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.

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 Monte Carlo Simulation for the Morphology and Kinetics of Spherulites and Shish-Kebabs in Isothermal Polymer Crystallization

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Chunlei Ruan ◽  
Chuntai Liu ◽  
Guoqiang Zheng
Keyword(s):  
Growth Rate ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Crystallization Rate ◽  
Polymer Crystallization ◽  
Nucleation Density ◽  
Length Growth ◽  
Average Size ◽  
Kinetics Of

Monte Carlo method is used to capture the evolution of spherulites and shish-kebabs and to predict the crystallization kinetics in isothermal polymer crystallization. Effects of nucleation density and growth rate of spherulites, nucleation density, and length growth rate of shish-kebabs, respectively, on crystallization are investigated. Results show that nucleation densities of both spherulites and shish-kebabs strongly affect crystallization rate as well as morphology. An increase in nucleation density of either spherulites or shish-kebabs leads to a quicker crystallization rate and a smaller average spherulite size. It is also shown that nucleation density of shish-kebabs has a stronger impact on crystallization rate. Growth rate of spherulites and length growth rate of shish-kebabs also have significant effect on crystallization rate and morphology. An increase in growth rate of spherulites or length growth rate of shish-kebabs also speeds up the crystallization rate; additionally, a decrease in growth rate of spherulites or an increase in length growth rate of shish-kebabs results in a more highly anisotropic shish-kebab structure and a smaller average size of spherulites. Results also show that the effect of growth rate of spherulites is more important than the effect of length growth rate of shish-kebabs on crystallization.

scholarly journals Nonisothermal Crystallization Kinetics of Acetylated Bamboo Fiber-Reinforced Polypropylene Composites

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1078 ◽  
Author(s):  
Yu-Shan Jhu ◽  
Teng-Chun Yang ◽  
Ke-Chang Hung ◽  
Jin-Wei Xu ◽  
Tung-Lin Wu ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Crystallization Kinetics ◽  
Crystallization Rate ◽  
Bamboo Fiber ◽  
Crystallization Time ◽  
Nucleation Agent ◽  
Relative Crystallinity ◽  
Crystallinity Degree ◽  
Friedman Method ◽  
Kinetics Of

The crystallization behavior of bamboo fiber (BF) reinforced polypropylene (PP) composites (BPCs) was investigated using a differential scanning calorimeter (DSC). The results showed that unmodified BF as a nucleation agent accelerated the crystallization rate of the PP matrix during cooling whereas there is no significant effect on the improved crystallization rate in BPCs with acetylated BFs. Based on the Avrami method, Avrami–Ozawa method, and Friedman method, the corresponding crystallization kinetics of PP reinforced with different acetylation levels of BFs were further analyzed. The results demonstrated that the crystal growth mechanism of the PP matrix for BPCs with unmodified and various acetylated BFs exhibited tabular crystal growth with heterogeneous nucleation. A higher cooling rate is required to achieve a certain relative crystallinity degree at the unit crystallization time for BPCs with a higher weight percent gain (WPG) of acetylated BFs (WPG >13%). Furthermore, based on the Friedman method, the lowest crystallization activation energy was observed for the BPCs with 19% WPG of acetylated BFs.

Preparation and Characterization of Polyurethane/Multiwalled Carbon Nanotube Composites

2008 ◽  
Vol 16 (8) ◽  
pp. 501-507 ◽  
Author(s):  
Shuzhong Guo ◽  
Chao Zhang ◽  
Weizhi Wang ◽  
Tianxi Liu ◽  
Wuiwui Chauhari Tjiu ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Interfacial Adhesion ◽  
In Situ Polymerization ◽  
Stress Transfer ◽  
Mechanical Analysis ◽  
Mechanical Tests ◽  
Multiwalled Carbon Nanotube ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
Nanotube Composites

