Melamine formaldehyde (MF) resins have been synthesized at different reaction temperature and pH values. Different molar ratios of melamine and formaldehyde were used to synthesize the corresponding resins. The prepared resin samples were characterized by using molecular weight determination viscometry and thermogravimetric analysis (TGA). The maximum percentage of solid content (69.7%) was obt...

this research was conducted to investigate the effect of acetylation and type of resin on fire resistance of one and three layered populus particleboard. populus particles were acetylated at three levels of acetyl content (wpg of 0, 8.39% and 17.27%). in manufacturing of one and three layered boards with acetylated particles in all thickness or surface of the boards two type of resin, urea form...

The purpose of this study was to characterize spatial and temporal variations of carbonyl compounds in Gumi city, where a number of large electronic-industrial complexes are located. Carbonyl samples were collected at five sites in the Gumi area: three industrial, one commercial, and one residential area. Sampling was carried out throughout a year from December 2003 to November 2004. At one ind...

The objective of this project was to use sucrose as a partial substitute for melamine in the synthesis of sucrose–melamine-formaldehyde (SMF) resin. The SMF was synthesized in a base condition. The wet bonding strength, shelf life, and formaldehyde emission of the SMF resin were determined. Fourier transform infrared spectroscopy (FT-IR) and mass spectroscopy (MS) were employed to analyze the c...

Due to the high chemical activity of its filler, fiberboard is a unique material, it's formation can be ensured by reactions wood components. However, under hot pressing modes, typical for dry-process boards, do not have time go through required extent, which requires use special modifiers that enhance fiber. Bi- and polyfunctional compounds - sucrose, carbamide, citric acid were investigated a...

In this study, an experimental phenol–formaldehyde resin with 20% phenol replacement by cashew nut shell liquid (CNSL) was studied and compared with a conventional phenol–formaldehyde resin synthesized totally from petrochemical rawmaterials. The resins were characterizedwith standard lab analysis for their physicochemical specifications, while their thermal properties were studied with thermog...

conclusions according to the results of this study, vitamin e probably improves the harmful effects of formaldehyde on rat kidney tissue. results comparison of the control and formaldehyde groups with the vitamin e group revealed that there were significant differences in lumen size and nuclear color of proximal tubules in rats treated by vitamin e (p < 0.05). cell degeneration, lumen size, num...

Formaldehyde (HCHO) is a toxic air contaminant released indoors from pressed-wood materials and numerous consumer products. Formaldehyde emission data are needed for modeling of indoor personal exposures, health risks, and risk reduction measures. This study determined HCHO emission rates from 55 diverse materials and consumer products under two realistic chamber test conditions, using both tim...