BACKGROUND To facilitate the easier placement of direct resin composite in deeper cavities, bulk fill composites have been introduced. The Mechanical stability of fillings in stress bearing areas restored with bulk-fill resin composites is still open to question, since long term clinical studies are not available so far. Thus, the objective of the study was to evaluate and compare the microtens...

The main objective of this work is to compare the difference between microwave heating and conventional thermal heating in fabricating carbon/epoxy composites. Two types of epoxy resin systems were used as matrices, LY5052-HY5052 and DGEBA-HY917-DY073. All composite samples were fabricated using resin transfer moulding (RTM) technique. The curing of the LY5052-HY5052-carbon and the DGEBA-HY917-...

Due to their light weight and high performance, fiberreinforced composites are being increasingly used in various commercial products in aerospace and automotive industries. Emerging new methods such as liquid composite molding (LCM) and resin transfer molding (RTM) offer an economic, versatile, and efficient means for manufacturing geometrically complex, large composites. RTM process consists ...

INTRODUCTION Materials used to fabricate provisional restorations can be classified as acrylics or resin composites. Provisional crows can be either prefabricated or custom made. ACRYLICS These materials have been used to fabricate provisional restorations since the 1930s and usually available as powder and liquid. They are the most commonly used materials today for both single-unit and multi...

Novel α-alumina crystalline nanosheets are used for the preparation of alumina-carbon composites, in which the latter component is phenolic resin-based ordered mesoporous carbon. A unique feature of these composites is perpendicular orientation of ordered mesopores of the carbon to the (001) facets of nonporous α-alumina nanosheets accompanied by significant enlargement of these mesopores in co...

The molecular deformation of cotton cellulose whisker/epoxy resin (CW/EP) and tunicate whisker/poly(vinyl) acetate (TW/PVAc) composites were investigated using Raman spectroscopy. A shift in the 1095 cm Raman peak position is recorded for samples deformed in both tension and compression, which corresponds to the molecular deformation of the cellulose chains within the whiskers. Cyclic molecular...

The influence of the fiber used as reinforcement in resin matrix composite materials submitted to repeated low energy impacts is analyzed. The aramid, glass and carbon fiber composites were submitted to drop weight tests from 0.5m and from 1m. The number of impact events necessary to cause failure was recorded, and the fracture characteristics of each composite were analyzed by optical microsco...

Flowable composite resins are widely used in clinical practice. Bulk Fill flowable resins with improved mechanical and chemical characteristics have recently been introduced. These composites are low-viscosity materials with the reduced percentage of inorganic filler particles and higher amount of resinous components. Consequently, the polymerization process leads to volumetric contraction, but...

Textile composites describe a broad range of polymer composite materials with textile reinforcements, from woven and non-crimp commodity fabrics to three dimensional textiles. In a general manner textile composites are based on textile preforms manufactured by some textile processing technique and on some resin infiltration and consolidation technique. Due to the complex three-dimensional struc...

Since their discovery in 1991, carbon nanotubes (CNTs) have been considered as the next-generation reinforcement materials to potentially replace conventional carbon fibers for producing super-high-performance lightweight composites. Herein, it is reported that sheets of millimeter-long multi-walled CNTs with stretch alignment and epoxidation functionalization reinforce bismaleimide resin, whic...