Effect of Flow Fields on Morphology of PP/Nano/CaCO3 Composite and Its Rheological Behavior

Materials ◽  
2005 ◽  
Author(s):  
Han-Xiong Huang ◽  
Guo Jiang ◽  
Shan-Qiang Mao
Keyword(s):  
Crystallization Behavior ◽  
Filler Content ◽  
Melt Flow Index ◽  
Flow Fields ◽  
Flow Index ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Twin Screw

Polypropylene (PP)/nano-calcium carbonate (nano-CaCO3) composite was prepared using a co-rotating, intermeshing twin-screw extruder. The effect of flow fields on the morphology of the nanocomposite was investigated. Transmission electron microscopy (TEM) was used for the determination of the morphology in the nanocomposite. The crystallization behavior of the nanocomposite was studied by using differential scanning calorimetry (DSC) and the melt shear viscosity was investigated by a melt flow index tester. The study showed that the flow field, through appropriately combining the type of the screw elements in this work, plays an important role in developing morphology of the nanocomposite. In addition, it was shown that the melt viscosity for the nanocomposite at the filler content less than 10 wt% is lower than that of neat PP.

Tuning of HDPE Properties for 3D Printing

2018 ◽  
Vol 773 ◽  
pp. 67-71 ◽  
Author(s):  
Paweesinee Chatkunakasem ◽  
Panisa Luangjuntawong ◽  
Aphiwat Pongwisuthiruchte ◽  
Chuanchom Aumnate ◽  
Pranut Potiyaraj
Keyword(s):  
3D Printing ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Crystalline Polymers ◽  
Twin Screw ◽  
Low Crystalline

The objective of this study is to improve high density polyethylene (HDPE) properties for 3D printing by addition of graphene and low density polyethylene (LDPE). Graphene was prepared by modified Hummer’s method. The prepared graphene was characterized by the infrared spectroscopy and the X-ray diffraction analysis (XRD). Graphene/HDPE and LDPE/HDPE composites were successfully prepared through the melt-blending technique using a twin-screw extruder. The melt flow index (MFI) and differential scanning calorimetry (DSC) were employed to characterize neat HDPE and the modified HDPE. FTIR and XRD results show that graphite was successfully changed into graphene completely and MFI of graphene/HDPE and LDPE/HDPE decreased as the amount of graphene and LDPE in the composite blends increased. DSC results show that the addition of low crystalline polymers can reduce a crystallization temperature and crystallinity content.

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 %.

Crystallization Behavior and Mechanical Properties of PP/EVA Blends

2014 ◽  
Vol 1033-1034 ◽  
pp. 869-872
Author(s):  
Kun Yan Wang
Keyword(s):  
Mechanical Properties ◽  
Crystallization Behavior ◽  
Ethylene Vinyl Acetate ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Blending Method ◽  
Twin Screw

Polypropylene (PP)/ethylene-vinyl acetate (EVA) blends were prepared using a twin-screw extruder by melt blending method. The influences of the EVA contents in PP/EVA blends on crystallization behavior and mechanical properties were investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). XRD results show that the EVA not change the crystal structure in the blends but only decrease the intensity of the diffraction peak. DSC results showed that the melting point and crystallization point decreased when EVA added to the blend. The tensile properties of PP/EVA blend become much better.

scholarly journals Recyclability Analysis of Starch Thermoplastic/Almond Shell Biocomposite

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1159
Author(s):  
Ana Ibáñez-García ◽  
Asunción Martínez-García ◽  
Santiago Ferrándiz-Bou
Keyword(s):  
Linseed Oil ◽  
Charpy Impact ◽  
Melt Flow Index ◽  
Flow Index ◽  
Almond Shell ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Visual Properties ◽  
Shell Powder ◽  
Do So

This article is focused on studying the effect of the reprocessing cycles on the mechanical, thermal, and aesthetic properties of a biocomposite. This process is based on starch thermoplastic polymer (TPS) filled with 20 wt% almond shell powder (ASP) and epoxidized linseed oil (ELO) as a compatibilizing additive. To do so, the biocomposite was prepared in a twin-screw extruder, molded by injection, and characterized in terms of its mechanical, thermal, and visual properties (according to CieLab) and the melt flow index (MFI). The analyses carried out were tensile, flexural, Charpy impact tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The effects of the reprocessing were also studied for the biodegradable unfilled TPS polymer. The results showed that TPS and TPS/ASP biocomposite suffer changes progressively on the properties studied after each reprocessing cycle. Furthermore, it was observed that the addition of ASP intensified these effects regarding TPS. However, in spite of the progressive degradation in both cases, it is technically feasible to reprocess the material at least three times without needing to incorporate virgin material.

Thermal Properties Determination of Polypropylene/Rice Straw Biocomposite Foam via DSC

2014 ◽  
Vol 695 ◽  
pp. 216-219
Author(s):  
Nazuha Tugiman ◽  
Zurina Mohamad ◽  
Wan Aizan Wan Abdul Rahman
Keyword(s):  
Thermal Properties ◽  
Rice Straw ◽  
Dicumyl Peroxide ◽  
Polymer Foam ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Blowing Agent ◽  
Foaming Process ◽  
Twin Screw

Polymer foam biocomposites based on polypropylene/rice straw (PP/RS) were successfully prepared by using an extrusion foaming process. The compounding of PP and RS was performed in a twin-screw extruder which was blended with crosslinker; dicumyl peroxide (DCP) and blowing agent; azodicarbonamide (AZ). The foam biocomposite was extruded at temperatures of 180, 190, 190 and 200 °C respectively, which set from the feeder until the die zone. The thermal properties were investigated by using differential scanning calorimetry (DSC).

