scholarly journals Phase Equilibria and Interdiffusion in Bimodal High-Density Polyethylene (HDPE) and Linear Low-Density Polyethylene (LLDPE) Based Compositions

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 811
Author(s):  
Ildar I. Salakhov ◽  
Anatoly E. Chalykh ◽  
Nadim M. Shaidullin ◽  
Alexey V. Shapagin ◽  
Nikita Yu. Budylin ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Laser Interferometry ◽  
High Density ◽  
Low Density Polyethylene ◽  
Polarization Microscopy ◽  
Low Density ◽  
Scanning Calorimetry ◽  
State Diagrams ◽  
Wide Range ◽  
Temperature Dependences

The compositions based on bimodal high-density polyethylene (HDPE, copolymer of ethylene with hexene-1) and in mixture with monomodal tercopolymer of ethylene with butene-1/hexene-1 (LLDPE, low-density polyethylene) have been studied. Phase equilibrium, thermodynamic parameters of interdiffusion in a wide range of temperatures and ratios of co-components were identified by refractometry, differential scanning calorimetry, optical laser interferometry, X-ray phase analysis. The phase state diagrams of the HDPE—LLDPE systems were constructed. It has been established that they belong to the class of state diagrams of “solid crystal solutions with unrestricted mixing of components”. The paired parameters of the components interaction and their temperature dependences were calculated. Thermodynamic compatibility of α-olefins in the region of melts and crystallization of one of the components has been shown. The kinetics of formation of interphase boundaries during crystallization of α-olefins has been analyzed. The morphology of crystallized gradient diffusion zones has been analyzed by optical polarization microscopy. The sizes of spherulites in different areas of concentration profiles and values of interdiffusion coefficients were determined.

Exploration on compatibilizing effect of nonionic, anionic, and cationic surfactants on mechanical, morphological, and chemical properties of high-density polyethylene/low-density polyethylene/cellulose biocomposites

2015 ◽  
Vol 30 (6) ◽  
pp. 855-884 ◽  
Author(s):  
AK Sudari ◽  
AA Shamsuri ◽  
ES Zainudin ◽  
PM Tahir
Keyword(s):  
Mechanical Properties ◽  
High Density Polyethylene ◽  
Sodium Stearate ◽  
High Density ◽  
Low Density Polyethylene ◽  
Hexadecyltrimethylammonium Bromide ◽  
Low Density ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Compatibilizing Effect

Three types of surfactants, specifically cationic, anionic, and nonionic, at different weight percentages were added into high-density polyethylene/low-density polyethylene/cellulose (HDPE/LDPE/cellulose) biocomposites via melt mixing. The cationic and anionic surfactants which are hexadecyltrimethylammonium bromide (HTAB) and sodium stearate (SS), respectively, were added from 4 to 20 wt%, whereas the nonionic surfactant which is sorbitan monostearate (SM) was added from 1 to 5 wt%. The mechanical testing results exhibited that the addition of HTAB increased tensile strength and tensile modulus, while SS deteriorated mechanical properties, while SM increased impact strength and tensile extension of the biocomposites. Based on the mechanical properties results, optimum weight percentages of HTAB and SM were 12 wt% and 4 wt%, respectively. The scanning electron microscopic micrographs displayed that the amount of cellulose fillers pullout decreased with the addition of HTAB, followed by SM, but it increased with SS. Fourier transform infrared spectra, X-ray diffractometer patterns, thermogravimetric analysis results, and differential scanning calorimetry thermograms have confirmed the presence of physical interactions only with the addition of HTAB and SM. Based on the results, compatibilizing effect was found in HTAB, whereas SM has not showed compatibilizing effect but instead plasticizing effect. However, neither compatibilizing nor plasticizing effect was exhibited by SS.

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.

scholarly journals EFFECTIVENESS OF CERTAIN STABILIZERS ON THE AGEING OF POLYETHYLENE FILMS

1998 ◽  
Vol 6 (6) ◽  
pp. 71-76
Author(s):  
S. JIPA ◽  
R. SETNESCU ◽  
T. SETNESCU ◽  
C. PODINA ◽  
J. MIHALCEA
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Low Density Polyethylene ◽  
Phenolic Antioxidants ◽  
Low Density ◽  
Chemiluminescence Method ◽  
Antioxidant Efficiency ◽  
Polyethylene Films

The effectiveness of different phenolic antioxidants on high-density polyethylene (HDPE) and low-density polyethylene (LDPE) has been studied by the Isothermal chemiluminescence method. The decreasing order of the antioxidant efficiency for these polymers Is as follows: lrganox 1010 >> Etanox 330 > lrganox 1076 (Hostanox 016) > Topanol OC

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