Synthesis and mechanical properties of bio-sourced polyurethane adhesives obtained from castor oil and MDI-modified cellulose acetate: Influence of cellulose acetate modification |
| |
| Affiliation: | 1. Department of Chemistry, Faculty of Science, University Putra Malaysia, 43400 UPM Serdang, Selangor DE, Malaysia;2. Department of Chemical and Process Engineering, Faculty of Engineering, National University Malaysia, 43600 Bangi, Selangor DE, Malaysia;3. Institute of Tropical Forestry and Forest Products, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia;4. Department of Chemical and Environmental Engineering, Faculty of Engineering, 43400 UPM Serdang, Selangor, Malaysia;1. Department of Polymer and Surface Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, Maharashtra, India;2. Department of Oils, Oleochemicals and Surfactants Technology, Institute of Chemical Technology, Matunga, Mumbai 400019, Maharashtra, India;1. Faculty of Technology, University of Ni?, Leskovac, Serbia;2. Faculty of Technology, University of Novi Sad, Serbia;3. Vin?a Institute of Nuclear Sciences, University of Belgrade, Serbia;4. Department of Chemistry, Biochemistry and Environmental Protection, University of Novi Sad, Serbia;5. Department of Physics, University of Novi Sad, Serbia |
| |
| Abstract: | In this study, cellulose acetate and castor oil have been used to synthesize new eco-friendly alternatives to traditional polyurethane adhesives. First, cellulose acetate (CA) was modified with diphenylmethane-4,4′-diisocyanate (MDI) at different NCO:OH molar ratios, ranging from 2 to 4.53, and then the resulting biopolymers were mixed with castor oil (CO) at 1:1 wt ratio. The fully cured bio-sourced adhesives were rheologically characterized by applying dynamic oscillatory torsional tests at different temperatures (from ?30 up to 200 °C). Furthermore, their adhesion performance on stainless steel and poplar wood substrates was analyzed, by conducting standardized mechanical tests, namely single-lap shear and 180° peel strengths, at room temperature and 100 °C. Fourier transform infrared spectroscopy-attenuated total reflectance along with differential scanning calorimetry and thermogravimetric analysis were also performed. Above a critical NCO:OH ratio, a thermo-rheological simplicity was found within the whole temperature range considered, being able to apply the t-T superposition principle. However, an increase in the temperature led to a depletion in their mechanical performance, thus reducing their temperature range of application. Thermal and spectroscopic analysis corroborated the complete disappearance of free isocyanate during the first few days of curing, and a segmented structure, typical of polyurethanes. Optimum thermo-rheological behaviour and adhesion performance on wood and stainless steel of the bio-sourced polyurethanes studied were found for NCO:OH molar ratios higher than 3.5, which was related to the higher compatibility between hard and soft microdomains. |
| |
| Keywords: | Polyurethane Cellulose acetate and castor oil-based adhesives Rheology Mechanical properties of adhesives Viscoelasticity |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
