Development of a spatially structured polymeric matrix under UV irradiation of polylactide-based composites filled with aluminosilicate microspheres

The relevance of the study is conditioned by the fact that increased consumption of synthetic polymers leads to an increase in environmental pollution due to the long decomposition time of plastic waste. As a result, it is necessary to develop polymer composites based on a biodegradable polymer matrix, and to improve the performance properties of finished plastic products, it is necessary to purposefully select cheap and affordable inorganic fillers. Thus, the purpose of this study is to investigate the regularities in the generation of a spatially structured polymer matrix under UV irradiation of polylactide-based composites filled with aluminosilicate microspheres (ASM). The leading approach to the given problem is to melt polymer composites of various compositions and to determine the physical, mechanical, and thermophysical characteristics of the prototypes, including the supermolecular structure of the polymer matrix under the influence of ultraviolet irradiation. The study suggests that the filling of polylactide with ASM particles leads to an increase in the elastic modulus, a decrease in the strength at static rupture and resistance to dynamic destructive effects, as well as heat resistance. Small aluminosilicate microspheres, when added to polylactide, perform the function of nucleation and, even with a small content, increase the crystallinity degree by 3.7 percentage points. In the range of ASM content from 1 pph to 10 pph, the absolute value of the crystallinity degree practically does not depend on the filler concentration in the polymer composite. UV (ultraviolet) irradiation in the presence of air oxygen initiates the thermooxidative destruction of polylactide and leads to the establishment of a spatially structured polymer phase using the electrostatic intermolecular interaction of additionally formed oxygen-containing functional groups in macrochains, as well as partial intermolecular crosslinking during recombination of macroradicals. The establishment of spatial structures in the polymer matrix under UV irradiation determines an increase in the resistance of experimental samples to thermal effects. It is manifested in an increase in the bending temperature under load by 7-10 percentage points, a decrease in the crystallinity degree by 1.2-2.6 percentage points, a decrease in the fluidity of the meltage and also an increase in the glass transition and melting temperature. The materials of the study are of practical value for the development of biodegradable composites based on polylactide filled with inorganic components.

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Physicochemical WPC Modification Techniques

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.887.144 ◽

2021 ◽

Vol 887 ◽

pp. 144-150

Author(s):

A.E. Shkuro ◽

A.V. Artyomov ◽

A.V. Savinovskikh

Keyword(s):

Mechanical Properties ◽

Polymer Composites ◽

Benzoyl Peroxide ◽

Uv Irradiation ◽

Polymer Matrix ◽

Brinell Hardness ◽

Physical And Mechanical Properties ◽

Irradiation Intensity ◽

Wood Polymer ◽

Wood Polymer Composites

The paper studies issues related to physicochemical and chemical techniques for the modification of wood-polymer composites with a thermoplastic polymer matrix (WPCs) to improve their physical and mechanical properties. The physicochemical modification was performed by photochemical crosslinking with the exposure of WPC specimens to UV irradiation. Chemical modification was performed by introducing benzoyl peroxide into the material composition, leading to chemical crosslinking of polyethylene macromolecules of the WPC polymer matrix. As a result of the study, quantitative characteristics of the effect of the benzoyl peroxide content in the composite, as well as the WPC specimen UV irradiation intensity and duration on the basic physical and mechanical properties of the material have been obtained. The efficiency of physicochemical techniques for modifying WPCs has been estimated by changing the specimen properties such as Brinell hardness, water absorption, and impact strength. It has been found that the Brinell hardness increases by 80 % as compared to unmodified WPC specimens. Effective modification of wood-polymer composites with polymer matrices based on high-density polyethylene may lead to a significant improvement in the quality of products made of these materials.

