scholarly journals Flow Characteristics, Mechanical, Thermal, and Thermomechanical Properties, and 3D Printability of Biodegradable Polylactide Containing Boehmite at Different Loadings

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2019
Author(s):  
Dimakatso Makwakwa ◽  
Vincent Ojijo ◽  
Jayita Bandyopadhyay ◽  
Suprakas Sinha Ray
Keyword(s):  
Flow Characteristics ◽  
Thermomechanical Properties ◽  
Chain Extender ◽  
Screw Extruder ◽  
Reinforcing Effect ◽  
Transmission Electron ◽  
Heat Distortion Temperature ◽  
Twin Screw ◽  
Enhanced Properties ◽  
A Chain

This work investigates the effects of modification of polylactide (PLA) using dicumyl peroxide (DCP) as a crosslinker and Joncryl as a chain extender on boehmite distribution. The PLA/boehmite (PLA/BA) composites at various concentrations were prepared via a twin-screw extruder. Transmission electron microscopy showed more agglomerations of BA particles when Joncryl and DCP were added individually to the PLA matrix, with lesser agglomeration upon simultaneous addition of DCP and Joncryl, which led to an enhancement of 10.7% of the heat distortion temperature and 8.8% of the modulus. The existence of fine dispersed BA particles in the BA3 sample improved the cold crystallization by 4 °C. Moreover, the maximum reinforcing effect in increasing the storage modulus of the prepared system was observed upon concurrent addition of DCP and Joncryl, with minimum reinforcing effect upon individual addition of DCP and Joncryl. In general, a bio-based PLA composite base BA with enhanced properties was successfully prepared for various applications.

scholarly journals Viscosity improvement of recycled poly (ethylene terephthalate) from waste bottles by adding antioxidants and chain-extender

2021 ◽  
Vol 302 ◽  
pp. 02019
Author(s):  
Isarankura Na Ayutthaya Siriorn ◽  
Bunyarak Munchumart ◽  
Boondeacha Natanicha ◽  
Sangrawee Nut ◽  
Markmee Nopparat ◽  
...  
Keyword(s):  
Shear Viscosity ◽  
Ethylene Terephthalate ◽  
Research Work ◽  
Chain Extender ◽  
Screw Extruder ◽  
Reactive Polymer ◽  
Poly Ethylene Terephthalate ◽  
Twin Screw ◽  
Poly Ethylene ◽  
A Chain

This research work is focused on the viscosity improvement of recycled poly(ethylene terephthalate) (rPET) from waste bottles by adding antioxidants and multi-functional reactive polymer (Joncry ADR 4468, chain extender). The achieve the objective of this work the investigated was broken into two parts. The first part studied the effect of rPET viscosity after adding various types of antioxidants and stabilizer such as Irgafos®168, Tinuvin® 770, Irganox®1010. The second part observed the effect of viscosity after it was blended with chain extender at 0, 0.2, 0.4, 0.6 and 0.8 pph. rPET was then dried in the oven at 120 oC for 12 hrs, to deplete the moisture. Then, the dried rPET (mixed with the chemicals above) was extruded into a compound using a twin screw extruder. The shear viscosity of the extruded compound was then measured using a rotational rheometer at 270 oC. The results revealed that the addition of chain extender increased the shear viscosity and the tensile strength at break of rPET. Therefore, the chain extender interacted with chains, which could change the structure to be the longer chains, branching or network structures. These structures are entangled and interrupt the movement of the molecular chains. It can be concluded that the viscosity of rPET can be improved by adding a chain extender at 0.6 pph, and the antioxidants of Irgafos®168, Tinuvin®770 and Irganox®1010 at 0.2, 0.1 and 0.5 pph, respectively.

