scholarly journals Isothermal Crystallization Kinetics and Morphology of Double Crystalline PCL/PBS Blends Mixed with a Polycarbonate/MWCNTs Masterbatch

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 682 ◽  
Author(s):  
Thandi P. Gumede ◽  
Adriaan S. Luyt ◽  
Agnieszka Tercjak ◽  
Alejandro J. Müller
Keyword(s):  
Isothermal Crystallization ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Intimate Contact ◽  
Rich Phase ◽  
Force Microscopy ◽  
Partial Miscibility ◽  
Nucleation Effect ◽  
The Matrix ◽  
Twin Screw

In this work, the 70/30 and 30/70 w/w polycaprolactone (PCL)/polybutylene succinate (PBS) blends and their corresponding PCL/PBS/(polycarbonate (PC)/multiwalled carbon nanotubes (MWCNTs) masterbatch) nanocomposites were prepared in a twin-screw extruder. The nanocomposites contained 1.0 and 4.0 wt% MWCNTs. The blends showed a sea-island morphology typical of immiscible blends. For the nanocomposites, three phases were formed: (i) The matrix (either PCL- or PBS-rich phase depending on the composition), (ii) dispersed polymer droplets of small size (either PCL- or PBS-rich phase depending on the composition), and (iii) dispersed aggregates of tens of micron sizes identified as PC/MWCNTs masterbatch. Atomic force microscopy (AFM) results showed that although most MWCNTs were located in the PC dispersed phase, some of them migrated to the polymer matrix. This is due to the partial miscibility and intimate contact at the interfaces between blend components. Non-isothermal differential scanning calorimetry (DSC) scans for the PCL/PBS blends showed an increase in the crystallization temperature (Tc) of the PCL-rich phase indicating a nucleation effect caused by the PBS-rich phase. For the nanocomposites, there was a decrease in Tc values. This was attributed to a competition between two effects: (1) The partial miscibility of the PC-rich and the PCL-rich and PBS-rich phases, and (2) the nucleation effect of the MWCNTs. The decrease in Tc values indicated that miscibility was the dominating effect. Isothermal crystallization results showed that the nanocomposites crystallized slower than the neat blends and the homopolymers. The introduction of the masterbatch generally increased the thermal conductivity of the blend nanocomposites and affected the mechanical properties.

Thermal and Tensile Properties of PP Nanocomposite Blends

2008 ◽  
Vol 47-50 ◽  
pp. 21-24
Author(s):  
C. Rosales ◽  
V. Contreras ◽  
M. Matos ◽  
R. Perera ◽  
N. Villarreal ◽  
...  
Keyword(s):  
Tensile Modulus ◽  
Polyamide 6 ◽  
Dispersed Phase ◽  
Scanning Calorimetry ◽  
Binary Blend ◽  
Polyethylene Blends ◽  
Metallocene Polyethylene ◽  
The Matrix ◽  
Twin Screw ◽  
Layered Clay

Polypropylene/polyamide-6 and polypropylene/metallocene polyethylene blends containing 2.5 phr of organophilic modified montmorillonite were prepared in a twin-screw extruder followed by injection molding. In order to compare, blends without layered clay were also made. Styreneethylene- butylene-styrene copolymer and polypropylene grafted with anhydride maleic were used as compatibilizers in the ternary blends and in the PP nanocomposite preparation, respectively. The presence of tactoids, intercalated and exfoliated structures was observed by TEM in some of the samples containing layered clay and modified PP materials. Results showed that the compatibilized blends prepared without clay are tougher than those prepared with the nanocomposite of PP as the matrix phase and no significant changes in tensile moduli were observed between them. However, the binary blend with a nanocomposite of PP as matrix and metallocene polyethylene exhibited better tensile toughness and lower tensile modulus, than those prepared with a nanocomposite of PP and polyamide-6 as dispersed phase. These results are related to the degree of clay dispersion in the PP and to the type of morphology developed in the different blends. Differential scanning calorimetry (DSC) showed that blends with a finer and homogeneously dispersed morphology determined by SEM, the PA component exhibited fractionated crystallization exotherms in the temperature range of 159-185°C. Also, nucleation of the PP component by PA phase and/or the layered clay was observed in the blends with PA as dispersed phase.

