کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5014851 | 1463464 | 2017 | 30 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Modification of urea-formaldehyde resin adhesives with blocked isocyanates using sodium bisulfite
ترجمه فارسی عنوان
اصلاح چسب های رزین اوره فرمالدئید با ایزوسیانات مسدود شده با استفاده از بیسولفیت سدیم
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کلمات کلیدی
رزین اوره فرمالدئید، ایزوسیانات مسدود شده بیسولفیت سدیم، رزین هیبرید، تخته سه لا،
موضوعات مرتبط
مهندسی و علوم پایه
سایر رشته های مهندسی
مهندسی مکانیک
چکیده انگلیسی
Polymeric 4-4 diphenyl methane diisocyanate (pMDI) was blocked with an aqueous sodium bisulfite solution to obtain water-dispersible blocked pMDI (B-pMDI) resin with different HSO3/-NCO mole ratios for the modification of urea-formaldehyde (UF) resin. Fourier transform infrared (FTIR) spectra of the B-pMDI resin clearly showed that all isocyanate groups of the pMDI resin were successfully blocked by sodium bisulfite. As the HSO3/-NCO mole ratio increased, the de-blocking temperature of the B-pMDI resin also increased. Two addition levels (1% and 3%) of the B-pMDI resin with different HSO3/-NCO mole ratios were mixed with UF resins and used as an adhesive for plywood. The gel time of the UF/B-pMDI resins decreased to a minimum at a mole ratio of 0.9 and then increased with the HSO3/-NCO mole ratio, and was consistent with the peak temperature (Tp). However, as the HSO3/-NCO mole ratio increased, the viscosity of the modified UF resins by 1% B-pMDI resin addition slightly increased, whereas those of modified resins with 3% B-pMDI resin addition rapidly increased. The adhesion strengths of plywood bonded with the hybrid resins were greater for 1% B-pMDI resin addition than for 3% B-pMDI resin addition. Formaldehyde emission of plywood bonded with the UF/B-pMDI resins significantly decreased up to 34% by the addition of B-pMDI resin at a mole ratio of 1.8. These results suggest that the modification of UF resins by mixing with water-dispersible B-pMDI resin can be a method for improving the water resistance and formaldehyde emission of UF resins for wood-based composites.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Adhesion and Adhesives - Volume 73, March 2017, Pages 118-124
Journal: International Journal of Adhesion and Adhesives - Volume 73, March 2017, Pages 118-124
نویسندگان
Muhammad Adly Rahandi Lubis, Byung-Dae Park, Sang-Min Lee,