scholarly journals Influence of the Conditions of Corotating Twin-Screw Extrusion for Talc-Filled Polypropylene on Selected Properties of the Extrudate

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1460 ◽  
Author(s):  
Sasimowski ◽  
Majewski ◽  
Grochowicz
Keyword(s):  
Maximum Tensile Stress ◽  
Extrusion Process ◽  
Twin Screw Extrusion ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Melt Flow Rate ◽  
Test Segment ◽  
Screw Extrusion ◽  
Twin Screw

The aim of the study was to determine the effect of the application of processing screws with a modified test segment in a corotating twin-screw extruder on selected properties of talc-filled polypropylene extrudate. The test segment was built of trilobe kneading elements and its design modifications refered to changing the distance between the kneading elements and the angle of positions of kneading elements that are relative to each other. The performed tests included the production of extrudate with various degrees of talc-filling using five design solutions of the test segment and then measurements of selected properties, such as tensile strength, elongation at maximum tensile stress, and melt flow rate. Structural studies using scanning electron microscope (SEM) and differential scanning calorimetry (DSC) were also carried out. The study includes not only the description of experimental results but also the determination of empirical models describing the dependence of the properties of the obtained extrudate on the conditions of the extrusion process and the design features of the test segment.

Secondary recycled acrylonitrile–butadiene–styrene and graphene composite for 3D/4D applications: Rheological, thermal, magnetometric, and mechanical analyses

2020 ◽  
pp. 089270572092511 ◽  
Author(s):  
Vinay Kumar ◽  
Rupinder Singh ◽  
IPS Ahuja
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Melt Flow Index ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Vibration Sample Magnetometry ◽  
Porosity Analysis ◽  
Butadiene Styrene

This study reports investigation on nano-sized (5–10 nm) graphene (Gr)-reinforced, secondary (2°) recycled acrylonitrile–butadiene–styrene (ABS) as a smart composite material for 3D and 4D applications. Gr was blended (in different weight proportions) with 2°-recycled ABS granules mechanically for selection of composition/proportion after ascertaining rheological property (based upon melt flow index according to ASTM D 1238), thermal stability based upon differential scanning calorimetry, and magnetic property based upon vibration sample magnetometry. The selected compositions/proportions of ABS-Gr composite was further processed with a twin-screw extruder by varying screw temperature and torque. The results of the study suggest that as regards to mechanical properties (peak strength and Shore D hardness) are concerned, the best settings are 20 wt% Gr reinforcement in ABS at a screw temperature 210°C with torque of 0.4 Nm. The corresponding heat capacity and magnetization for the selected composition/proportion was observed as 0.77 J/g and 0.10 × 10−5 emu (+magnetization), 0.080 × 10−5 emu (−magnetization), respectively. The coercivity of the selected compositions ranges from 79.19 Oe to 1260.34 Oe (+coercivity) and 4.64 Oe to 639.50 Oe (−coercivity), whereas the retentivity of the investigated compositions ranges from 2.36 × 10−5 G to 5.44 × 10−4 G (+retentivity) and 4.31 × 10−5 G to 3.48 × 10−5 G (−retentivity). The results have been counter verified based upon optical photo micrographs, porosity analysis, scanning electron microscopy analysis, and energy-dispersive spectroscopy analysis.

Characterization of Bisphenol a Poly(Carbonate) after Multiple Processing Cycles

2010 ◽  
Vol 146-147 ◽  
pp. 713-719
Author(s):  
Xia Gao ◽  
Qin Yong Mi ◽  
Wei Zhang ◽  
Zhao Hui Wang ◽  
Tong Na Mu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Bisphenol A ◽  
Melt Flow Index ◽  
Flow Index ◽  
Processing Conditions ◽  
Screw Extruder ◽  
Twin Screw ◽  
Multiple Processing ◽  
Poly Carbonate

Bisphenol A poly(carbonate) (PC) pellets used for production of 5 gallon drink water bottles were reprocessed in a twin-screw extruder for three processing cycles which simulated to those of PC bottle processing conditions. The reprocessed PC pellets were characterized by its mechanical, rheological, thermal, and optical properties. It was found that the mechanical properties of the reprocessed PC samples are slightly decreased after reprocessed. Whereas no further change was observed for the rheological and thermal properties and molecule weight of the PC samples after the second reprocessing cycles. Moreover, the melt flow index, color, and optical properties changed obviously after two reprocessing cycles.

Tensile Properties and Degradability of Polyvinyl Alcohol and Starch Succinate Blend

2015 ◽  
Vol 1113 ◽  
pp. 122-126
Author(s):  
Mohd Muizz Fahimi bin Mohamed ◽  
Rahmah Mohamed
Keyword(s):  
Polyvinyl Alcohol ◽  
Tensile Properties ◽  
Sun Exposure ◽  
Melt Flow Index ◽  
Visual Observation ◽  
Flow Index ◽  
Screw Extruder ◽  
Soil Burial ◽  
Twin Screw ◽  
Flow Modifier

The purpose of this study was to determine the tensile properties of biodegradable Polyvinyl Alcohol (PVA) impregnated with commercial grade starch succinate (SS). PVA is a hydrophilic and hygroscopic polymer, and inclusion of SS reduces PVA's hygroscopicity and hydrophilicity. The compounding of PVA with SS was prepared by using a twin screw extruder with fixed flow modifier. The ratios of SS were varied between 5% to 20%. Melt flow index, tensile properties, soil burial and sun exposure degradability were investigated in this study. Tensile strength was observed to increase proportionate to the amount of SS incorporated while the blends were found to have greater flexibility as their elongation increases as their modulus dropped. SS was found to have greater flexibility chain which imparted greater elongation during stretching test. Higher content of SS was found to impart better degradation rate as derived from visual observation of the samples exposed to sunlight and soil burial.

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