Influence Of Inorganic Fillers Research Articles

The influence of inorganic fillers on the light transmission through resin-matrix composites during the light-curing procedure: an integrative review.

The objective of this study was to perform an integrative review on the effect the inorganic fillers on the light transmission through the resin-matrix composites during the light-curing procedure. A bibliographic review was performed on PubMed using the following search terms: "fillers" OR "particle" AND "light curing" OR "polymerization" AND "light transmission" OR "light absorption" OR "light irradiance" OR "light attenuation" OR "light diffusion" AND "resin composite." The search involvedarticles published in English language in the last 10years. Selected studies reported a decrease in biaxial strength and hardness in traditional resin-matrix composites in function ofthe depth of polymerization. However, there were no significant differences in biaxial strength and hardness recorded along the polymerization depth of Bulk-Fill™ composites. Strength and hardness were enhanced by increasing the size and content of inorganic fillers although some studies revealed a progressive decrease in the degree of conversion on increasing silica particle size. The translucency of glass-ceramic spherical fillers promoted light diffusion mainly in critical situations such as in the case of deep proximal regions of resin-matrix composites. The amount of light transmitted through the resin-matrixcomposites is influenced by the size, content, microstructure, and shape of the inorganic filler particles. The decrease of the degree of conversion affects negatively the physical and mechanical properties of the resin-matrix composites. The type and content of inorganic fillers in the chemical composition of resin-matrix composites do affect their polymerization. As a consequence, the clinical performance of resin-matrix composites can be compromised leading to variable physical properties and degradation. The polymerization mode of resin-matrix composites can be improved according to the type of inorganic fillers in their chemical composition.

Influence of inorganic fillers on the degradation of polypropylene membranes during membrane distillation

Influence of inorganic fillers on the degradation of polypropylene membranes during membrane distillation

无机填料对高密度聚乙烯氧化诱导期的影响

无机填料对高密度聚乙烯氧化诱导期的影响

Influence of inorganic filler on properties of polymeric composites of HEMA–TEOS system

The influence of the composition of 2-hydroxyethyl methacrylate (НEMA) – tetraethoxysilane (TEOS) system on the thermal properties and structural organization of hybrid organic-inorganic composites obtained by the sol-gel method was studied. Formation of composites occurred in the process of concurrent compatible polymerization of mixtures of liquid organic and inorganic components. During the proceeding of sol-gel transformations in organic polymer medium, the inorganic structure is formed in situ in polymer matrix. Complex thermogravimetric and differential thermal analysis of the obtained composites was carried out. The thermograms of the thermal destruction of the samples were obtained, according to which the temperature intervals, the mass loss of the samples and the thermal effects of each stage were determined. The temperature-conversion parameters of thermal destruction of composites were calculated. Based on direct experimental data, taking into account the features of the destruction process, the value of the reduced temperature of composite destruction for the evaluation of their thermal stability was calculated. The dependence of the thermal stability of the material on the amount of inorganic filler in the polymer matrix has been shown. It was found that there is an optimal ratio of HEMA: TEOS, equal to 95:5 % vol., at which the composite is characterized by high thermal resistance. Such character of the inorganic phase influence on the properties of composites of the HEMA–TEOS system can be explained by the so-called “effect of small additions”. That is, with the introduction of minor amounts of the filler, its particles are distributed in a polymer matrix in micro regions with lower density – defective and weakly cross-linked zones. This leads to a decrease in the defectiveness of the polymer matrix due to the “additional ordering” of the defective zones, their compaction and, as a result, to the improving of the thermal properties of the composite. Further increase of the concentration of the inorganic phase in the system leads to a microheterogenization of the structure of the composites and deterioration of their properties. Keywords: organo-inorganic composite, sol-gel system, thermogravimetry, differential thermal analysis, thermal stability.

