From Castor Oil-Based Multifunctional Polyols to Waterborne Polyurethanes: Synthesis and Properties |
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Authors: | Yuehong Zhang Zhenqiang Wu Lei Shi Langlang Dai Ruijing Liu Lei Zhang Bin Lyu Shunhua Zhao Vijay Kumar Thakur |
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Affiliation: | 1. College of Bioresources Chemical and Materials Engineering, Xi'an Key Laboratory of Green Chemicals and Functional Materials, Shaanxi University of Science and Technology, Xi'an, 710021 China;2. Zhejiang Hexin Science and Technology Co., Ltd, Jiaxing, 314003 China;3. Biorefining and Advanced Materials Research Centre, Scotland's Rural College, Kings Buildings, Edinburgh, EH9 3JG UK |
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Abstract: | A novel castor oil-based multifunctional polyol (CM) is fabricated through mild thiol-ene photo induced reactions using castor oil (CO) and 1-thioglycerol (MPD) as building blocks. The effect of the reaction time, molar ratio of thiol to carbon–carbon double bond, and the loadings of photo-initiator are optimized. The resulting CM is combined with CO and employed as cross-linkers to prepare castor oil-based water-borne polyurethane emulsion with desirable mechanical properties and water resistance. Owing to the incorporation of CM cross-linker with high hydroxyl value of 371 mg KOH/g (which is 2.27 times higher than that of the CO), the prepared castor oil-based waterborne polyurethane (CMWPU) possesses compacted 3D network structure with high cross-linking degree, leading to improved glass transition temperature (45 °C), tensile strength (10.8 MPa), water contact angle (87.4°), and decreased water absorption rate (16.12%) with 20% CM additions. Overall, this work illustrates the feasibility of introducing bio renewable CM combined with CO to develop castor oil-based WPU employing a sustainable development strategy. |
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Keywords: | castor oil polyol polyurethane thiol-ene click reaction water resistance |
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