Objective This study investigated the wear resistance of injection-molded thermoplastic denture base resins using nanoindentation instrument. Materials and methods Six injection-molded thermoplastic denture base resins (two polyamides, two polyesters, one polycarbonate, one polymethylmethacrylate [PMMA]) and a PMMA conventional heat-polymerized denture-based polymer control were tested. Elastic...

Six thermoplastic resins and conventional acrylic resin were examined to characterize their mechanical and physical properties, water sorption, solubility, flexural strength, modulus of elasticity, tensile strength and color stability. Thermoplastic resins for non-metal clasp dentures exhibiting low water sorption and solubility offer hygienic advantages. Since they have a low modulus of elasti...

The previous study on low mole ratio urea-formaldehyde (UF) and ureamelamine–formaldehyde (UMF) resins synthesized in the typical way as particleboard binders was repeated with the inclusion of a strong acidic reaction step at a mole ratio of 2.7 in the beginning of the resin synthesis procedure. The resulting UF and UMF resins showed longer storageand pot-lives, longer gel times, and the parti...

A new group of synthetic resins (the ethoxyline or epoxide resins) has been widely accepted in industry during the last few years. These resins, thanks to their novel properties as adhesives and casting resins, are used in the modern manufacture of various kinds of apparatus, of electrical equipment, of automobiles, and of aircraft. They are usually supplied in the form of two reactive componen...

Currently, divinylbenzene cross-linked polystyrene (DVB-PS) is the polymer of choice for use in solid-phase organic synthesis (SPOS). While much research has been directed toward the optimization of linker groups for the attachment of compounds to the polymer, the development of new polymers themselves has been relatively neglected. In an attempt to overcome the shortcomings of DVB-PS and to de...

The wear resistance of microfilled and conventional composite resins, was examined, using two sizes of abrasive particles for polishing. The mechanical properties of the composite resins were also studied and evaluated in relation to wear. Conventional composites showed much lower wear resistance than the microfilled resins. The amalgam and human enamel abraded with 10ƒÊm SiC particles, had str...

Flame retardants, such as inorganic fillers or halogenated resins, are incorporated into composites either as additives or reactive materials. In order to improve processability and mechanical properties, as well as reduce smoke toxicity, a method is being developed to introduce highly effective, inexpensive flame retardant materials into thermoset resins. Superabsorbent polymers (SAP) can be l...

Frankincense and myrrh are without a doubt the worlds two most important resins. Although other resins, such as pine, copal, styrax, and dragon blood have played important roles in ethnobotanical medicine, none have been as widely distributed and universally utilized, as economically important, or so highly regarded. This paper presents an overview of these valuable trees and the history, cultu...

This paper establishes an infrared spectral identification key for five natural resins (shellac, sandarac, mastic, copal and rosin) based on their absorbance band positions. These resins may be identified when used in mixtures, such as furniture finishes, at concentrations as low as 1%. Computer methods of deconvolution and spectral subtraction are used to augment this process. The method was v...