AIM The purpose of this study was to evaluate and compare the flexural strength of commercially available acrylic (trevalone) and modified polymethylmethacrylate (PMMA). MATERIALS AND METHODS Four groups were tested; Group 1- control group regular MMA, group 2-2% methacrylic acid, 88% MMA, group 3-16% methacrylic acid, 84% MMA group 4- 20% methacrylic acid, 80% MMA 15 resin specimens of each ...

Introduction: In orthodontic treatment, it is essential to establish a satisfactory bond between enamel and bracket. After the self-etch primers (SEPs) were introduced for the facilitation of bracket bonding in comparison to the conventional etch-and-bond system, multiple studies have been carried out on their shear bond strengths which have yielded different results. This study was aimed at co...

background: the aim of this study was to evaluate the shear bond strength of an antimicrobial and fluoride-releasing self-etch primer (clearfil protect bond) and compare it with transbond plus self-etch primer and conventional acid etching and priming system. materials and methods: forty-eight extracted human premolars were divided randomly to three groups. in group 1, the teeth were bonded wit...

The tensile strength of durable press finished cotton fabrics is significantly reduced as a result of the crosslinking process. In this research, we investigated the effects of acid degradation and crosslinking of cellulose on the mechanical strength of the cotton fabric crosslinked with polycarboxylic acids, and evaluated various factors influencing the mechanical strength of durable press fin...

in production of tissue paper, the adhesion of a liquid adhesive creping aid, compound polymer, as creping aids on the yankee dryer surface was investigated. a compound polymer was prepared based on mixing ratio of poly (amideamine)-epichlorohydrin resin (pae) as an adhesive agent, polyvinyl alcohol (pva) as a modifier agent, and cationic fatty acid (cfa) and ethylene glycol (eg) as release age...

silica refractory bricks are used especially in the metallurgical industries, due to desirable properties suchas high melting point, rigidity, and high temperatures strength. in this research, different amount of sicwere added to silica refractory containing different binders such as borax, boric acid, calcium nitride,sodium tri poly phosphate, sodium hexa meta phosphate (shmp) and lime. physic...

The protonation constant values of salicylic and 5-nitrosalicylic acid werestudied by a combinationof spectrophotometric and potentiometric methods at 25 °C in wide range of ionic strength. The ionicstrength of solutions was kept constant by sodium perchlorate as background electrolyte at 0.10 to 3.0 moldm-3. Potentiometer was calibrated according to Gran method at each of ionic strength. The p...

The novel polymer poly[p-(2,5-dihydroxy)-phenylenebenzobisoxazole] (PBOH) fiber was synthesized in the presence of 2,5-dihydroxyterephthalicacid (DHTA) and 4,6-diamino-1,3-benzenediol in poly(phosphoric acid) (PPA) using typical polycondensation conditions. The crystalline solutions of liquid PBOH in PPA were spun into fibers using dry-jet wet spinning. Furthermore, the thermostability and mech...