Structure and Properties of Hybrid Polyurethane Composites with Carboxyalumoxanes

2008 ◽  
Vol 587-588 ◽  
pp. 212-216 ◽  
Author(s):  
Magdalena Jurczyk-Kowalska ◽  
Joanna Ryszkowska
Keyword(s):  
In Situ Polymerization ◽  
Structure And Properties ◽  
Mechanical Mixing ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Matrix ◽  
Polyurethane Composites ◽  
Polyurethane Matrix

Carboxyalumoxanes have been incorporated into a polyurethane matrix by in situ polymerization. The filler was dispersed in the polyurethane matrix by either both ultrasonic and mechanical mixing or by mechanical mixing alone. The physico-mechanical properties of the composites have been characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Using ultrasound improves the degree of dispersion of the fillers in the matrix, but it also causes changes in the structure of the polyurethane matrix.

STRAIN-INDUCED CRYSTALLIZATION AND MECHANICAL PROPERTIES OF NBR COMPOSITES WITH CARBON NANOTUBE AND CARBON BLACK

2012 ◽  
Vol 85 (2) ◽  
pp. 207-218 ◽  
Author(s):  
Sang-Ryeoul Ryu ◽  
Jong-Whan Sung ◽  
Dong-Joo Lee
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Nanotube ◽  
Carbon Black ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Extension Ratio ◽  
The Matrix ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Abstract The mechanical properties and strain-induced crystallization (SIC) of elastomeric composites were investigated as functions of the extension ratio (λ), multiwalled carbon nanotube (CNT) content, and carbon black (CB) content. The tensile strength and modulus gradually increase with increasing CNT content when compared with the matrix and the filled rubbers with same amount of CB. Both properties of rubber with CB and CNT show the magnitude of each CNT and CB component following the Pythagorean Theorem. The ratio of tensile modulus is much higher than that of tensile strength because of the CNT shape/orientation and an imperfect adhesion between CNT and rubber. The tensile strength and modulus of the composite with a CNT content of 9 phr increases up to 31% and 91%, respectively, compared with the matrix. Differential scanning calorimetry (DSC) analysis reveals that the degree of SIC increases with an increase in CNT content. Mechanical properties have a linear relation with the latent heat of crystallization (LHc), depending on the CNT content. As the extension ratio increases, the glass-transition temperature (Tg) of the composite increases for CB- and CNT-reinforced cases. However, the LHc has a maximum of λ = 1.5 for the CNT-reinforced case, which relates to a CNT shape and an imperfect adhesion with rubber. Based on these results, the reinforcing mechanisms of CNT and CB are discussed.

Preparation and Characterization of Multiwalled Carbon Nanotubes-Reinforced pCBT by Ring-Opening Polymerization of Cyclic Butylene Terephthalate

2016 ◽  
Vol 848 ◽  
pp. 125-131
Author(s):  
Yin He Su ◽  
Jun Rong Yu
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Butylene Terephthalate ◽  
Cyclic Butylene Terephthalate ◽  
The Matrix ◽  
Higher Temperature

Multiwalled carbon nanotubes (MWCNT)-reinforced polymerized cyclic butylene terephthalate (pCBT) nanocomposites were prepared by in situ ring opening polymerization of cyclic butylene terephthalate oligomers (CBT). The results of differential scanning calorimetry (DSC) indicated that the melting peak located at the low temperature (Tm1) increased and that at higher temperature (Tm2) decreased with the increasing of content of the MWCNT. During the cooling the MWCNT served as nucleation points from where crystallization can start. The more the MWCNT in the system the earlier the crystallization starts. The Morphological investigations performed by scanning electron microscopy (SEM) shown that the MWCNT were embedded in the matrix and held tightly by the matrix. The modulus and strength increased with MWCNT concentration in the nanocomposites, however, the elongation at break, absorbed energy at break and impact strength were decreased with the increasing of MWCNT content.