Determination of the phase structure of polymerblends by electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 492-493
Author(s):  
Dr. G. Kaemof
Keyword(s):  
Screw Extruder ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Single Screw Extruder ◽  
Transmission Electron ◽  
The Matrix ◽  
Twin Screw ◽  
Special Case ◽  
Microscopic Investigations

A mixture of polycarbonate (PC) and styrene-acrylonitrile-copolymer (SAN) represents a very good example for the efficiency of electron microscopic investigations concerning the determination of optimum production procedures for high grade product properties.The following parameters have been varied:components of charge (PC : SAN 50 : 50, 60 : 40, 70 : 30), kind of compounding machine (single screw extruder, twin screw extruder, discontinuous kneader), mass-temperature (lowest and highest possible temperature).The transmission electron microscopic investigations (TEM) were carried out on ultra thin sections, the PC-phase of which was selectively etched by triethylamine.The phase transition (matrix to disperse phase) does not occur - as might be expected - at a PC to SAN ratio of 50 : 50, but at a ratio of 65 : 35. Our results show that the matrix is preferably formed by the components with the lower melting viscosity (in this special case SAN), even at concentrations of less than 50 %.

scholarly journals Correlation between Structure and Dielectric Breakdown in LDPE/HDPE/Clay Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
B. Zazoum ◽  
E. David ◽  
A. D. Ngô
Keyword(s):  
High Density Polyethylene ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Thermomechanical Properties ◽  
Clay Nanocomposites ◽  
Screw Extruder ◽  
Short Term ◽  
Polyethylene Blend ◽  
Twin Screw ◽  
High Voltage Insulation

Cross-linked polyethylene (XLPE) is commonly used in medium/high voltage insulation due to its excellent dielectric properties and acceptable thermomechanical properties. To improve both electrical and thermal properties to a point that would possibly avoid the need for crosslinking, nanoclay fillers can be added to polymer matrix to form nanocomposites materials. In this paper, PE/clay nanocomposites were processed by mixing a commercially available premixed polyethylene/O-MMT masterbatch into a polyethylene blend matrix containing 80 wt% low density polyethylene LDPE and 20 wt% high density polyethylene HDPE with and without compatibilizer using a corotating twin-screw extruder. Various characterization techniques were employed in this paper, including optical microscopy, AFM, TEM, TGA, DMTA, and dielectric breakdown measurements in order to understand the correlation between structure and short-term dielectric breakdown strength.

The Reinforcement of Acicular Wollastonite on Polypropylene

2010 ◽  
Vol 92 ◽  
pp. 283-288 ◽  
Author(s):  
Ming Shan Yang
Keyword(s):  
Electron Microscope ◽  
Interfacial Adhesion ◽  
Screw Extruder ◽  
Feeding Method ◽  
Reinforcing Effect ◽  
Comprehensive Properties ◽  
Different Types ◽  
Twin Screw ◽  
Pp Composites ◽  
Scanning Electron

The wollastonite/PP composites were manufactured by twin-screw extruder and the effects of compatabilizer, feeding method and screw configuration on the properties of wollastonite/PP composites were investigated in this paper. The dispersion of fibrous wollastonite in PP matrix was determined by scanning electron microscope (SEM). The results showed that the strength, toughness and flowability of the composite were simultaneously guaranteed by using three different types of PP resins, and the interfacial adhesion was improved greatly by adding the compatabilizer of PP-g-MAH, which increases the comprehensive properties of wollastonite/PP composite. The fibrous dispersion of wollastonite in PP matrix was achieved by using of side feeding and the weak-shear screw configuration, which reaches the good reinforcing effect.

Preparation and Chracterization of Nanocomposites of Polyamide 6/Brazilian Clay with Different Organic Modifiers

2008 ◽  
Vol 570 ◽  
pp. 18-23 ◽  
Author(s):  
Michelle A. Souza ◽  
Nelson M. Larocca ◽  
Edcleide Maria Araújo ◽  
Luiz Antonio Pessan
Keyword(s):  
Bentonite Clay ◽  
Polyamide 6 ◽  
X Rays ◽  
Organic Modifiers ◽  
Screw Extruder ◽  
Organic Salts ◽  
Transmission Electron ◽  
Twin Screw ◽  
Izod Impact ◽  
Injection Molded

Nanocomposites of PA6 / organoclay at different concentration were prepared via melt intercalation method using a corotating twin screw extruder. The composites were prepared with Brazilian clay that was treated with different modifiers based on quaternary ammonium salts to obtain three types of organoclays. After extrusion the mixtures were injection molded into specimens that were tested to obtain the properties of tensile strength, notched izod impact and heat deflection temperature. The structure and morphology of the nanocomposites were characterized by x-rays diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the modifier “dodigen” which promoted the intermediate expansion of the bentonite clay within the three salts used for the modification of the clay affects more significantly the mechanical properties, HDT and morphology of the polyamide 6 due to the higher level of exfoliation observed in these systems compared to the others modifiers. The improvement of the properties was correlated to the level of exfoliation/intercalation obtained which depends on the process technique used, surface treatment of the Brazilian clays with organic salts and interaction between polymer and clay.

