Urea-formaldehyde resins modified by melamine were synthesized by four catalysts (H2SO4, HCl, H3PO4, and NaOH/NH4OH) with a F/U/M molar ratio of 1.38/1/0.074. Resin structure and thermal behavior were studied by C-NMR and DSC techniques. For H2SO4, HCl, and H3PO4 catalysts, resins were prepared by two stage pH adjustment: the first pH stage was set at 1.25 (H3PO4 pH 1.60) and second pH stage wa...

To upgrade the performance of urea-formaldehyde (UF) resin bonded particleboards, melamine modified urea-formaldehyde (MUF) resins based on strong acidic pH catalyzed UF polymers were investigated. The study was conducted in a series of two experiments: 1) formulation of MUF resins based on a UF polymer catalyzed with strong acidic pH and 2) determination of the effects of increased melamine co...

For the development of a cost-effective melamine-modified urea formaldehyde resin (MUF), the study evaluated the effects of reaction pH and melamine content on resin properties and bond performance of the MUF resin adhesive systems. Eight resins, each with three replicates, were prepared in a factorial experiment that included two formulation variables: two reaction pHs (i.e., 4.5 and 8.0) and ...

Urea-formaldehyde (UF) resin (F/U: 1.25), melamine-urea-formaldehyde (MUF) resin (F/(U+M): 1.05), and three kinds of wood species including poplar (Populus davidiana Dode), beech (Fagus engleriana Seem.), and eucalyptus (Eucalyptus robusta Smith) were used to produce plywood. The effects of sealing treatment and wood species on the formaldehyde emissions were studied. The anatomical characteris...

BACKGROUND Preservatives present in cosmetics and other industrial products can cause allergic contact dermatitis. The aim of the study was to assess the frequency of allergy to selected preservatives in consecutive patients examined due to contact dermatitis in the Nofer Institute of Occupational Medicine, Łódź, and to establish whether individuals sensitized to formaldehyde react simultaneous...

ABSTRAKPanel kayu merupakan produk yang terbuat dari bahan direkatkan dengan menggunakan resin, perekat digunakan dalam produksi lapis resin urea-formaldehid (UF). Resin UF adalah thermosetting urea dan formaldehid akan mengeras jika dipanaskan dapat dicetak ulang. Pada penelitian ini, pembuatan baku Urea Formaldehyde Concentrate (UFC). Tujuan ini mempelajari pengaruh perubahan sifat kinerja UF...

A powdery product was obtained by the reaction of methylolated melamine with alkyl resorcinols to form melamine-bridged alkyl resorcinols (MARs). The effects of the addition of this powder on the bonding strength and formaldehyde emission of urea–formaldehyde (UF) resins were investigated. Three types of UF resins with a formaldehyde/urea molar ratio of 1.3 synthesized by condensation at pH 1.0...

The objective of this study was to manufacture particleboard made from UF with low formaldehyde (E1) for use in indoor environments. The influence of UF in particles on the formaldehyde emission and its mechanical properties were investigated. The experimental results showed that the formaldehyde emission released decreased linearly with consumption UF-low formaldehyde- particle. Formaldehyde e...