Isothermal Crystallization Behavior and Kinetics of Poly (lactic acid) Filled with a Novel Nucleating Agent

2014 ◽  
Vol 887-888 ◽  
pp. 716-722
Author(s):  
Nai Xu ◽  
Xing Hui Wang ◽  
Li Sha Pan ◽  
Su Juan Pang ◽  
Xuan Chen ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Nucleating Agent ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Nucleation Effect ◽  
Amide Derivatives ◽  
Aromatic Amide ◽  
Kinetics Of

The crystallization behavior and crystalline structure of poly (lactic acid) (PLA) filled with a novel nucleating agent (TMC328), which is a kind of aromatic amide derivatives, were investigated using differential scanning calorimetry (DSC) and wide angle X-ray (XRD). In isothermal crystallization from the melt, the present of TMC328 remarkably affected the isothermal crystalline behaviors of PLA. PLA/0.5% TMC328 sample exhibited very short crystallization half-times at 90-130 °C. Furthermore, the Avrami theory was used to describe the isothermal crystallization kinetics of PLA/TMC328 samples. It is confirmed that TMC328 showed a significant heterogeneous nucleation effect on the crystallization of PLA matrix. Moreover, XRD measurement indicates that TMC328 is a kind of α-form nucleating agent for PLA.

scholarly journals Maleated polypropylene as coupling agent for polypropylene composites reinforced with Eucalyptus and Pinus particles

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 4774-4791
Keyword(s):  
Degree Of Crystallinity ◽  
Esterification Reaction ◽  
Scanning Electron Micrographs ◽  
Scanning Calorimetry ◽  
Polypropylene Composites ◽  
Maleated Polypropylene ◽  
The Matrix ◽  
Twin Screw ◽  
Coniferous Wood ◽  
Scanning Electron

Waste from the processing of hardwood and coniferous wood generated in the timber industries is difficult to dispose of and can cause considerable environmental impacts, such as soil and groundwater contamination. In this context, composites with varying concentrations of polypropylene, maleated polypropylene, and particulate Eucalyptus and Pinus waste were produced in a twin screw extruder and injection molded as test bodies for tensile and flexural tests. The morphology of the composites was investigated via scanning electron microscopy. The thermal properties were identified through differential scanning calorimetry. The tensile and flexural results for the two waste formulations indicated that the addition of vegetable fillers increased the modulus of elasticity and bending, and the compatibilizer provided increased resistance to stress and maximum deflection. The scanning electron micrographs illustrated the wetting of the cellulosic charge by the thermoplastic polymer with the compatibilizer, which corroborated the possible occurrence of an esterification reaction and hydrogen bonding interactions in the matrix-particle interface. The incorporation of waste in the composite resulted in the reduction of the degree of crystallinity of polypropylene, regardless of the use of the compatibilizer. This was explained by the barrier capacity of the charge, which prevented the growth of the crystals.

scholarly journals Controlling the Isothermal Crystallization of Isodimorphic PBS-ran-PCL Random Copolymers by Varying Composition and Supercooling

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 17 ◽  
Author(s):  
Maryam Safari ◽  
Agurtzane Mugica ◽  
Manuela Zubitur ◽  
Antxon Martínez de Ilarduya ◽  
Sebastián Muñoz-Guerra ◽  
...  
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Polarized Light ◽  
Eutectic Point ◽  
Random Copolymers ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Butylene Succinate ◽  
Rich Phase ◽  
Spherulitic Growth

In this work, we study for the first time, the isothermal crystallization behavior of isodimorphic random poly(butylene succinate)-ran-poly(ε-caprolactone) copolyesters, PBS-ran-PCL, previously synthesized by us. We perform nucleation and spherulitic growth kinetics by polarized light optical microscopy (PLOM) and overall isothermal crystallization kinetics by differential scanning calorimetry (DSC). Selected samples were also studied by real-time wide angle X-ray diffraction (WAXS). Under isothermal conditions, only the PBS-rich phase or the PCL-rich phase could crystallize as long as the composition was away from the pseudo-eutectic point. In comparison with the parent homopolymers, as comonomer content increased, both PBS-rich and PCL-rich phases nucleated much faster, but their spherulitic growth rates were much slower. Therefore, the overall crystallization kinetics was a strong function of composition and supercooling. The only copolymer with the eutectic composition exhibited a remarkable behavior. By tuning the crystallization temperature, this copolyester could form either a single crystalline phase or both phases, with remarkably different thermal properties.

