Phase inversion and co-continuity domain in immiscible polyethylene/polystyrene blends

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Frédéric Prochazka ◽  
Romulus Dima ◽  
Jean-Charles Majesté ◽  
Christian Carrot
Keyword(s):  
Electron Microscopy ◽  
Phase Inversion ◽  
Single Point ◽  
Selective Extraction ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Wide Range ◽  
Internal Mixer ◽  
Scanning Electron

Abstract Blends of polystyrene and high-density or linear low-density polyethylene have been prepared in an internal mixer and studied in a wide range of compositions. Phase inversion compositions have been determined using selective extraction and scanning electron microscopy. It appears that phase inversion can occur in a domain of compositions rather than at a single point. The existing models of phase inversion are not complete enough to explain the entire phenomenon, and percolation of each component may be considered to describe the formation of co-continuity.

Effect of the blow-up ratio on morphology and engineering properties of three-layered linear low-density polyethylene blown films

2017 ◽  
Vol 34 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Suthakarn Auksornkul ◽  
Siriwat Soontaranon ◽  
Chonthicha Kaewhan ◽  
Pattarapan Prasassarakich
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Transverse Direction ◽  
Blow Up ◽  
Engineering Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Film Morphology ◽  
Linear Low Density Polyethylene ◽  
Machine Direction

A series of linear low-density polyethylene films were produced using a three-layer co-extrusion machine. How the blow-up ratio and resin characteristics affected the final film morphology and engineering properties were studied. The crystalline morphology and orientation during the blown film process of the low-density polyethylene film were investigated using small-angle X-ray scattering, transmission electron microscopy and scanning electron microscopy. Increasing the blow-up ratio increased the transverse direction molecular orientation and decreased the machine direction orientation. The resulting low-density polyethylene morphology was a regular lamellar stacking parallel to the machine direction. The film morphology strongly influenced the mechanical properties. Increasing the blow-up ratio from 1.7 to 2.8 decreased the machine direction tensile strength by 14% and increased the transverse direction tensile strength up to 27% for both the low-density polyethylene/1-butene and low-density polyethylene/1-octene co-monomers, while the machine direction tear strength increased up to 36% and the transverse direction decreased by 16%. Moreover, the first and second heating characteristics from differential scanning calorimeter showed the inherent crystallinity change with increasing blow-up ratio for both the low-density polyethylene/1-octene and the low-density polyethylene/1-butene copolymer. The crystalline orientation changes induced with increasing blow-up ratio affected the film water vapor and oxygen permeability.

Thermal Properties of Linear-Low Density Polyethylene (LLDPE)/Soya Spent Powder Blends with the Addition of Epoxidised Natural Rubber

2013 ◽  
Vol 795 ◽  
pp. 433-437 ◽  
Author(s):  
S.T. Sam ◽  
N.Z. Noriman ◽  
S. Ragunathan ◽  
O.H. Lin ◽  
H. Ismail
Keyword(s):  
Thermal Properties ◽  
Natural Rubber ◽  
Mixing Time ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Scanning Calorimetry ◽  
Powder Composites ◽  
Powder Content ◽  
Internal Mixer

Soya spent powder as an inexpensive and renewable source has been used as a filler for linear-low density polyethylene (LLDPE) in this study. Linear-low density polyethylene (LLDPE)/soya spent powder composites were prepared by using Haake internal mixer. The mixing time was 10 minutes at 150°C with rotor speed 50 rpm. Epoxidised natural rubber (ENR 50) has been used as a compatibilizer in the present study. The thermal properties of the LLDPE/soya spent powder composites with and without ENR were studied with a differential scanning calorimetry (DSC). The crystallinity of the LLDPE/soya spent powder composites decreased with increasing soya spent powder content. However, the addition of ENR 50 as a compatibilizer increased the crystallinity of the LLDPE/soya spent powder composites.

Simulation of an Industrial Linear Low Density Polyethylene Plant

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Ali Farhangiyan Kashani ◽  
Hossein Abedini ◽  
Mohammad Reza Kalaee
Keyword(s):  
Steady State ◽  
Average Molecular Weight ◽  
Molar Fraction ◽  
Operating Conditions ◽  
Low Density Polyethylene ◽  
Process Equipment ◽  
Flow Index ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Wide Range

In this paper, an industrial linear low density polyethylene (LLDPE) production process including two serried fluidized bed reactors (FBR) and other process equipment was completely simulated in steady state mode. Both of FBRs were considered like two serried continuous stirred tank reactors (CSTR). In this simulation, a kinetic model that is based on a multiple active site heterogeneous Ziegler-Natta catalyst was used for simulation of reactions in two FBRs. Simulator by using this model is able to predict the important attributes of LLDPE like melt flow index (MFI), density (ρ), polydispersity (PDI), numerical and weight average molecular weight (Mn, Mw) and co-polymer molar fraction (SFRAC). On the other hand, this simulator can be applied in wide range of changing in inlet operating conditions. The results of the simulation are compared with industrial data of LLDPE plant. A good agreement is observed between the simulator predictions and actual plant data. Finally, by using of the simulator, the steady state operating conditions for producing different grades of polyethylene are obtained.

