Sorbtion Properties of Biodegredable Polymer Materials Based on Low-Density Polyethylene, Modified Chitosans

2015 ◽  
pp. 209-218
2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Jong Won Kim ◽  
Joon Seok Lee

Polyethylene is one of the most commonly used polymer materials. Even though linear low density polyethylene (LLDPE) has better mechanical properties than other kinds of polyethylene, it is not used as a textile material because of its plastic behavior that is easy to break at the die during melt spinning. In this study, LLDPE fibers were successfully produced with a new approach using a dry-jet wet spinning and a heat drawing process. The fibers were filled with carbon nanotubes (CNTs) to improve the strength and reduce plastic deformation. The crystallinity, degree of orientation, mechanical properties (strength to yield, strength to break, elongation at break, and initial modulus), electrical conductivity, and thermal properties of LLDPE fibers were studied. The results show that the addition of CNTs improved the tensile strength and the degree of crystallinity. The heat drawing process resulted in a significant increase in the tensile strength and the orientation of the CNTs and polymer chains. In addition, this study demonstrates that the heat drawing process effectively decreases the plastic deformation of LLDPE.


2021 ◽  
Vol 63 (1) ◽  
pp. 27-33
Author(s):  
Mai Quyen Hoang ◽  
◽  
Thi Thu Nga Vu ◽  
Manh Quan Nguyen ◽  
Severine Le Roy ◽  
...  

Polymers used as insulating materials are increasingly popular in many different fields. In electrical engineering - electronics, polymers are used in high-voltage transmission cables, capacitors, transformers, or as part of an embedded system in the IGBT module thanks to its superior thermal and electrical insulation properties. One of the disadvantages of polymers is the possible accumulation of space charge in the material volume for a long time, leading to an increase in the electric field compared to the original design value. Charge transport models in polymer materials have been increasingly developed to predict the conduction mechanisms under thermal-electrical stress. In this study, from a finite volume method (FVM), the authors developed a charge transport model in low density polyethylene (LDPE) based on the finite element method (FEM). The simulation results of this model are also compared to experimental results and to the FVM model under different electric fields for LDPE.


2021 ◽  
Vol 10 (1) ◽  
pp. 107-112
Author(s):  
Maria Viktorovna Mantrova

The paper is devoted to the study of biostability of polyethylene, polypropylene and polycarbonate in the conditions of Surgut after their presence within a year in different types of soils swamp-podzolic soil, culturosem and urbanozem. The studied types of soils differ in their chemical composition urbanozems are saturated with bases, have a slightly alkaline reaction, they also contain an excess of lead content due to their close location to highways. In the studied soils bacterial microflora prevails over mycoflora, the amount of heterotrophic and lithoautotrophic microflora in urbanozems is especially high, which is due to the high anthropogenic load on these soils. For seeds and seedlings of wheat and radish the stimulating effect of these soils was revealed. Micromycetes isolated from the surface of polypropylene and polyethylene pipes are typical soil saprotrophs that can act as biodestructors of polymers. In the field experiment all the materials under study are biostable, and there was a slight change in the color of the cross-linked polyethylene sample. In the laboratory experiment certain instability of all the materials under study was revealed; their gradation in terms of mushroom resistance (from resistant to unstable) is as follows: low-density polyethylene, polypropylene random-heat-resistant copolymer, polycarbonate, cross-linked polyethylene. The nature of damage to low-density polyethylene (polyethylene film) is superficial, which corresponds to the literature data.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3393
Author(s):  
Özgün Güzdemir ◽  
Sagar Kanhere ◽  
Victor Bermudez ◽  
Amod A. Ogale

With shrinking size of electronic devices, increasing performance and accompanying heat dissipation, there is a need for efficient removal of this heat through packaging materials. Polymer materials are attractive packaging materials given their low density and electrical insulating properties, but they lack sufficient thermal conductivity that inhibits heat transfer rate. Hexagonal boron nitride (BN) possesses excellent thermal conductivity and is also electrically insulating, therefore BN-filled polymer composites were investigated in this study. Results showed successful continuous extrusion of BN-filled linear low-density polyethylene through micro-textured dies that is a scalable manufacturing process. Through-thickness thermal conductivity measurements established that 30 vol% BN content led to an over 500% increase in thermal conductivity over that of pure polymer. Textured film surface provided about a 50% increase in surface area when compared with non-textured films. This combination of increased surface area and enhanced thermal conductivity of BN-filled textured films indicates their potential application for improved convective thermal transport.


2019 ◽  
Vol 298 ◽  
pp. 00130
Author(s):  
Mariya Podzorova ◽  
Yulia Tertyshnaya ◽  
Anatoly Popov

The paper deals with various polymer materials for agricultural purposes. To date, there are many technologies for growing crops that use polymer films: greenhouses, greenhouses, planting seeds in capsules. There are a lot of works on the study of biodegradable compositions based on biopolymers with synthetic polymers, as well as the analysis of the impact of destructive environmental factors on samples. Binary polylactide–low-density polyethylene blends of various compositions were prepared, and their biodegradability in soil and water absorption kinetics. The degree of water absorption is higher for the blends than for the pure polymers. The weight loss is higher upon incubation in laboratory soil compared to open soil. Changes in the specimen macrostructure after exposure to soil were demonstrated by optical microscopy.


2009 ◽  
Vol 34 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Souad Djellalia ◽  
Nassima Benmahmoud ◽  
Tahar Sadoun

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