane coupling agent. The mechanical evaluation demonstrated that a significant reinforcement was achieved for POM/CNT composites due to the improved interfacial adhesion between CNT and the matrix. The thermal stabilities of the composites were also improved in the presence of CNT. The studies on crystallization behaviors showed that CNT acted as a nucleation agent for the crystallization of POM domain in composites, and therefore, the crystallization rate and nucleation density increased remarkably due to the heterogeneous nucleating effect of CNT.

Preparation of poly(L-lactide)/poly(ethylene glycol)/organo-modified montmorillonite nanocomposites via melt intercalation under continuous elongation flow

2018 ◽  
Vol 38 (5) ◽  
pp. 449-460 ◽  
Author(s):  
Ting Wu ◽  
Ding Yuan ◽  
Jin-Ping Qu
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Nucleation Density ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Modified Montmorillonite ◽  
Elongation Flow ◽  
Poly Ethylene

AbstractAn innovative eccentric rotor extruder (ERE), which can generate continuous elongation flow, was used to prepare the poly(L-lactide) (PLLA)/poly(ethylene glycol) (PEG)/organo-modified montmorillonite (OMMT) nanocomposites. The morphology was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and showed that the OMMT nanoparticles were uniformly dispersed in the matrix and mainly existed in intercalation mode. The influence of OMMT on the rheological behavior of plasticized PLLA was investigated by dynamic rheological measurements, showing greater improvement of rheological properties compared to that of PLLA/PEG blend. The crystallization behavior and crystalline structures were studied by differential scanning calorimetry (DSC) and XRD, respectively, and showed that the presence of OMMT further speeds up the crystallization rate of plasticized PLLA. However, the crystallization rate and crystallinity had a slight downward trend at high OMMT content because of the inhibition effect of the OMMT percolation network structure. Polarizing optical microscopy (POM) was further carried out and proved that the OMMT nanoparticles as a heterogeneous nucleating agent can increase the spherulite growth rate and nucleation density. The thermal stability was investigated by thermogravimetric analysis and indicated that the addition of OMMT at low concentration can improve the thermal stability of plasticized PLLA more effectively.

Non-Isothermal Crystallization Behavior of Poly(Ethylene Terephthalate)/Carbon Black Composite

2011 ◽  
Vol 239-242 ◽  
pp. 3198-3206 ◽  
Author(s):  
Zhao Hui Jiang ◽  
Jian Jin ◽  
Chang Fa Xiao ◽  
Xin Li
Keyword(s):  
Crystal Growth ◽  
Carbon Black ◽  
Isothermal Crystallization ◽  
Ethylene Terephthalate ◽  
Crystallization Process ◽  
Crystallization Rate ◽  
Crystal Nucleation ◽  
Avrami Equation ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Poly(Ethylene Terephthalate)(PET)/carbon black(CB) composite was prepared by melt blending using a separate feeding technique. The non-isothermal crystallization process of virgin PET and PET/CB composite were investigated by differential scanning calorimetry (DSC) and the different methods such as Jeziorny modified Avrami equation, Ozawa equation and the method developed by Mo were employed to analyze the non-isothermal kinetics of virgin PET and PET/CB composite. The results show that the CB particles dispersed in PET matrix act as heterogeneous nucleating agents, while CB particles hinder the movement of molecular chains of PET, meanwhile, the crystallization activation energy(⊿E) of PET/CB composite is much greater than that of virgin PET according to Kissinger formula, which is opposite to the low CB content condition. This indicates that CB particles reduce the rate of crystal growth. Whereas, the results obtained from the mentioned three methods simultaneously demonstrate the addition of CB greatly increases crystallization temperature and crystallinity and accelerates crystallization rate. Taking the two seemingly contradictory results, crystal growth has little effect on the crystallization rate and crystal nucleation dominate the crystallization process of PET/CB composite with very high CB content. According to Jeziorny method, the constant of crystallization rate (Zc) increases with the increment of cooling rate and Avrami index (n) doesn’t change significantly, but the Zc and n of PET/CB composite are greater than that of PET. Based on Ozawa method, lg[-ln(1-Xt)] and lgR don’t show a good linear relationship. The parameter F(T) increases significantly with the increasing of relative crystallinity and n is almost unchanged. Besides, the F(T) of PET/CB composite is less than that of PET, while a is greater than that of PET. Comparing with Ozawa and Avrami equation, Mo method can better describe the non-isothermal crystallization of PET and PET/CB composite.

