The physical and mechanical properties of particleboard panels were evaluated relative to various loading levels nanocellulose (NC) boric acid (BA) in the urea-formaldehyde (UF) resin used for panel production. results showed that NC BA reinforcement substantially affected performance panels. It was determined using 3% afforded best thickness swelling (TS), water absorption (WA), moisture conte...

It is shown by enzymatic digestion of chromatin from rat liver or Guerin ascites tumour (GAT) that treatments, which abolish the 180 base pair repeat, as revealed by digestion with micrococcal nuclease (shearing in salt solutions of medium ionic strength, sonication, fixation with formaldehyde in the presence of 5 M urea), have little effect on the 10 nucleotide repeat, observed in deoxyribonuc...

The initiating properties of urea-formaldehyde oligomers with peroxide groups have been studied. For comparison, the activity has examined for polymerization styrene by oligomer based on epoxy Epidian-5 and tert-butyl hydroperoxide. cross-linking investigated using unsaturated oligoesters as a model. chemistry formation substances cross-linked structure studied IR spectroscopy.

The dual activation of acyl phosphonates and formaldehyde tert-butyl hydrazone by a BINAM-derived bis-urea catalyst is the key to achieve high reactivities and enantioselectivities in the synthesis of densely functionalized quaternary α-hydroxy phosphonates. Subsequent high-yielding transformations in a 'one-pot' fashion provide direct access to valuable azoxy compounds and quaternary α-aryl-ph...

Uron resin, a kind of urea-formaldehyde (UF) resin containing much more uron structure, were prepared. Several modi ed UF resins were obtained from mixing uron resins with normal UF resins as well as synthesizing UF resin with uron resin as raw material. is work demonstrated that the introducing of the uron structure reduced free formaldehyde content of UF resin and formaldehyde emission levels...

Urea formaldehyde resins were formulated with vatiables of three reaction pHs (1.0, 4.8, and 8.0 5.0) and three catalysts (sodium hydroxide, sodium hydroxide/ammonium mix, and triethanolamine) . The resins were prepared by placing all formaldehyde and water in reaction kettle and pH was adjusted with sulfnric acid and sodium hydroxide, respectively. Urea was added in 1.5 equal parts at 1 minute...

The objective of this research was to provide a useful approach of polymer synthesis for accelerating the fast cure of phenol-urea-formaldehyde (PUF) resin as wood adhesive by optimizing its structure and composition. The PUF resins containing high contents of very reactive groups such as para-methylol groups were synthesized by reacting methylolurea, phenol, and formaldehyde in the presence of...

Six potentially important wood adhesives for gluing southern pine and white oak flakeboards were evaluated for their perfonnances in steam-injection pressing and conventional platen pressing. Of the six resins tested, polyisocyanate resin perfonned well in both steam injection and conventional platen pressings. Phenol-fonnaldehyde (PF) and melamine urea-fonnaldehyde (MUF) resins perfonned poorl...