Multiwalled carbon nanotube (MWNT)/polyurethane (PU) nanocomposites have been prepared by the combination of in-situ polymerization and solution-casting approach. A homogeneous dispersion of MWNTs throughout PU matrix is observed by scanning electron microscopy on the fracture surfaces of the composites. Strong interfacial adhesion between the MWNTs and the PU matrix, as evidenced by the presence of broken but strongly embedded MWNTs in the matrix, is favorable to stress transfer from polymer matrix to the nanotubes. Mechanical tests (by tensile testing and dynamic mechanical analysis) show that, compared with neat PU, both the Young's modulus and the tensile strength of the composites are significantly improved by about 90%, with incorporating only 1 wt.% MWNTs. And most importantly, the elongation-at-break of PU/carbon nanotube (CNT) composites is greatly improved by about 500%, indicating that the toughness of neat PU is remarkably enhanced by adding CNTs into the matrix. The fine dispersion of CNTs and strong interfacial adhesion between the CNTs with the matrix are responsible for the simultaneous and significant enhancement in the strengthening and toughening of PU matrix. In addition, the thermal stability of PU was also improved after incorporating CNTs into the matrix.

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 Fabrication and Microhardness Analysis of MWCNT/MnO2 Nanocomposite

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Md. Zakir Hussain ◽  
Sabah Khan ◽  
Rajamani Nagarajan ◽  
Urfi Khan ◽  
Vishnu Vats
Keyword(s):  
Carbon Nanotube ◽  
Mass Density ◽  
Weight Fraction ◽  
Xrd Analysis ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Weight Percentage ◽  
The Matrix ◽  
Reinforcing Material ◽  
Nanocomposite Powders

Recent research has shown that carbon nanotube (CNT) acts as a model reinforcement material for fabricating nanocomposites. The addition of CNT as a reinforcing material into the matrix improves the mechanical, thermal, tribological, and electrical properties. In this research paper multiwalled carbon nanotube (MWCNT), with different weight percentage (5%, 10%, and 15%), was reinforced into manganese dioxide (MnO2) matrix using solution method. The different weight % of MWCNT/MnO2 nanocomposite powders was compacted and then sintered. The phase analysis, morphology, and chemical composition of the nanocomposites were examined by X-ray diffractometer, Field Emission Scanning Electron Microscope (FESEM), and Energy Dispersive X-Ray (EDX), respectively. The XRD analysis indicates the formation of MWCNT/MnO2 nanocomposites. The FESEM surface morphology analysis shows that MnO2 nanotube is densely grown on the surface of MWCNT. Further, microhardness of MWCNT/MnO2 nanocomposite was measured and it was found that 10 wt% has higher microhardness in comparison to 5 and 15 wt%. The microhardness of the composites is influenced by mass density, nanotube weight fraction, arrangement of tubes, and dispersion of MWCNT in H2SO4(aq) solution.

scholarly journals Coefficient of Thermal Expansion of Single-Wall Carbon Nanotube Reinforced Nanocomposites

2021 ◽  
Vol 5 (1) ◽  
pp. 26
Author(s):  
Chensong Dong
Keyword(s):  
Experimental Data ◽  
Thermal Expansion ◽  
Carbon Nanotube ◽  
Interfacial Adhesion ◽  
Coefficient Of Thermal Expansion ◽  
Single Wall Carbon Nanotube ◽  
Single Wall Carbon ◽  
The Matrix ◽  
Adhesion Factor ◽  
Good Agreement

A study on the coefficient of thermal expansion (CTE) of single-wall carbon nanotube (SWCNT)-reinforced nanocomposites is presented in this paper. An interfacial adhesion factor (IAF) is introduced for the purpose of modelling the adhesion between SWCNTs and the matrix. The effective CTE and modulus of SWCNTs are derived using the IAF, and the effective CTE of the nanocomposite is derived by the Mori–Tanaka method. The developed model is validated against experimental data and good agreement is found.

scholarly journals Effect of Carbon Nanotube Addition on the Interfacial Adhesion between Graphene and Epoxy: A Molecular Dynamics Simulation

