نتایج جستجو برای: polymer urea formaldehyde

تعداد نتایج: 140518  

Ali Delshad Elaheh Seyed Hosseini Faezeh Karimi Fatemeh Mohammadzadeh Fatemeh Safari, Hossein Abtahi Maryam Mohammadi Mehdi Karimi Shabnam Mohammadi Zahra Seyedi

Background and Aims: Formaldehyde, a colorless aldehyde with pungent odor, has negative effects on systems of the body. Considering, there are a little data about protective substances against kidney damage induced by formaldehyde, the aim of the present study was to examine the effects of different doses of N-acetyl cysteine on biochemical and histopathological parameters in k...

2014
Bekir Cihad Bal İbrahim Bektaş

In this study, we determined the flexural properties and tensile shear strength of five-ply plywood panels produced with eucalyptus (Eucalyptus grandis), beech (Fagus orientalis), and hybrid poplar (Populus x euramericana) using urea-formaldehyde (UF), melamine-urea-formaldehyde (MUF) and phenol-formaldehyde (PF) adhesives. Flexural properties were tested on both parallel and perpendicular to g...

2012
Bekir Cihad Bal İbrahim Bektaş

In this study, the impact bending strengths and specific impact bending strengths were determined for solid wood and laminated veneer lumber (LVL) produced from eucalyptus (Eucalyptus grandis W. Hill ex Maiden), poplar (Populus x euramericana I-214), and beech (Fagus orientalis L.) woods using urea formaldehyde (UF), melamine urea formaldehyde (MUF), and phenol formaldehyde (PF) adhesives. The ...

2013
An Mao El Barbary Hassan Moon G. Kim

Urea-melamine-formaldehyde (UMF) resins with 2.5% and 5.0% melamine levels added at the beginning of the third step of the typical urea-formaldehyde (UF) synthesis procedure were synthesized with an F/(U+M) mole ratio of 1.05 and evaluated as particleboard binders to investigate the positive effects of melamine on the formaldehyde content and physical performance of boards. Resins were tested f...

Journal: :Environmental Health Perspectives 1976
M Spassovski

Results of the toxicological studies of working conditions, general and professional morbidity, and complex examinations carried out on workers engaged in the production of polyamides, polyacrylonitrile fibers, polyester fibers and poly (vinyl chloride) resin, urea-formaldehyde glue, glass fibre materials and polyurethane resins are given. An extremely high occupational hazard for workers in th...

2012
F. Qaderi B. Ayati H. Ganjidoust

Nowadays formaldehyde is used as raw material in many industries. It has also disinfection applications in some public places. Due to its toxicity for microorganisms, chemical or anaerobic biological methods are applied for treating wastewater containing formaldehyde.In this research, formaldehyde removal efficiencies of aerobic biological treatment systems including moving bed biofilm (MMBR) a...

Journal: :Indoor air 2010
D E Hun R L Corsi M T Morandi J A Siegel

UNLABELLED Chronic human exposure to formaldehyde is significantly increased by indoor sources. However, information is lacking on why these exposures appear to persist in older homes with aging sources. We use data from the Relationships of Indoor, Outdoor, and Personal Air study to evaluate 179 residences, most of which were older than 5 years. We assess the dependence of indoor formaldehyde ...

2006
Peep Christjanson Tõnis Pehk Kadri Siimer

The structure formation in acid promoted polycondensation and particularly in alkaline post-treatment with urea was studied by 13C NMR spectroscopy in the three-step synthesis of ureaformaldehyde resins. Trishydroxymethyl urea was identified as the constituent of the mixture of hydroxylmethylated urea derivatives obtained in alkaline conditions. The formation of methylenes linked to secondary o...

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