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Expanded vermiculite-filled flexible polymer composites

Journal of Elastomers & Plastics ◽

10.1177/00952443211029038 ◽

2021 ◽

pp. 009524432110290

Author(s):

Mukaddes Sevval Cetin ◽

Ozan Toprakci ◽

Omer Suat Taskin ◽

Abdullah Aksu ◽

Hatice Aylin Karahan Toprakci

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Contact Angle ◽

Polymer Composites ◽

Flame Retardancy ◽

Composite Films ◽

Filler Concentration ◽

High Shear ◽

Flexible Polymer ◽

Shear Mixing

This study focuses on the fabrication and characterization of vermiculite-filled flexible polymer composites. Exfoliated vermiculite was incorporated into triblock thermoplastic elastomer copolymer, styrene- b-(ethylene- co-butylene)- b-styrene (SEBS), at various levels from 1 to 15 wt% by a high shear mixer. The composite films were obtained by the combination of solvent casting and compression molding. The morphological, structural, thermal, and mechanical properties and contact angle of the composites were determined. Some micro-morphological differences were observed between the samples and the difference was assumed to be caused by high shear mixing and filler concentration. High shear mixing was found effective in terms of the detachment of vermiculite layers at all concentrations. However, at low filler loading, that behavior was more obvious. At 1 wt% filler concentration, mechanical properties increased that was probably caused by good filler-matrix interaction stemmed from smaller particle size. At higher vermiculite concentrations, fillers found to show agglomerations that led to a decrease in mechanical strength and strain at break. Elastic and secant modulus showed an increasing trend. Contact angle measurements were carried out to determine the oleophilic character of the samples. An increase in the vermiculite content resulted in higher oleophilic character and the lowest contact angle was obtained at 15 wt% VMT loading. In addition to these, thermal stability, thermal dimensional stability and flame retardancy were improved by the incorporation of VMT. 15 wt% vermiculite-filled sample showed the best performance in terms of thermal stability and flame retardancy.

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Influence of filler on erosion behavior of polymer composites: A comprehensive review

Journal of Reinforced Plastics and Composites ◽

10.1177/0731684418777111 ◽

2018 ◽

Vol 37 (15) ◽

pp. 1011-1019 ◽

Cited By ~ 10

Author(s):

S Vigneshwaran ◽

M Uthayakumar ◽

V Arumugaprabu ◽

R Deepak Joel Johnson

Keyword(s):

Polymer Composites ◽

Polymer Matrix ◽

Erosion Resistance ◽

Polymer Matrix Composites ◽

Research Work ◽

Recent Decade ◽

Extensive Study ◽

Filler Materials ◽

Matrix Composites ◽

Filled Composite

In recent decade, polymer matrix composites were extensively used in various engineering applications owing to their advanced properties over conventional materials and enhanced performance. This motivated the researchers to generate an extensive study and research work on polymer composites. In recent studies, the erosion properties of the polymer composite attract increasing attention among researchers. The potential enhancement in the erosion resistance property of filled composites tempted the researchers to find the feasibility of using various filler materials in polymer matrix for specific erosion resistance applications. However, only limited numbers of literature are available concerning the tribological performance of the filled composite. Hence in this study, an objective was set to review the various literature that explain the erosion characteristics of filled composites.

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Ultraviolet irradiation sensitizes Pseudomonas aeruginosa PAO1 to multiple antibiotics

Environmental Science Water Research & Technology ◽

10.1039/c8ew00293b ◽

2018 ◽

Vol 4 (12) ◽

pp. 2051-2057 ◽

Cited By ~ 1

Author(s):

Fuzheng Zhao ◽

Qing Hu ◽

Hongqiang Ren ◽

Xu-Xiang Zhang

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Resistance ◽

Uv Irradiation ◽

Resistance Genes ◽

Ultraviolet Irradiation ◽

Efflux Pump ◽

Antibiotic Resistance Genes ◽

Regulatory System ◽

Pseudomonas Aeruginosa Pao1 ◽

Multiple Antibiotics

UV irradiation disturbs the regulatory system of efflux pump proteins to sensitize P. aeruginosa to multiple antibiotics. The increasing susceptibility to rifampicin and vancomycin might be caused by UV-mediated mutations in antibiotic resistance genes.