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 121 ◽  
Author(s):  
Shuangqing Sun ◽  
Shenghui Chen ◽  
Xuanzhou Weng ◽  
Fei Shan ◽  
Songqing Hu
Keyword(s):  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Graphene Sheet ◽  
Interfacial Adhesion ◽  
Axial Direction ◽  
Equilibrium Structure ◽  
Dynamics Simulation ◽  
Graphene Composite ◽  
The Matrix ◽  
Dynamics Simulations

The pullout process of graphene from an epoxy/graphene composite filled with a carbon nanotube (CNT) was simulated by molecular dynamics simulations. The interaction energy and the interfacial adhesion energy were calculated to analyze the effect of CNT addition on the interfacial adhesion between the graphene and the epoxy matrix, with varying CNT radii, distances between the CNT and the graphene sheet, CNT axial directions, and the number of CNT walls. Generally, the addition of a CNT strengthens the interfacial adhesion between the graphene and the polymer matrix. Firstly, a larger CNT radius induces a stronger interfacial adhesion of graphene with the matrix. Secondly, when the CNT is farther away from the graphene sheet, the interfacial adhesion of graphene with the matrix becomes weaker. Thirdly, the CNT axial direction has little effect on the interfacial adhesion of graphene in the equilibrium structure. However, it plays an important role in the graphene pullout process. Finally, compared with a single-walled CNT, the interfacial adhesion between graphene and the matrix is stronger when a double-walled CNT is added to the matrix.

scholarly journals New Insights into Crystallization of Heterophasic Isotactic Polypropylene by Fast Scanning Chip Calorimetry

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1683
Author(s):  
Daniela Mileva ◽  
Jingbo Wang ◽  
Markus Gahleitner ◽  
Katalee Jariyavidyanont ◽  
René Androsch
Keyword(s):  
Crystallization Kinetics ◽  
Isotactic Polypropylene ◽  
Crystallization Rate ◽  
Crystal Nucleation ◽  
Crystallization Time ◽  
Chip Calorimetry ◽  
The Matrix ◽  
Homogeneous Crystal ◽  
Kinetics Of ◽  
Fast Scanning Chip Calorimetry

The crystallization kinetics of metallocene-catalyzed heterophasic isotactic polypropylene composed of a matrix of isotactic polypropylene (iPP) and rubbery particles made of random ethylene–propylene copolymers (EPC), often denoted as heterophasic iPP copolymers, was analyzed as a function of the cooling rate and supercooling in nonisothermal and isothermal crystallization experiments, respectively. Fast scanning chip calorimetry (FSC) allowed assessing crystallization at processing-relevant conditions, and variation of the content (0–39 wt %) and composition (0–35 wt % propylene counits) of the EPC particles revealed qualitatively new insight about mechanisms of heterogeneous crystal nucleation. For neat iPP homopolymer, the characteristic bimodal temperature dependence of the crystallization rate due to predominance of heterogeneous and homogeneous crystal nucleation at high and low temperatures, respectively, is reconfirmed. At high temperatures, in heterophasic iPP, the here studied ethylene-(C2)-rich EPC particles accelerate crystallization of the iPP-matrix, with the acceleration or nucleation efficacy correlating with the EPC-particle content. The crystallization time reduces by more than half in presence of 39 wt % EPC particles. An additional nucleating effect of the EPC particles on iPP-matrix crystallization is detected after their crystallization, suggesting that liquid/rubbery particles are less effective than solid/semicrystalline particles in affecting crystallization of the surrounding iPP-matrix. At low temperature, homogeneous crystal nucleation in the iPP-matrix outpaces all heterogeneous nucleation effects, and the matrix-crystallization rate is independent of the sample composition. The obtained results lead to the conclusion that the crystallization kinetics of iPP can be affected significantly by the content and composition of EPC particles, even towards superfast crystallizing iPP grades.

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