Fabrication of microcrystalline cellulose/zinc oxide hybrid composite by hydrothermal synthesis and its application in rubber compounding

• Published in: Journal of applied polymer science Vol. 139; no. 18
• Main Authors: Boopasiri, Supparoek, Sae‐Oui, Pongdhorn, Siriwong, Chomsri
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 10.05.2022; Wiley Subscription Services, Inc
• Subjects: Cellulose; Crosslinking; Crystalline cellulose; crystallization; Density; elastomers; Field emission microscopy; Fourier transforms; Hybrid composites; Infrared analysis; Materials science; Mechanical properties; Natural rubber; Photovoltaic cells; Polymers; Specific surface; structure‐property relationships; Surface area; Thermogravimetric analysis; Zinc oxide; Zinc oxides
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.52065

With great concern of environmental threats, attempts have been made to reduce the consumption of zinc oxide (ZnO) in rubber products. This research aims at fabricating a new type of ZnO by depositing ZnO on microcrystalline cellulose (MCC) surface using an ultrasonic‐assisted hydrothermal process. The concentration ratio of Zn(NO3)2 to NaOH is varied from 1:1 to 1:4. The obtained products, namely MCC‐ZnO, are characterized by various techniques such as field emission scanning electron microscope, Fourier transform infrared spectroscopy, X‐ray diffraction, Brunauer–Emmett–Teller, and Thermogravimetric analysis. Results show that the amount of deposited ZnO and the specific surface area of MCC‐ZnO increase continuously with increasing NaOH concentration. The MCC‐ZnO (1:3) containing approximately 55.6 wt% of deposited ZnO is selected for investigating the curing efficiency in natural rubber (NR) and compared with the commercial ZnO (C‐ZnO). Obviously, the state of cure progressively increases with increasing either MCC‐ZnO or C‐ZnO content. At the same content, MCC‐ZnO exhibits a significantly higher crosslink density than C‐ZnO leading to the superior elasticity and mechanical properties. This could be explained by the greater specific surface area and, thus, the higher reactivity of MCC‐ZnO. Clearly, a considerably lower quantity of MCC‐ZnO is required to attain a similar level of crosslink density or mechanical properties as compared to C‐ZnO. A new alternative and effective curing activator (MCC‐ZnO) for rubber vulcanization is recently fabricated by depositing ZnO particles on microcrystalline cellulose (MCC) via ultrasonic‐assisted hydrothermal process. The state of cure, crosslink density, and mechanical properties of rubber activated by MCC‐ZnO are significantly improved higher than the use of commercial grade, and it also gives more greenery to ecosystem.