The reactions of di-hydroxymethylurea with phenol under alkaline (pH = 10), weak (pH = 6) and strong acidic (pH = 2) conditions were investigated via the 13C-NMR method. Based on the proposed reaction mechanisms, the variations of the structures of different condensed products were analyzed and the competitive relationship between selfand co-condensation reactions was elucidated. The required e...

1. The thermal denaturation of DNA from rat liver was studied spectrophotometrically. In sodium phosphate buffers denaturation led to a single-stranded form having, at 25 degrees , about 25% of the hypochromism of the intact double helix. 2. The hypochromism of the denatured form was the same in 1mm- as in 10mm-sodium phosphate buffer and was scarcely affected by reaction with formaldehyde. The...

Formaldehyde-based adhesives are used in the forestry industry. This is because formaldehyde inexpensive, easy to use and resistant moisture; it also has particular mechanical effects. Formaldehyde both advantages disadvantages. It known that various diseases such as lung cancer occur humans a result of release into air during after board production. In this study, urea glue mixture was prepare...

1,3-dimethylurea (DMU) was used to mimic urea and to model melamine-urea-formaldehyde (MUF) co-condensation reactions. The products of 1,3-dimethylurea-formaldehyde (DMUF), melamine-formaldehyde (MF), and melamine-1,3-dimethylurea-formaldehyde (MDMUF) reactions under alkaline and weak acidic conditions were compared by performing quantitative carbon-13 nuclear magnetic resonance (13C-NMR) analy...