Carbohydrate Polymers 95 (2013) 630–636 Contents lists available at SciVerse ScienceDirect Carbohydrate Polymers jo u r n al homep age: www.elsevier.com/locate/carbpol Highly stretchable nanoalginate based polyurethane elastomers Hamed Daemi, Mehdi Barikani ∗ , Mohammad Barmar Department of Polyurethane and Nanopolymers, Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran, Islamic Republic of Iran a r t i c l e i n f o Article history: Received 6 January 2013 Received in revised form 2 March 2013 Accepted 11 March 2013 Available online 19 March 2013 Keywords: Cationic polyurethane Sodium alginate Elastomer Nanoparticles Compatibility a b s t r a c t Highly stretchable elastomeric samples based on cationic polyurethane dispersions–sodium alginate nanoparticles (CPUD/SA) were prepared by the solution blending of sodium alginate and aqueous polyurethane dispersions. CPUDs were synthesized by step growth polymerization technique using N-methyldiethanolamine (MDEA) as a source of cationic emulsifier. The chemical structure and thermal–mechanical properties of these systems were characterized using FTIR and DMTA, respectively. The presence of nanoalginate particles including nanobead and nanorod particles were proved by SEM and EDX. It was observed that thermal properties of composites increased with increasing SA content. All prepared samples were known as thermoplastic-elastomers with high percentages of elongation. Excellent compatibility of prepared nanocomposites was proved by the DMTA data. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction Polymeric nanoparticles have been in focus because of their clinical usages especially for therapeutics and carriers for deliv- ery systems (Goycoolea, Lollo, Remun ˜ ná-López, Quaglia, & Alonso, 2009; Hu, Jiang, Ding, Ge, & Yuan, 2002; Pressly, Rossin, Hagooly, Fukukawa, & Messmore, 2007). Different methodologies including interfacial polymerization, emulsion polymerization, solvent evap- oration, solvent deposition, thermally induced gelation process, nanoprecipitation, emulsification–diffusion and controlled gellifi- cation have been reported for synthesizing polymeric nanoparticles (Chen & Ma, 2004; Daemi & Barikani, 2012; Lee, Jeong, Shin, Kim, & Chang, 2005; Zhao, Carvajal, Won, & Harris, 2007). Natural polysaccharides have been attracted as biopolymers due to their unique properties during last decades (Lee & Mooney, 2012; Pawar & Edgar, 2012; Travinskaya & Savelyev, 2006; Yang, Ren, & Xie, 2011; Zia, Bhatti, Barikani, Zuber, & Bhatti, 2009). Alginic acid and its carboxylic salts are important biopolymers with interesting features such as biocompatibility, biodegradability and the ability of gelation with multivalent cations (Arıca, Bayramo˘ glu, Yılmaz, Bektas ¸ , & Genc ¸ , 2004; De-Bashan & Bashan, 2010; Opasanon, Muangman, & Namviriyachote, 2010). Alginates can be assumed as linear triblock copolymers which contain homopolymeric regions of guluronate (G-blocks) and mannuronate (M-blocks) that inter- spersed in blocks with two groups of 1–4-linked M and G residues (MG-blocks) (Scheme 1) (Li, Fang, Vreeker, & Appelqvist, 2007). These polymers can be used as micro and nano encapsulation ∗ Corresponding author. Tel.: +98 2148662427; fax: +98 2144580021. E-mail address: M.Barikani@ippi.ac.ir (M. Barikani). agents and therefore have found different applications in drug delivery and control release systems (Ahmad, Pandey, Sharma, & Khuller, 2006; Finotelli, Silva, Sola-Penna, Rossi, & Farina, 2010). On the other hand, polyurethanes (PUs) are interesting poly- mers with broad range of applications, which are synthesized from polyaddition reactions of isocyanate and hydroxyl groups (Chattopadhyay & Raju, 2007; Chattopadhyay & Webster, 2009; Lemos, Santos, Santos, Santos, & dos Santos, 2007; Zia, Barikani, Zuber, Bhatti, & Sheikh, 2008). These polymers have very good elasticity, high mechanical strength and abrasion resistance due to specific micro-phase structure formed between the hard and soft segments (Lu & Larock, 2008). Hard segments participate in high temperature properties, while soft segments affect on elas- tomeric properties of polymer at low temperatures (Cristiane, Santos, Delpech, & Coutinho, 2009; Ertema, Yilgor, Kosak, Wilkes, & Zhang, 2012). Traditional applications of solvent-based PUs encounter with some restrictions due to environmental regula- tions regarding volatile organic chemicals (VOCs) (Florian, Jena, Allauddin, Narayan, & Raju, 2010; Wynne, Fulmer, McCluskey, Mackey, & Buchanan, 2011). Conventional PUs are insoluble in water, therefore in order to disperse these polymers in water, hydrophilic groups (including ionic or non-ionic agents) must be added to their backbones (Liu, Xu, Liu, Cai, & Su, 2011). Presence of ionic groups in the structure of polyurethane affords interest- ing interactions between PUDs with important biopolymers and nanoparticles (Mao, Jiang, Luo, Liu, & Bao, 2009). Physical and chemical interactions of PUDs with differ- ent polysaccharides have been reported in recent years. It is noteworthy to note that no report is available on cationic polyurethane/nanoalginate compositions in open scientific liter- ature. It is a common procedure to obtain alginate nanoparticles 0144-8617/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.carbpol.2013.03.039