Structure–properties relationship of the polyurethanes that contain Schiff base in the main chain

2020 ◽  
Vol 32 (7) ◽  
pp. 784-792
Author(s):  
Stefan Oprea ◽  
Violeta Otilia Potolinca ◽  
Veronica Oprea ◽  
Livia Ingrid Diaconu
Keyword(s):  
Schiff Base ◽  
Main Chain ◽  
Raw Materials ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Chain Extender ◽  
Cross Linking ◽  
Practical Applications ◽  
Molar Ratios ◽  
A Chain

This article studies the diversification of useful properties of polyurethane (PU) structures by the inclusion of new components. PUs containing a Schiff base in the main chain were synthesized by using N, N′-bis(salicylidene)-1,3-propanediamine as a chain extender. Novel Schiff base PUs were synthesized via a two-step polymerization starting from a Schiff base derivative diol chain extender with different molar ratios or by cross-linking with various natural raw materials. The sought after structures was confirmed by Fourier transform infrared spectra that showed the disappearance of the signals of both the hydroxyl and isocyanate groups. The thermal properties of these PUs were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The initial degradation temperatures of the obtained PUs were found to be in the range of 300–350°C. Based on the results from DMA, the rigid structure of the Schiff base from the backbone of the PUs presented a higher storage modulus, results which may be connected to the physical cross-linking process of the macromolecules. Their optical properties were determined by fluorescence spectroscopy. The incorporation of Schiff base structures into the main PU chain generates new PU structures with improved thermomechanical properties, which includes possible bioactive Schiff base moieties, widening the range of practical applications for such polymers.

scholarly journals Properties of Styrene–Maleic Anhydride Copolymer Compatibilized Polyamide 66/Poly (Phenylene Ether) Blends: Effect of Maleic Anhydride Concentration and Copolymer Content

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1237 ◽  
Author(s):  
Alper Aksit ◽  
Teresa Menzel ◽  
Merve Aksit ◽  
Volker Altstädt
Keyword(s):  
Electron Microscopy ◽  
Maleic Anhydride ◽  
Thermomechanical Properties ◽  
Cohesive Failure ◽  
Polyamide 66 ◽  
Interfacial Activity ◽  
Transmission Electron ◽  
Twin Screw ◽  
Styrene Maleic Anhydride ◽  
Maleic Anhydride Copolymer

Polyamide 66 (PA66)/poly (2,6-dimethyl-1,4-phenylene ether) (PPE) blends with a ratio of 50/50 (w/w) were produced by a twin-screw compounder. The immiscible blends were compatibilized using two different styrene–maleic anhydride copolymers (SMA) with a low (SMAlow) and a high (SMAhigh) maleic anhydride (MA) concentration of 8 and 25 wt%, respectively. Furthermore, the SMA content was varied from 0 to 10 wt%. The influence of MA concentration and SMA content on the morphological and thermomechanical properties of PA66/PPE blends was investigated. Herein, we established correlations between the interfacial activity of the SMA with blend morphology and corresponding tensile properties. A droplet-sea to co-continuous morphology transition was shown by scanning electron microscopy to occur between 1.25 and 5 wt% in the case of SMAhigh. For SMAlow, the transition started from 7.5 wt% and was still ongoing at 10 wt%. It was found that SMAlow with 10 wt% content enhanced the tensile strength (10%) and elongation at break (70%) of PA66/PPE blends. This improvement can be explained by the strong interfacial interaction of SMAlow within the blend system, which features the formation of nanoemulsion morphology, as shown by transmission electron microscopy. Very small interdomain distances hinder matrix deformations, which forces debonding and cohesive failure of the PPE phase as a “weaker” main deformation mechanism. Due to a lack of interfacial activity, the mechanical properties of the blends with SMAhigh were not improved.

