Contents lists available at ScienceDirect Industrial Crops & Products journal homepage: www.elsevier.com/locate/indcrop Ionic liquid mediated technology for fabrication of cellulose film using gutta percha as an additive Jikun Xu, Bingchuan Liu, Jingping Hu ⁎ , Huijie Hou ⁎ School of Environmental Science & Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China ARTICLE INFO Keywords: Cellulose Hybrid film Ionic liquid Gutta percha Physicochemical properties ABSTRACT A great paradigm for state-of-the-art biomaterials is to use renewable lignocelluloses with ionic liquid-based green regimes. Novel transparent films were successfully prepared from the purified eucalyptus cellulose by the moderate incorporation of gutta percha (GP, 5–15%) using 1-butyl-3-methylimidazolium acetate ([bmim]OAc) as a versatile solvent. The refined GP was obtained from Eucommia ulmoides Oliver after hot-water extraction, alkaline treatment, enzymatic hydrolysis, and extended petroleum ether purification. The cellulose/GP films exhibited a well-distributed and smooth structure, and the crystalline structure of composite films was trans- formed from cellulose I to II. The incorporation of 5–10% GP obviously improved the tensile strength of films (129–139 MPa) as compared to the pure cellulose film (81 MPa). Moreover, the novel hybrid films showed excellent thermal stability and oxygen barrier property as a result of the reinforcement by GP. The cellulose/GP films with prominent tensile strength, thermal stability and oxygen permeability could be tuned via varying the ratio of GP to cellulose matrix, which can be exploited as a potential candidate of pollution-free, biodegradable and renewable cellulose-based composites for the substitute of petroleum derived packaging materials. 1. Introduction The recent upsurge of research interest has been dedicated on the development of biodegraded and green biomaterials from lig- nocellulosic biomass as a potential alternative of fossil-derived mate- rials to reduce environmental pollution resulted from non-biodegrad- able plastic films (Cao et al., 2010; Fernandes et al., 2009). Crystalline polysaccharides of biomass are auspicious for noteworthy and rapidly growing applications ranging from advanced energy storage, electro- nics, and catalyst or enzyme supports to tissue engineering and biolo- gical devices (Huang et al., 2017). Among them, cellulose is the most abundant polysaccharide in lignocelluloses, which possesses un- paralleled physicochemical properties such as biodegradability and biocompatibility and has a large number of current and potential ap- plications (Siró and Plackett, 2010). There is no doubt that cellulose- based materials have attracted vast research interests in the fields of fibers, films, food casings, and membranes (Qi et al., 2009; Turner et al., 2004). However, cellulose has often suffered from solubility problems due to the presence of hydrogen bonds, hindering the im- provement of their processability, fusibility, and functionality (Pinkert et al., 2009). To date, only a limited number of cellulose solvent sys- tems have been found, for example, LiCl/N,N-dimethylacetamide (DMAc), N-methylmorpholine-N-oxide (NMMO) (Zhang et al., 2005). As the best one of amine-oxides, NMMO system is the solely in- dustrialized solvent for the manufacture of regenerated cellulose fibers and films. However, these solvents have some limitations such as vo- latility, toxicity, unsafety, difficult recovery, and instability in appli- cation (Zhang et al., 2005). Ionic liquids (ILs), the low-melting point salts that are liquids at temperature below 100 °C, have recently found to be used as excellent solvents for cellulose (Wang et al., 2012; Zhang et al., 2014). As the novel and multifaceted media, ILs have a series of superior properties, such as admirable thermal stability, negligible vapor pressure, and tunable properties with respect to hydrophobicity, polarity, and solvent miscibility through appropriate combination of anions and cations (Brandt et al., 2013; Petkovic et al., 2011). Thanks to these unique properties of ILs, the IL-mediated technology has been considered as an efficient method to produce novel cellulosic hybrid composites. ILs with acetate anions have been expounded to exhibit excellent solvating power, low melting points and viscosities, low toxicity and corrosivity, and high hydrogen bonding acceptor abilities (Sun et al., 2009). An impressive recyclability of 1-butyl-3-methylimi- dazolium acetate ([bmim]OAc) was also affirmed (Xu et al., 2017). Representatively, films have been facilely prepared by the regeneration of the biopolymers from solutions in acetate ILs (Abdulkhani et al., 2013; Soheilmoghaddam et al., 2014). In general, the packaging composites are potentially subjected to a http://dx.doi.org/10.1016/j.indcrop.2017.06.020 Received 27 February 2017; Received in revised form 5 June 2017; Accepted 9 June 2017 ⁎ Corresponding authors at: School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074, China. E-mail addresses: hujp@hust.edu.cn (J. Hu), houhuijie@hust.edu.cn (H. Hou). Industrial Crops & Products 108 (2017) 140–148 0926-6690/ © 2017 Elsevier B.V. All rights reserved. MARK