A Comparison of Rheological Models and Experimental Data of Metallocene Linear Low Density Polyethylene Solutions as a Function of Temperature and Concentration

2016 ◽  
Vol 12 (3) ◽  
pp. 4322-4339
Author(s):  
Salah Hamza
Keyword(s):  
Experimental Data ◽  
Shear Rate ◽  
Rheological Properties ◽  
Power Law ◽  
Low Density Polyethylene ◽  
Effect Of Temperature ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Shear Rates ◽  
Wide Range

Knowledge of rheological properties of polymer and their variation with temperature and concentration have been globally important for processing and fabrication of polymers in order to make useful products. Basheer et al. [1] investigated, experimentally, the changes in rheological properties of metallocene linear low density polyethylene (mLLDPE) solutions by using a rotational rheometer model AR-G2 with parallel plate geometry. Their work covered the temperature range from  to  and  concentration from  to . In this paper, we reconsider Basheer work to describe the rheological behavior of mLLDPE solutions and its dependence on concentration and temperature.Until now, several models have been built to describe the complex behavior of polymer fluids with varying degrees of success. In this article, Oldroyd 4-constant, Giesekus and Power law models were tested for investigating the viscosity of mLLDPE solution as a function of shear rate. Results showed that Giesekus and power law models provide the best prediction of viscosity for a wide range of shear rates at constant temperature and concentration. Therefore, Giesekus and power law models were suitable for all mLLDPE solutions while Oldroyd 4-constant model doesn't.A new proposed correlation for the viscosity of mLLDPE solutions as a function of shear rate, temperature and concentration has been suggested. The effect of temperature and concentration can be adequately described by an Arrhenius-type and exponential function respectively. The proposed correlation form was found to fit the experimental data adequately.

Tensile Properties LLDPE/Soya Spent Powder Blends: Oven Aging

2013 ◽  
Vol 795 ◽  
pp. 429-432
Author(s):  
S.T. Sam ◽  
N.Z. Noriman ◽  
S. Ragunathan ◽  
H. Ismail
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Aging Time ◽  
Thermal Aging ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Elongation At Break ◽  
Powder Blends ◽  
Internal Mixer

Linear low-density polyethylene (LLDPE)/soya spent powder blends with different blends ratio were prepared by using internal mixer. Soya spent powder was varied from 5 to 40 wt. The thermal degradability was assessed by subjecting the dumbbell sample to oven aging. Thermal aging was carried out for 5 weeks. The degradability was measured by the periodic change in tensile properties of the blend samples. The tensile strength and elongation at break of the blends reduced as increasing the aging time. The effect of degradation was obvious in higher soya spent powder blends.

An experimental study on foaming of linear low-density polyethylene/high-density polyethylene blends

2016 ◽  
Vol 53 (1) ◽  
pp. 83-105 ◽  
Author(s):  
Peyman Shahi ◽  
Amir Hossein Behravesh ◽  
Ali Haghtalab ◽  
Ghaus Rizvi ◽  
Fatemeh Goharpei
Keyword(s):  
Bulk Density ◽  
High Density Polyethylene ◽  
Cell Structure ◽  
High Density ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Polyethylene Blends ◽  
Wide Range ◽  
Foaming Behavior

In this research work, foaming behavior of selected polyethylene blends was studied in a solid-state batch process, using CO2 as the blowing agent. Special emphasis was paid towards finding a relationship between foamability and thermal and rheological properties of blends. Pure high-density polyethylene, linear low-density polyethylene, and their blends with two weight fraction levels of high-density polyethylene (10 and 25%wt.) were examined. The dry blended batches were mixed using an internal mixer in a molten state, and then the disk-shaped specimens, 1.8 mm in thickness, were produced for foaming purposes. The foaming step was conducted over a wide range of temperatures (120–170℃), and the overall expansion and cellular morphology were evaluated via density measurements and captured SEM micrographs, respectively. Three-dimensional structural images were also captured using a high resolution X-ray micro CT for different foamed samples and were compared. Rheological and DSC tests for the virgin and blends were also performed to seek for a possible correlation with the formability. Based on the results, blended polyethylene foams exhibited remarkable expansion and highly enhanced cell structure compared to pure polymers. Bulk density, as low as 0.33 g/cm3, was obtained for blends, while for the virgin high-density polyethylene  and linear low-density polyethylene, bulk density lower than 0.5 g/cm3 was not attainable. The lowest density was observed at a foaming temperature of 10–20℃ above the melting (peak) temperature obtained via DSC test. Rheological characteristics, including storage modulus and cross-over frequency value, were also found to be the indicators for the materials foaming behavior. Moreover, blends with 25% wt. of high-density polyethylene exhibited the highest expansion values over a wider range of temperature compared with 90% linear low-density polyethylene/10% high-density polyethylene.

Tensile Properties and Morphological Studies of Kenaf-Filled Linear Low Density Polyethylene/Poly(Vinyl Alcohol) (LLDPE/PVA/KNF) Composites: The Effects of KNF Loading

2016 ◽  
Vol 1133 ◽  
pp. 156-160 ◽  
Author(s):  
Ai Ling Pang ◽  
Hanafi Ismail ◽  
Azhar Abu Bakar
Keyword(s):  
Tensile Properties ◽  
Vinyl Alcohol ◽  
Tensile Modulus ◽  
Low Density Polyethylene ◽  
Poly Vinyl Alcohol ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Elongation At Break ◽  
Morphological Studies ◽  
Internal Mixer

Tensile properties and morphological studies of linear low density polyethylene (LLDPE)/poly (vinyl alcohol) (PVA)/kenaf (KNF) composites were investigated. The composites with different KNF loading (0, 10, 20, 30, 40 phr) were prepared using a Thermo Haake Polydrive internal mixer at 150°C and 50 rpm for 10 min. The results indicated that tensile strength and elongation at break were decreased with increasing KNF loading, whereas tensile modulus showed the opposite trend. Tensile fractured surfaces observed by scanning electron microscopy showed better interfacial adhesion between LLDPE/PVA and KNF at 10 phr KNF loading.

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