Agarose based multifunctional materials: Evaluation of thixotropy, self-healability and stretchability

• Published in: Carbohydrate polymers 2014-12, Vol.114, p.306-311
• Main Authors: Chaudhary, Jai Prakash, Chejara, Dharmesh R., Makwana, Dipak, Prasad, Kamalesh, Meena, Ramavatar
• Format: Article
• Language: English
• Subjects: Agarose; Applied sciences; Ester derivatives; Exact sciences and technology; Natural polymers; Physicochemistry of polymers; Self-healing; Starch and polysaccharides; Stretchable material; Thixotropy
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2014.08.024

•Multifunctional ester derivative of agarose has been described.•Agr-GAEst formed gel in ethylene glycol, exhibited excellent thixotropic property.•Gel system exhibited excellent stretching ability (>20 times).•Gel upon cleavage got self-healed with or without external stimuli within 12min.•Multifunctional properties of this material allow for wider applications. This paper reports a microwave assisted one pot facile synthesis of ester derivatives of agarose (Agr-GAEst) through chemical reaction of agarose (Agr) with gallic acid (GA), an organic acid found in many plants employing carbodiimide chemistry. Agr-GAEst was characterised by FT-IR, 13C NMR spectroscopy, thermogravimetric analysis (TGA), DMA measurements, scanning electron microscopy (SEM), UV–vis spectrophotometry and rheometry. The native agarose was insoluble in ethylene glycol, but Agr-GAEst (obtained at an optimized molar ratio of 1: 0.5) formed good quality gel (tanδ∼0.1) at 4% (w/v) concentration. The gel thus obtained exhibited substantial degree of thixotropy (hysteresis loop area=38.73%), rapid self-healing ability (12min) upon complete cleavage of the gel and excellent stretching ability (>20 times of its original length). These types of multifunctional gels would find applications in food and personal health care industries.