Carbohydrate Polymers 104 (2014) 223–230 Contents lists available at ScienceDirect Carbohydrate Polymers j ourna l ho me page: www.elsevier.com/locate/carbpol Physico-chemical properties and thermal stability of microcrystalline cellulose isolated from Alfa fibres Djalal Trache a,∗ , André Donnot b , Kamel Khimeche a , Riad Benelmir b , Nicolas Brosse b a UER Chimie appliquée, Ecole Militaire Polytechnique, BP 17, Alger, Algeria b LERMAB, Faculté des Sciences et Technologies, Université de Lorraine, Vandœuvre-lès-Nancy, France a r t i c l e i n f o Article history: Received 13 November 2013 Received in revised form 10 January 2014 Accepted 16 January 2014 Available online 27 January 2014 Keywords: Microcrystalline cellulose Alfa fibres Chemical treatment Characterization Thermal properties a b s t r a c t In this study, microcrystalline cellulose (Alfa-MCC) was extracted from Alfa fibres using acid hydrolysis method. The molecular weight of the cellulose samples was determined by gel permeation chromatog- raphy. The crystallinities were studied by means of X-ray diffraction and solid state cross polarization magic angle spinning 13 C nuclear magnetic resonance spectroscopy, revealing that Alfa-MCC was more crystalline than the native cellulose isolated from Alfa fibres. The morphology of the celluloses was investigated using scanning electron microscopy, showing a compact structure and a rough surface. Fur- thermore, a good thermal stability was shown for Alfa-MCC. Based on these analyses, Alfa-MCC showed tremendous potential use as composites reinforcing agent, foods stabilizer and pharmaceutical additive. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction Alfa grass or esparto grass (Stipa tenacissima L.) is a perennial tussock grass widely distributed in semi-arid ecosystems of the southern and western Mediterranean basin, mainly in the Maghreb (García-Fayos & Gasque, 2006). The main components of these fibres are cellulose, hemicellulose and lignin. These fibres have tra- ditionally been used as animal feed and raw material for paper industry (Ahrens et al., 1998; Bessadok, Marais, Gouanvé, Colasse, & Zimmerlin, 2007). Utilization of Alfa fibres to produce biodegrad- able composites and thermoplastic materials has been recently published (Ben Brahim & Ben Cheikh, 2007; Maafi, Malek, Tighzert, & Dony, 2010; Nadji, Diouf, Benaboura, Bedard, & Riedl, 2009; Paiva, Ammar, Campos, Cheikh, & Cunha, 2007). The isolation and characterization of microcrystalline cellulose particles (MCC) have been described from various cellulosic sources (Abdullah, 1991; Adel, Abd El-Wahab, Ibrahim, & Al-Shemy, 2011; Bochek, Shevchuk, & Lavrent’ev, 2003; Ejikeme, 2008; Ilindra & Dhake, 2008; Jahan, Saeed, He, & Ni, 2011; Keshk & Mohamed, 2011; Mohamad Haafiz, Eichhorn, & Jawaid, 2013a) and using several pro- cesses of extraction including mechanical treatments (Hanna et al., 2001; Laka & Chernyavskaya, 2007; Liimatainen, Sirviö, Haapala, Hormi, & Niinimäki, 2011), biological treatments (Adel, Abd El- Wahab, Ibrahim, & Al-Shemy, 2010; Janardhnan & Sain, 2006), and ∗ Corresponding author. Tel.: +213 661808275; fax: +213 21863204. E-mail address: djalaltrache@gmail.com (D. Trache). chemical treatments, e.g., acid hydrolysis (see Adel et al., 2011; Ilindra & Dhake, 2008). All these methods lead to different types of MCC, depending on the cellulose raw materials, its pre-treatment, and more crucially on the disintegrating process itself. However, biological methods are desirable because glucose, a useful by- product, is generated; these methods are more expensive and lead to MCC products having a lower crystallinity. Thus, acid hydroly- sis is the conventional method of choice for manufacturing MCC (Adel et al., 2011; Elanthikkal, Gopalakrishnapanicker, Varghese, & Guthrie, 2010; Hanna et al., 2001; Ilindra & Dhake, 2008). Due to its excellent properties, MCC has generated much attention and interest during these few last decades in both aca- demic and industrial fields. In nanocomposite materials, MCC as reinforcing agent is attracting an increasing interest because of its potential advantages such as renewability, biodegradability and high surface area for bonding with resins. In addition, MCC exhibits a broad capacity to allow tailoring or grafting of chemical species to improve the morphology, thermal and mechanical properties of resulting composites (Azizi Samir, Alloin, & Dufresne, 2005; Hoyos, Cristia, & Vazquez, 2013; Mathew, Oskman, & Sain, 2005; Petersson, Kvien, & Oksman, 2007, Mohamad Haafiz, Hassan, Zakaria, Inuwa, & Islam, 2013b; Sun, Lu, Liu, Zhang, & Zhang, 2014a). Because of its chemical inactivity, absence of toxicity, high sorption and great hygroscopicity, MCC has received great interest (1) in pharma- ceutical formulations, as a potential direct compression excipient especially in the design and development of tablets of poorly com- pressible and soluble drug (Chamsai & Sriamornsak, 2013; Kalita, Nath, Ochubiojo, & Buragohain, 2013; Levis & Deasy, 2001; Mallick, 0144-8617/$ – see front matter © 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.carbpol.2014.01.058