نتایج جستجو برای: using resin modified with 50%furfural. boards cured with conventional uf resin presented the least formaldehyde emission.

تعداد نتایج: 18378502  

Journal: :جنگل و فرآورده های چوب 0
رباب غفاری کارشناس ارشد صنایع چوب و کاغذ، دانشکده منابع طبیعی، دانشگاه تهران،کرج، ایران کاظم دوست حسینی استاد گروه علوم و صنایع چوب و کاغذ، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران علی عبدالخانی استادیار گروه علوم و صنایع چوب و کاغذ، دانشکدة ‏منابع طبیعی، دانشگاه تهران، کرج، ایران سید احمد میرشکرایی استاد دانشکده علوم، دانشگاه پیام نور تهران، تهران، ایران محمد مهدی فائزی پور استاد گروه علوم و صنایع چوب و کاغذ، دانشکده منابع طبیعی، دانشگاه تهران، کرج، ایران

partial replacement of formaldehyde with furfural in the urea-formaldehyde resin on the formaldehydeemission, physical and mechanical properties of particleboard was investigated. the modulus ofrupture (mor), modulus of elasticity (moe), internal bond (ib), water absorption (wa), thicknessswelling (ts) and formaldehyde emission (fe) of poplar particleboards made with the modifiedresins were mea...

پایان نامه :وزارت بهداشت، درمان و آموزش پزشکی - دانشگاه علوم پزشکی و خدمات بهداشتی درمانی مشهد - دانشکده دندانپزشکی 1390

objective: the objective of this study was to investigate the invitro fluoride release of four new self-adhesive resin cements; set (sdi, australia), breeze (pentron, usa), embrace wetbond (pulpdent, usa), g-cem (gc, japan) and to assess the bonding performance of these self-adhesive resin cements for bonding of orthodontic brackets. materials and methods: for fluoride release experiment, six ...

2008
Chung-Yun Hse Feng Fu Hui Pan

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 ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت معلم تهران - دانشکده علوم 1370

determination of uranium in natural water and complex solutions using ion exchange chromatography: a combined procedure using ion exchange chromatography and uv-vis spectrophotometry techniques has been developed to measure uranum in natural water and complex solutions. after conditicing , one hundred milli liters of sample solutions have been passed through an ion exchange column,pachked with ...

2011
Hao Zhang Jing Zhang Shuping Song Guofeng Wu

In this study, nanocrystalline cellulose (NCC) was used for increasing the bonding strength of urea-formaldehyde (UF) resin adhesive, with a reduction of formaldehyde (HCHO) emissions. The surface of NCC was modified by 3-aminpropyltriethoxysilane (APTES) and 3-methacryloxypropyltrimethoxysilane (MPS) for the lack of compatibility with UF resin adhesive. The modified NCC was characterized by X-...

2013
An Mao El Barbary Hassan Moon G. Kim

A previous study of synthesizing low mole ratio urea–formaldehyde (UF) and urea–melamine–formaldehyde (UMF) resins, which included an acidic reaction step at the beginning of the typical resin synthesis procedure to obtain higher uron-type methylene–ether group contents, was repeated with the acidic reaction step extended to a higher viscosity. Compared to previous resins, the synthesized resin...

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...

2009
Chung-Yun Hse

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...

2012
Wei Gao Jianzhang Li

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...

2013
Adya P. Singh Arif Nuryawan Byung-Dae Park

Urea-formaldehyde (UF) resin is widely used as an adhesive for the manufacture of a range of wood and fiber based products. Although the microstructure of this resin has been examined at high resolution by field-emission scanning electron microscopy and atomic force microscopy, transmission electron microscopy (TEM) has thus far not been used, perhaps because of difficulties in ultrathin sectio...

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