CRYSTALLINE STRUCTURES AND α → β AND γ POLYMORPHS TRANSFORMATION INDUCED BY NANOCLAY IN PVDF-BASED NANOCOMPOSITE

NANO ◽  
2014 ◽  
Vol 09 (06) ◽  
pp. 1450065 ◽  
Author(s):  
MOHAMMAD MAHDI ABOLHASANI ◽  
MINOO NAEBE ◽  
AZAM JALALI-ARANI ◽  
QIPENG GUO
Keyword(s):  
Electron Microscopy ◽  
Isothermal Crystallization ◽  
Vinylidene Fluoride ◽  
Crystallization Rate ◽  
Avrami Exponent ◽  
Degree Of Crystallinity ◽  
Nucleation Agent ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Clay Platelets

Poly(vinylidene fluoride) (PVDF) nanocomposites were prepared by melt-mixing. The dispersion of clay platelets and rheology of nanocomposites were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and rheometric mechanical spectrometer (RMS). The transformation of α to β and γ phase in PVDF was induced by the addition of nanoclay and subsequently the isothermal crystallization kinetics of neat PVDF and its nanocomposite have been investigated. The interaction between clay nanofillers and PVDF macromolecular chains induced the change of conformation from trans-gauche to all-trans crystal structure in PVDF segment. The isothermal crystallization of PVDF/clay nanocomposites was carried out by Differential Scanning Calorimetry (DSC) technique. The influence of clay platelets on nucleation crystallization rate and Avrami exponent were studied. PVDF/clay nanocomposite showed higher crystallization rate indicating that nanoclay has acted as an effective nucleation agent. This nucleation effect of nanoclay increased the Avrami exponent and decreased the degree of crystallinity.

scholarly journals Polyethylenimine Assisted Bio-Inspired Surface Functionalization of Hexagonal Boron Nitride for Enhancing the Crystallization and the Properties of Poly(Arylene Ether Nitrile)

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 760 ◽  
Author(s):  
Yajie Wang ◽  
Lifen Tong ◽  
Yong You ◽  
Ling Tu ◽  
Meirong Zhou ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Boron Nitride ◽  
Surface Functionalization ◽  
Crystallization Behavior ◽  
Hexagonal Boron Nitride ◽  
Nanocomposite Films ◽  
Nucleation Density ◽  
Nucleation Agent ◽  
Scanning Calorimetry ◽  
Arylene Ether

Semi-crystalline poly(arylene ether nitrile) (PEN) has exhibited remarkable potential in various fields. However, the inherent drawbacks of PEN such as slow crystalline rate and low crystallinity limit its further development. To alleviate this problem, the choice of nanofiller as nucleation agent and the interfacial compatibility between nanofiller and PEN matrix are two momentous factors that need to be considered. Accordingly, in this work, functionalized hexagonal boron nitride (h-BN@(PDA+PEI)) was successfully synthesized via polyethylenimine (PEI) assisted bio-inspired surface functionalization, and then homogeneously dispersed in the PEN resin using solution casting method to obtain functional polymer nanocomposite films with strengthening the crystallization behavior, mechanical and dielectric properties. Various testing methods including differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD), and polarizing microscope (POM) were applied to intricately analyze the effect of h-BN@(PDA+PEI) on the crystallization behavior of PEN composites. The testing results certificated that the h-BN@(PDA+PEI) can effectively improve the crystallinity (from 6.56% to 14.90%), and the spherulite size of PEN was reduced while the nucleation density of nanocomposites was raised. Furthermore, the non-isothermal crystallization kinetics demonstrated that 2 wt% h-BN@(PDA+PEI) could significantly reduce the cold crystallization temperature (Tp) and the crystallization activation energy (Ea) (from 359.7 KJ/mol to 292.8 KJ/mol), while it improved the crystallization rate (Kc) of PEN. In addition, the mechanical and dielectric properties of nanocomposite films were also reinforced to further broaden the application of semi-crystalline PEN. Therefore, the h-BN@(PDA+PEI) can function as an effectual nucleating agent and enhance the performance of PEN.

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