| تعداد نشریات | 285 |
| تعداد نشریات سازمان | 83 |
| تعداد شمارهها | 3,092 |
| تعداد مقالات | 34,514 |
| تعداد مشاهده مقاله | 49,345,336 |
| تعداد دریافت فایل اصل مقاله | 79,807,047 |
اصلاح چوب پالونیا بادی متیلول دی هیدروکسی اتیلناوره اصلاحشده (mDMDHEU) و بررسی تأثیر آن بر برخی ویژگیهای فیزیکی | ||
| تحقیقات علوم چوب و کاغذ ایران | ||
| مقاله 12، دوره 32، شماره 3 - شماره پیاپی 60، آبان 1396، صفحه 436-449 اصل مقاله (315.8 K) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22092/ijwpr.2017.110668.1415 | ||
| نویسندگان | ||
| محمد هادی رضوانی* 1؛ آیسونا طلائی2؛ حسینعلی رجبی چم حیدری3 | ||
| 1گروه علوم و تکنولوژی صنایع چوب، دانشکده مهندسی عمران، دانشگاه تربیت دبیر شهید رجایی، تهران | ||
| 2عضو هیات علمی صنایع چوب، دانشکده مهندسی عمران، دانشگاه تربیت دبیر شهید رجایی تهران، ایران | ||
| 3گروه علوم و تکنولوژی صنایع چوب، دانشکده مهندسی عمران، دانشگاه تربیت دبیر شهید رجایی تهران | ||
| چکیده | ||
| یکی از راهکارهای مهم افزایش گستره کاربرد اصلاح خواص چوب، بهرهگیری از گروههای عاملی فعال در ساختار چوب یا به اصطلاح آغشته کردن با ترکیبات N- متیلول است. هدف از این تحقیق، بررسی ویژگیهای فیزیکی چوب پالونیا پس از اصلاح با رزین دیوارهای Polycrease ECR، به نام دی متیلول دی هیدروکسی اتیلن اوره اصلاح شده (mDMDHEU) بود. نمونههای آزمون فیزیکی بر اساس استاندارد ASTM و EN تهیه گردیدند و به روش سلول تهی اصلاح شده در دو سطح غلظت 15 و 25 درصد از رزین اشباع شدند. پلیمریزاسیون رزین تحت اعمال دما در آون در بازه زمانی 24 ساعت، بهترتیب در دو سطح دمای 145 و 155 درجه سانتیگراد انجام شد. درصد افزایش وزن، تورم حجمی، جذب آب، واکشیدگی حجمی، اثر ضد واکشیدگی، آبشویی و زاویه تماس اندازهگیری شد. افزایش سطح غلظت mDMDHEU، به افزایش وزن و حجیمشدگی دیواره سلولی چوب منتهی شد. بیشترین درصد افزایش وزن (70/10 درصد) و ضریب حجیمشدگی (85/6 درصد) در سطح 25 درصد mDMDHEU، و دمای 145 درجه سانتیگراد تعیین شد. در مقایسه با چوب اصلاح نشده، ثبات ابعاد چوب اصلاح شده با mDMDHEU، در اثر افزایش سطح جذب پلیمر، بهبود یافته و جذب آب کاهش داشته است، بهطوریکه بیشترین پایداری ابعاد در سطح حاوی 25 درصد mDMDHEU، و دمای 145 درجه سانتیگراد اندازهگیری شد. بهعلاوه تیمار mDMDHEU، به آبشویی مقاوم بود. اندازهگیری زاویه تماس، بهبود آبگریزی چوب پس از اصلاح را تأیید کرد. اصلاح با mDMDHEU، بهبود معنیدار خواص فیزیکی را بههمراه داشت. بهبود مقاومت فیزیکی چوب اصلاح شیمیایی شده را میتوان بهکاهش رطوبت، حجیمشدن دیواره سلولی و مسدود شدن منافذ در اثر واکنشپذیری بالای mDMDHEU، با پلیمر دیواره سلول چوب نسبت داد. | ||
| کلیدواژهها | ||
| ویژگی های فیزیکی؛ (Polycrease ECR (mDMDHEU؛ چوب پلیمر دیوارهای؛ جذب آب؛ ضریب حجیم کنندگی | ||
| عنوان مقاله [English] | ||
| Modification of Paulownia Wood with methylolated dimethyloldihydroxyethylenurea (mDMDHEU) and the investigation of its effect on Some of Strength Properties | ||
| نویسندگان [English] | ||
| Mohammad Hadi Rezvani1؛ Aisona Talaei2؛ Hosseinali Rajabi Cham Heidari3 | ||
| 1Wood Science and Technology Department, Faculty of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran | ||
| 2Wood Science and Technology Department, Faculty of Civil Engineering, shahid Rajaee Teacher Training University, Tehran, Iran | ||
| 3Wood Science and Technology, Faculty of Civil Engineering, University of Shahid Rajaee Teacher Training, Tehran, Iran | ||
| چکیده [English] | ||
| One of the main strategies to develop the extent of wood modification is using active functional groups in wood structure or the so-called impregnation with modified N-methylol compound. The aim of this study was to evaluate the physical properties of paulownia wood after modify with Polycrease ECR Cell wall resin, to name modified dimethylol-dihydroxyethyleneurea (mDMDHEU). Physical test samples were prepared according to ASTM and EN standard and treated with pressure vessel method at two concentration levels; 15 and 25 percent of soluble resin. For polymerization, treated samples were heated in oven for 24-hour periods at 145 and 155 ºC respectively. Weight percent gain (WPG), bulking, water soaking, swelling, anti-swelling efficiency (ASE), leaching and contact angle were determined. High mDMDHEU concentration increased the weight gain and cell wall bulking. Highest weight percent gain (10.70%) and bulking efficiency (6.85%) in to levels of 25% were determined at 155 ˚C. In comparison with the unmodified wood, the mDMDHEU modified wood due to absorbed polymer enhancement exhibited improved dimensional stability and reduced water uptake, and maximum dimensional stability were determined in samples modified using to level 25% mDMDHEU containing solutions and curing temperature 155 ºC. Moreover, mDMDHEU treatment was resistant to leaching. Contact angle measurement further confirmed the improved hydrophobicity of wood after modification. Modification with mDMDHEU improved significantly the physical properties. The improve of the resistance of chemically modified wood exposed to can be attributed to the reduction of wood moisture, bulking of cell walls and cell cavities blocking affect to dominant reactivity mDMDHEU with cell wall wood polymer. | ||
| کلیدواژهها [English] | ||
| physical properties, Polycrease ECR (mDMDHEU), Cell Wall WPC, water absorption, bulking efficiency | ||
| مراجع | ||
|
- Adamopoulos, S., Hosseinpourpia, R., and Mai, C., 2015. Tensile strength of handsheets prepared with macerated fibres from solid wood modified with cross-linking agents. Holzforschung, 69(8), 959-966.
- Aydemir, D., Gunduz, G., Altuntas, E., Ertas, M., Sahin, H. T., and Alma, M. H., 2011. Investigating changes in the chemical constituents and dimensional stability of heat-treated hornbeam and uludag fir wood. BioResources, 6(2), 1308-1321.
- El Mansouri, N. E., Yuan, Q., and Huang, F., 2011. Study of chemical modification of alkaline lignin by the glyoxalation reaction. Bioresources, 6(4), 4523-4536.
- Evans, P. D., 2009. Review of the weathering and photostability of modified wood. Wood Material Science and Engineering, 4(1-2), 2-13.
- Gérardin, P., 2016. New alternatives for wood preservation based on thermal and chemical modification of wood—a review. Annals of Forest Science, 73(3), 559-570.
- Ghorbani, M., and Kaki, R., 2016. Investigation on physical behavior of styrene wood-polymer in different concentrations of monomer. Iranian Journal of Wood and Paper Industries, 7(2), 231- 239.
- Gunduz, G., Aydemir, D., and Karakas, G., 2009. The effects of thermal treatment on the mechanical properties of wild Pear (Pyrus elaeagnifolia Pall.) wood and changes in physical properties. Materials & Design, 30(10), 4391-4395.
- Hill CAS., 2006. Wood modification. Chemical, thermal and other processes. John Wiley & Sons Ltd., Chichester, pp 239.
- Hu, L., Pan, H., and Zhou, Y. Z. M., 2011. Methods to improve lignin reactivity as phenol substitute and as replacement for other phenolic compounds: A brief review. Bioresources, 6(3), 3515-3525.
- Ibrahim, N. A., Allam, E. A., El-Hossamy, M. B., and El-Zairy, W. M., 2008. Options for enhancing performance properties of easy-care finished cellulose/wool blended fabrics. Polymer-Plastics Technology and Engineering, 47(3), 281-292.
- Kaki, R., and Ghorbani, M., 2013. Investigation of Water Absorption and Dimensional Stability of Beech Impregnated With Methylmethacrylate. Journal of Forest and Wood Products (JFWP) (Iranian Journal of Natural Resources), 329-338.
- Klüppel, A., and Mai, C., 2013. The influence of curing conditions on the chemical distribution in wood modified with thermosetting resins. Wood science and technology, 47(3), 643-658.
- Krause, A., Wepner, F., Xie, Y., and Militz H., 2008. Wood protection with dimethyloldihydroxy-ethyleneurea and its derivatives. American Chemical Society, Washington DC, pp 356–371.
- Lee, J. K., Lee, J. E., Park, S. C., Cho, H. D., Yoo, H. W., Kim, Y. S., and Ahn, D. J., 2015. A Study on Water Repellent Effectiveness of Natural Oil-Applied Soil as a Building Material. Open Journal of Civil Engineering, 5(01), 139.