Investigation into Effect of Ceramic Fillers on Mechanical and Tribological Properties of Bamboo-Glass Hybrid Fiber Reinforced Polymer Composites

Ceramic fillers (TiO2 and ZrO2) having different morphology were used for reinforcement of bamboo-glass hybrid polymer composites. A particular emphasis is focused on special filler (including micro-particle) reinforced thermosets. The mechanical and wear characteristics of bamboo-glass-epoxy hybrid composites, filled with TiO2 and ZrO2,were studied using a tensile test and erosion wear test apparatus. The weight percentage of filler materials in the hybrid composite was varied such as 3, 6 and 9%. Especially, the influence of inorganic fillers on the mechanical and wear performance on the hybrid composites is summarized.

Influence of inorganic fillers on the fire protection of intumescent coatings

Intumescent coatings, mainly composed of ammonium polyphosphate, pentaerythritol and melamine, are widely used in the field of fire protection of steel structures. The objective of this study was to investigate how the presence of two different inorganic fillers (titanium dioxide and mineral fibres) will affect the fire performance of an acrylic-based intumescent coating. In both cases, it was observed that the inorganic filler enabled improvement of the fire-protective behaviour of intumescent paints, maintaining their performance for a longer time. The mode of action was attributed to reinforcement of the char due to the presence of the fillers.

Influence of inorganic fillers on the structural and transport properties of mixed matrix membranes

AbstractIn this study, three types of inorganic fillers—fumed nano‐SiO2, synthesized mesoporous MCM‐41, and zeolite 4A—were incorporated into P84 matrix to prepare mixed matrix membranes. The structural characteristics and transport properties of the resulting composite membranes were investigated. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to observe the dispersion of the filler particles in the composite membranes. TEM micrographs verified that there were no nonselective pores at the particle–polymer interfaces of the composite membranes. Differential scanning calorimetry tests were conducted to investigate the structure of the composite membranes. The glass transition temperatures (Tg) of the P84/MCM‐41 and P84/4A composite membranes were 11 and 30°C, respectively, above that of pure P84 membrane. But, the Tg value for the P84/SiO2 composite membrane decreased by 22°C when compared with that of the P84 membrane. The density of the composite membrane was also measured to calculate its fractional free volume. Gas permeation tests showed that, among the three synthesized composite membranes, the P84/SiO2 membrane had the best performance in terms of gas separation. P84/SiO2 membrane exhibited 20, 63, 59, and 45% increases in the permeabilities of He, O2, N2, and CO2, respectively, above those for the P84 membrane whilst maintaining comparable good selectivities. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Influence of inorganic fillers on the compaction behaviour of porous polymer based membranes

The influence of TiO 2 as inorganic filler in poly(vinylidene fluoride) (PVDF) and polyamideimide (PAI) membranes on various permeation processes has been investigated. PAI/TiO 2 membranes could be prepared without any post-treatment. Furthermore, PAI membranes with 40 wt.% TiO 2 could withstand a temperature treatment at 180 °C with only minor decrease in fluxes. The pore size distribution of the thus treated membranes remained practically unchanged. PVDF/TiO 2 membranes were clearly less susceptible to compaction than pure PVDF membranes during pressure treatment at 30 bar. Additionally, hydrophilic composite membranes with either PVDF or PVDF/TiO 2 supports were tested in vapour permeation experiments for the dehydration of ethanol. The tests covering a temperature range from 78 °C (1 bar) to 135 °C (6.5 bar) revealed that the membranes with the organic–inorganic support showed significantly better permeate quality even at 135 °C accompanied by higher fluxes within the investigated temperature range.

Performance of Polymeric Insulating Materials in Salt-Fog

The paper presents the results of a study conducted on polymeric insulating materials in a salt-fog chamber. The materials examined include high temperature vulcanized (HTV) silicone rubber, ethylene propylene rubber (EPR) and cycloaliphatic epoxy. The influence of inorganic filler, type, concentration and dispersion and the magnitude of the electric stress on the tracking and erosion properties of the materials are reported under high salinity conditions. The presence of filler in EPR material is shown to enhance leakage current. Studies of filler dispersion by an energy dispersive X-ray analysis (EDAX) show non-uniformity in filler concentration where erosion or tracking is initiated. The mechanisms by which the filler operates to impart improved resistance to tracking or erosion is discussed through measurements of surface temperature, released gases, weight loss and leakage current.