Use of Brazilian Clay in Nylon 6 with Different Molecular Weight Nanocomposites

2010 ◽  
Vol 660-661 ◽  
pp. 777-783
Author(s):  
Edcleide Maria Araújo ◽  
Renê Anísio da Paz ◽  
Tomás Jefférson Alves de Mélo ◽  
Amanda Melissa Damião Leite ◽  
Renata Barbosa ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nylon 6 ◽  
Layered Silicates ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
X Ray ◽  
Torque Rheometry ◽  
Transmission Electron ◽  
Twin Screw ◽  
Different Molecular Weight

The effect of nylon 6 (Ny6) molecular weight on the development of polymer/layered silicates nanocomposites prepared by the melt intercalation technique was studied in this work. The nylon6/organoclay nanocomposites were prepared in the counter-rotational twin screw extruder. The results of torque rheometry showed that the presence of organoclay in the nylon 6 increased the torque. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed exfoliated and/or partially exfoliated structures.

Heat distortion temperature of PPS/PC blend, PPS/PC nanocomposite and PPS/PC/GF hybrid nanocomposite

2013 ◽  
Vol 33 (6) ◽  
pp. 483-488 ◽  
Author(s):  
Ji-Zhao Liang
Keyword(s):  
Calcium Carbonate ◽  
Hybrid Composites ◽  
Particle Surface ◽  
Weight Fraction ◽  
Polyphenylene Sulfide ◽  
Hybrid Nanocomposite ◽  
Screw Extruder ◽  
Ternary Composite ◽  
Heat Distortion Temperature ◽  
Twin Screw

Abstract The polyphenylene sulfide (PPS) blended with polycarbonate (PC), reinforced glass fiber (GF) and nanometer calcium carbonate (nano-CaCO3) filled PPS ternary composite, as well as the PPS/PC/GF/nano-CaCO3 hybrid composite, were prepared by means of a twin-screw extruder, and the heat distortion temperature (Td) of these materials was measured to identify the influence of the PC and nano-CaCO3 content on the heatproof properties. The Td values for the PPS/PC blend were lower than that of the neat PPS, when the PC weight fraction (φPC) was less than 20%, and increased with increase in φPC. The Td values for the PPS/GF/nano-CaCO3 ternary composite, on which the particle surface was treated with a titanate coupler, were higher than that of the composite with the particle surface treated with a stearate coupler. When the nano-CaCO3 weight fraction (φf) was less than 6%, the Td values for the PPS/PC/GF/nano-CaCO3 hybrid composites increased with increasing φf; at greater than the maximum of 6%, Td decreased. There was a certain synergistic effect of the GF and nano-CaCO3 on the heatproof properties in the PPS/PC composite.

Study on the Preparation, Structure and Performances of Antibacterial PET Masterbatch

2011 ◽  
Vol 311-313 ◽  
pp. 131-134 ◽  
Author(s):  
Wen Sheng Hou ◽  
Mei Niu ◽  
Jin Ming Dai ◽  
Sheng Shi ◽  
Zi Lu Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Agent ◽  
Adsorption Process ◽  
Average Diameter ◽  
Coulomb Force ◽  
Functional Material ◽  
Screw Extruder ◽  
E Coli ◽  
Transmission Electron ◽  
Twin Screw

The antibacterial PET (polyethylene terephthalate) masterbatch was extruded from twin screw extruder, using silver and zinc-loading Nano-SiO2 antibacterial agent (SLSZ) as the functional material. The content of SLSZ and extruding techniques were investigated. The dispersion and compatibility of antibacterial agent in antibacterial PET masterbatch were further characterized using Scanning Electron Microscopy and Transmission Electron Microscopy. The antibacterial performances and adsorption process of the antibacterial PET masterbatch against Escherichia coli (E. coli) were tested using alive-bacteria-counting method. The experimental results indicate that when the content of SLSZ was 30 wt. %, the antibacterial agent with an average diameter of 150nm showed excellent dispersion and compatibility in antibacterial PET masterbatch, and had excellent antibacterial performances. The adsorption process of antibacterial PET masterbatch against E. coli was controlled by Coulomb force between them. As the amount of the antibacterial PET masterbatch increased, the adsorbing rate and capacity were increased.

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