maleic-acid and adipic-acid

New salt forms of the antioxidant drug emoxypine (EMX, 2-ethyl-6-methylpyridin-3-ol) with pharmaceutically acceptable maleic (Mlt), malonic (Mln) and adipic (Adp) acids were obtained {emoxypinium maleate, C

Topics: Adipates; Crystallography, X-Ray; Dicarboxylic Acids; Hydrogen Bonding; Ions; Maleates; Picolines; Pyridines; Solubility

The purpose of this study was to investigate the use of different plasticizers in soft acrylic resin materials to reduce leaching of the plasticizer and thus increase the durability of tissue conditioners. Samples were prepared containing different combinations of three types of polymer/copolymer powder and four types of plasticizer liquid (DEHM, DIBA, DAA and DINA). The dynamic viscoelasticity of each sample was measured after water immersion using a dynamic mechanical analyzer. Water absorption, solubility and weight change were also measured. A significant difference was found among the materials regarding dynamic viscoelasticity, water absorption and solubility. The samples containing P-n-BMA had the most stable G' and G'' scores throughout the immersion. P-n-BMA is the most suitable powder together with DEHM as the most suitable liquid component for a tissue conditioner. These results suggest that it is possible to improve the durability of tissue conditioners by combining different polymers and plasticizers.

Topics: Absorption; Acrylic Resins; Adipates; Biocompatible Materials; Chemistry, Pharmaceutical; Dental Materials; Denture Liners; Elasticity; Ethanol; Humans; Humidity; Immersion; Maleates; Materials Testing; Methacrylates; Methylmethacrylates; Plasticizers; Polymers; Polymethacrylic Acids; Powders; Solubility; Solutions; Solvents; Temperature; Tissue Conditioning, Dental; Viscosity; Water

In this work, PM(10) samples were collected in a winter and a summer in Christchurch, a New Zealand city having intensive wood and coal burning and a serious air pollution problem in winter. Oxalic, malonic, succinic, maleic, glutaric and adipic acids in the samples were analysed using ion chromatography. It was suggested that solid fuel burning had large influence on the occurrence of these low molecular weight dicarboxylic acids resulting in significantly higher wintertime concentrations of maleic acid, oxalic acid and glutaric or adipic acid. The most pronounced feature observed was that maleic acid was the second most abundant species of the detected DCAs in the winter (with a mean of 74 ngm(-3) and the highest concentration ever reported of 231 ngm(-3)). In contrast, malonic acid experienced a low abundance in both seasons. The observed seasonal patterns and molecular distribution were inconsistent with those in most other urban areas. On an average, the total detected dicarboxylic acids accounted for about 0.5% of PM(10) mass with a maximum of 1.4% in the winter. The relative importance of different sources to individual dicarboxylic acids varied with seasons and is discussed in detail.

Topics: Adipates; Air Pollutants; Cities; Coal; Dicarboxylic Acids; Environmental Monitoring; Glutarates; Maleates; Molecular Weight; New Zealand; Oxalic Acid; Particle Size; Seasons; Wood