- Lei, H., Pizzi, A., and Du, G., 2008. Environmentally friendly mixed tannin/lignin wood resins. Journal of Applied Polymer Science, 107, 203-209.
- Li, Y., Dong, X., Lu, Z., Jia, W., and Liu. Y., 2012. Effect of polymer insitu synthesized from methyl methacrylate and styrene on theorphology, thermal behavior and durability of wood. Journal of Applied Polymer Science, (10), 1-8.
- Lopes, D. B., Mai, C., and Militz, H., 2015. Mechanical properties of chemically modified portuguese pinewood. Maderas. Ciencia y tecnología, 17(1), 179-194.
- Lopes, D. B., May, C., and Militz, H., 2013. Physical properties of Portuguese pinewood chemically modified. Ciência & Tecnologia dos Materials, 25(2), 121-128.
- Mamiński, M., Kozakiewicz, P., Jaskółowski, W., Chin, K. L., San H’ng, P., and Toczyłowska-Mamińska, R., 2016. Enhancement of technical value of oil palm (Elaeis guineensis Jacq.) waste trunk through modification with 1, 3 dimethylol-4, 5-dihydroxyethyleneurea (DMDHEU). European Journal of Wood and Wood Products, 74(6), 837-844.
- Militz, H., and Norton, J., 2013. Performance testing of DMDHEU-modified wood in Australia. International Research Group on Wood Protection IRG/WP 13-30613, Stockholm, Sweden.
- Militz, H., Schaffert, S., Peters, B. C., and Fitzgerald, C. J., 2011. Termite resistance of DMDHEU-treated wood. Wood Science and Technology, 45(3), 547-557.
- Mirzaei, Gh., Mohebby, B., and Tabarsa, T., 2012. Collapsibility and Wettability of Hydrothermally Treated Wood. Iranian Journal of Wood and Paper Industries, 3: 1-11.
- Petrič, M., Knehtl, B., Krause, A., Militz, H., Pavlič, M., Pétrissans, M., and Gérardin, P., 2007. Wettability of waterborne coatings on chemically and thermally modified pine wood. Journal of Coatings Technology and Research, 4(2), 203-206.
- Petrissans, M., Gerardin, P., and Serraj. M., 2003. "Wettability of heat-treated wood". Holzforschung, 57(3), 301-307.
- Schindler, W. D., and Hauser P. J., 2004. Chemical finishing of textiles. Wood head Publishing Limited, Cambridge, England, 5, 51-73.
- Sobhani Oskouie, F., Ghorbani, M., and Amininasab, S. M., 2016. The effects of modification with silan compound on physical properties of poplar wood (Popolus Deltoids). Iranian Journal of Wood and Paper Science Research, 3: 458-471.
- Susheel, K., Kaith, B. S., and Kaur. I., 2009. Pretreatments of natural fibers and their application as reinforcing material in polymer composites —a Review. Polymer Engineering & Science, 49(7), 1253-1272.
- Talaei, A., and Rezvani, M. H., 2016. Influence of Chemical Modification with Polycrease ECR on the Functional Performance of Poplar wood Polymer. Iranian Journal of Wood and Paper Science Research, 32(1), 33-46.
- Talaei, A., Ahmadi, A., and Rassam. Gh., 2015. Study on leaching of copper nanoparticles in combined impregnation densification treatments of wood after accelerated aging. Iranian Journal of Wood and Paper Industries, 6(1), 159- 165.
- Verma, P., Junga, U., Militz, H., and Mai, C., 2009. Protection mechanisms of DMDHEU treated wood against white and brown rot fungi. Holzforschung, 63(3), 371-378.
- Xie, Y., Xiao, Z., Grüneberg, T., Militz, H., Hill, C. A., Steuernagel, L., and Mai, C., 2010. Effects of chemical modification of wood particles with glutaraldehyde and 1, 3-dimethylol-4, 5-dihydroxyethyleneurea on properties of the resulting polypropylene composites. Composites Science and Technology, 70(13), 2003-2011.
- Xu, S., and Wang, Z. L., 2011. One-dimensional ZnO nanostructures: solution growth and functional properties. Nano Research, 4(11), 1013-1098.
- Yan, Y., Dong, Y., Li, C., Chen, H., Zhang, S., and Li, J., 2015. Optimization of reaction parameters and characterization of glyoxal-treated poplar sapwood. Wood science and technology, 49(2), 241-256.
- Yang, H., Yang, C. Q., and He, Q., 2009. The bonding of a hydroxy-functional organophosphorus oligomer to nylon fabric using the formaldehyde derivatives of urea and melamine as the bonding agents. Polymer Degradation and Stability, 94(6), 1023-1031. | ||
|
آمار تعداد مشاهده مقاله: 1,357 تعداد دریافت فایل اصل مقاله: 741 |
||