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Shape Memory Behavior of Carbon Composites With Functional Interlayer

Volume 2: Materials; Joint MSEC-NAMRC-Manufacturing USA ◽

10.1115/msec2018-6449 ◽

2018 ◽

Cited By ~ 1

Author(s):

L. Santo ◽

L. Iorio ◽

G. M. Tedde ◽

F. Quadrini

Keyword(s):

Carbon Fiber ◽

Shape Memory ◽

Polymer Composites ◽

Polymer Matrix ◽

Smart Materials ◽

Shape Memory Polymer ◽

Shape Memory Polymers ◽

Carbon Composites ◽

Three Point Bending ◽

Functional Behavior

Shape Memory Polymer Composites (SMPCs) are smart materials showing the structural properties of long-fiber polymer-matrix together with the functional behavior of shape memory polymers. In this study, SM carbon fiber reinforced (CFR) composites have been produced by using a SM interlayer between two CFR prepregs. Their SM properties have been evaluated in comparison with traditional structural CFR composites without the SM interlayer by using an especially designed test. Active and frozen forces are measured during a thermo-mechanical cycle in the three-point bending configuration. Experimental results show that SMPCs are able to fix a temporary deformed shape by freezing high stresses.

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UV-Enhanced Bioactivity of PS/TiO2 Coating Prepared by Layer-by-Layer Self-Assembly Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.434-435.579 ◽

2010 ◽

Vol 434-435 ◽

pp. 579-581

Author(s):

Zhi Xian Zhang ◽

Fan Xiao ◽

Fei Gao

Keyword(s):

Uv Irradiation ◽

Ultraviolet Irradiation ◽

Self Assembly ◽

Raw Material ◽

Layer By Layer ◽

Titanium Coating ◽

Water Contact ◽

Oh Groups ◽

Assembly Method ◽

Assembly Technology

The TiO2 nanopowder was prepared with TiOSO4 as raw material at low temperature by hydrolysis method, and microspheres coated polyethylene and TiO2 were then fabricated on titanium by layer-by-layer self-assembly technology. Using ultraviolet irradiation of titanium coating in distilled water for some time, titanium with enhanced bioactivity was achieved when immersed in simulated body fluid (SBF). The morphology, size and crystal shape before and after ultraviolet irradiation were characterized by scanning electron microcopy (SEM) and X-ray diffraction (XRD). UV irradiation of titanium results in the conversion of Ti4+ to Ti3+ and the generation of oxygen vacancies, which could react with the absorbed water to form basic Ti–OH groups. Compared with the coating non-UV irradiation, the UV-irradiated coatings do not present any obvious differences in morphology, surface roughness, grain size and phase component; however, they have more abundant basic Ti–OH groups thus the water contact angle decreases greatly so the surface become much more hydrophilic.

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Thermal and Electrical Conductivities of Carbon Fibers and Carbon Nanotubes Incorporated Polyurethanes Composites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.442.349 ◽

2010 ◽

Vol 442 ◽

pp. 349-355 ◽

Cited By ~ 1

Author(s):

Shahrul A. Abdullah ◽

Lars Frormann ◽

Anjum Saleem

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotubes ◽

Electrical Resistivity ◽

Carbon Fibers ◽

Polymer Matrix ◽

Filler Concentration ◽

Melt Mixing ◽

Electrical Conductivities ◽

The Matrix ◽

Polyurethane Composites

Single filler polyurethane composites with carbon fibers (CFs) and multi-walled carbon nanotubes (MWNTs) were prepared by melt mixing methods and its thermal as well as electrical resistivity characteristics were investigated. The influences of fillers and mixing methods on thermal and electrical conductivity of CF/- and MWNT/polyurethane composites were investigated and the result shows that the addition of carbon fillers improved the thermal conductivity of the polyurethane composites. Higher filler concentration results in better thermal conductivity because better formation of thermally conductive networks along polymer matrix to ensure the thermal was conducted through the matrix and the network along the polymer composites. The presence of carbon additives improves the electrical resistivity of the materials as well. The present study revealed the potential of carbon as agent for better thermal and electrical conductivities and their properties depend strongly on the dispersion and distribution of the fillers in the polymer matrix.

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