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| 1 | The effect of urea pretreatment on the formaldehyde emission and properties of straw particleboard显示文摘For manufacturing low-formaldehyde emission particleboard from wheat straw and urea-formaldehyde (UF) resins using urea treatment for indoor environments, we investigated the influence of urea treatment on the formaldehyde emission, physical and mechanical properties of the manufactured particleboard. Wheat straws were treated at three levels of urea concentration (5%, 10%, 15%) and 95℃as holding temperature. Wheat straw particleboards were manufactured using hotpress at 180℃and 3 MPa with two types of UF adhesive (UF-45,UF-91). Then the formaldehyde emission values, physical properties and mechanical properties were considered. The results show that the formaldehyde emission value was decreased by increasing urea concentration. Furthermore, the results indicate that the specimens under urea treatment have better mechanical and physical properties compared with control specimens. Also specimens under urea treatment at 10% concentration and UF-91 type adhesive have the most optimum physical and mechanical strength. | Hojat Hematabadi Rabi Behrooz | 2012 | Journal of Forestry Research2012，23，3： | 2 |
| 2 | Effect of cellulose characteristic and hydrolyze conditions on morphology and size of nanocrystal cellulose extracted from wheat straw 显示文摘 | Maryam Rahimi Rabi Behrooz | 2011 | International Journal of Polymeric Materials2011，60，8： | 1 |
| 3 | Effect of cellulose characteristic and hydrolyze conditions on morphology and size of nanocrystal cellulose extracted from wheat straw 显示文摘 | Maryam Rahimi Rabi Behrooz | 2011 | International Journal of Polymeric Materials2011，60，80： | 1 |
| 4 | Effect of Amine Type on Lignin Modification to Evaluate Its Reactivity in Polyol Construction for Non-Isocyanate Polyurethanes(NIPU)显示文摘Polyols are groups of organic compounds which contain carbon and are randomly linked to other atoms,especially carbon-carbon and carbon-hydrogen.These compounds are mainly used as reactants to make other polymers.Among biopolymers,lignin is regarded as the base of a new polymer in polyol construction.The present study aimed to investigate the effects of amine type(diethylenetriamine and ethylenediamine)on the modification of lignin-based polyols,so as to provide an alternative to petroleum polyols and,in turn,increase functional groups and reduce their harm to humans’health and the environment.To this aim,first,lignin was extracted from raw liquor.Next,the extracted lignin was reacted with diethylenetriamine(DETA)and ethylenediamine(EDA).Finally,the Mannich method was used for the reaction between amine lignin and propylene carbonate.The results of the Fourier Transform Infrared(FTIR)spectroscopy analysis showed that modification with DETA led to more structural change in lignin and peak 1100 indicates the presence of C–O bond related to urethane bonds in modified lignin.Moreover,adding propylene carbonate to aminated lignin did not result in much change in the results of the FTIR analysis.Additionally,urethane bonds can be seen in the results of GPC at 400℃–500℃.Furthermore,a slight decrease in thermal stability was observed in lignin modified with amine and propylene carbonate,compared to the raw lignin sample. | Saeed Kazemi Najafi Farhood Najafi Antonio Pizzi Fatemeh Hassani Khorshidi Rabi Behrooz | 2023 | Journal of Renewable Materials2023，11，5： | 0 |
| 5 | Color and Gloss Changes of a Lignin-Based Polyurethane Coating under Accelerated Weathering显示文摘The purpose of this research study was to investigate the properties of polyurethane coatings based on lignin nano-particles.For this purpose,the prepared coatings were applied to pine wood surfaces and weathered artificially.Subsequently,color and gloss of the coatings were measured before and after the weathering test.Field emission scanning electron microscopy(FE-SEM)micrographs prepared from the coatings showed that the average size of nano-particles in the polyurethane substrate was approximately 500 nm.Nuclear magnetic resonance(13C-NMR)spectroscopy showed that strong urethane bonds were formed in the nano-lignin-based polyurethane.Differential calorimetric analysis(DSC)test revealed that the glass-transition temperature(Tg)of lignin nanoparticles modified with diethylenetriamine(DETA)was 112.8℃ and Tg of lignin nano-particles modified with ethylenediamine(EDA)was 102.5℃,which is lower than the Tg of un-modified lignin(114.6℃)and lignin modified with DETA(126.8℃)and lignin modified with EDA(131.3℃).The coatings modified with lignin nano-particles had a greater change in gloss.The lignin nano-particles in the modified coating are trapping hydroxyl radicals which reduces photoactivity and yellowing of the polyurethane by about 3 times compared to unmodified polyurethane coatings.After weathering test,the nano-lignin-based coating had a rougher surface with a lower contact angle(0.78°)compared to the unmodified polyurethane coating(0.85°). | Fatemeh Hassani Khorshidi Saeed Kazemi Najafi Farhood Najafi Antonio Pizzi Dick Sandberg Rabi Behrooz | 2024 | Journal of Renewable Materials2024，12，2： | 0 |
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