scholarly journals Effect of Filler Dimensionality on Mechanical Properties of Nanofiller Reinforced Polyolefin Elastomers

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Sharmila Pradhan ◽  
Ralf Lach ◽  
Hong Hai Le ◽  
Wolfgang Grellmann ◽  
Hans-Joachim Radusch ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Nanocomposites ◽  
Tensile Testing ◽  
Layered Silicate ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Reinforcing Effect ◽  
Microindentation Hardness ◽  
The Matrix ◽  
Morphology And Mechanical Properties

The object of this study has been to investigate the effect of filler dimensionality on morphology and mechanical properties of polymer nanocomposites using various kinds of nanofillers (such as multiwalled carbon nanotubes (1D filler), layered silicate (2D filler), and boehmite (3D filler)) dispersed in the matrix of ethylene-1-octene copolymer (EOC), a polyolefin-based elastomer. The morphological features were studied by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) while mechanical properties were characterized by tensile testing and depth sensitive recording microindentation hardness measurements. It has been demonstrated that the filler dimensionality may have dramatic influence on the mechanical properties of the samples. Based on the results obtained by tensile testing and microhardness measurements, the reinforcing effect of the nanofiller was found to follow the order: 1D filler > 2D filler > 3D filler.

INVESTIGATION ON THE MORPHOLOGICAL AND THERMAL PROPERTIES OF POLYLACTIC ACID/POLYCAPROLACTONE LOADED WITH HALLOYSITE NANOTUBES AND BASALT FIBER

2022 ◽  
Author(s):  
A. ARUL JEYA KUMAR ◽  
NIRANJAN S. RAJ ◽  
C. SAIPRASAD ◽  
AGHALAYAM R. SUDHANVA
Keyword(s):  
Thermal Properties ◽  
Polylactic Acid ◽  
Basalt Fiber ◽  
Halloysite Nanotubes ◽  
Morphological Characterization ◽  
Degree Of Crystallinity ◽  
Thermal Testing ◽  
Scanning Calorimetry ◽  
The Matrix ◽  
Twin Screw

This paper is focused on the analysis of the morphological and thermal properties of the biomedical composites, polylactic acid (PLA) and polycaprolactone (PCL) matrix, reinforced with basalt fibers (BFs) and using halloysite nanotubes (HNT) as filler material. Four different composites, viz. PPHB 1, PPHB 2, PPHB 3 and PPHB 4, are obtained by varying the weight fractions of these materials using twin-screw extrusion followed by injection molding. The morphological characterization is performed on these composites using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. SEM reveals homogenous and strong bonding between the matrix, reinforcement and filler. The BF are well embedded in the matrix with a random orientation. No formation of voids and cracks is observed. The functional groups present and the types of vibration experienced by the chemical bonds were observed in the FTIR spectra. The composites are subjected to thermal testing such as differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The PPHB 2, which contains 80% PLA, 10% BF, 7% PCL and 3% HNT, has the highest degree of crystallinity, as revealed by DSC, and exhibits the most optimum thermal degradation characteristics as indicated by TGA.

Non-Isothermal Crystallization Kinetics and Melting Behaviors of Thermoplastic/Liquid Crystalline Polymer Blends of Poly(Trimethylene Terephthalate)/Vectra A950

2008 ◽  
Vol 54 ◽  
pp. 249-254 ◽  
Author(s):  
Penwisa Pisitsak ◽  
Rathanawan Magaraphan
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
Nucleation Effect ◽  
Trimethylene Terephthalate ◽  
Kinetics Of

The non-isothermal crystallization and subsequent melting behaviors of poly(trimethylene terephthalate), (PTT)/Vectra A950, (VA) blends with different VA contents were studied by differential scanning calorimetry. The effects of VA on the non-isothermal crystallization kinetics of PTT were discussed based on the Ozawa model. It was found that VA has a nucleation effect on PTT crystallization. The triple melting endotherms were found in the subsequent melting thermograms. The blends are clearly immiscible as verified by the unchanged Tg and morphological results.

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