Hydrogels of starch-g-(tert-butylacrylate) and starch-g-(n-butylacrylate) copolymers: Synthesis and formation

• Published in: Journal of thermal analysis and calorimetry 2010-02, Vol.99 (2), p.659-666
• Main Authors: Fares, Mohammad M., El-faqeeh, Adeeb S., Ghanem, Hasan, Osman, Mohammad E., Hassan, Elfatih A.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Applied sciences; Chemistry; Chemistry and Materials Science; Exact sciences and technology; Inorganic Chemistry; Measurement Science and Instrumentation; Natural polymers; Physical Chemistry; Physicochemistry of polymers; Polymer Sciences; Starch and polysaccharides
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-009-0213-2

The synthesis, characterization, and hydrogel properties of starch-g-( tert -butylacrylate) and starch-g-( n -butylacrylate) copolymers were studied. The optimum conditions for the grafting process of tert -butylacrylate into 1.0 g of starch were as follows: [ tert -butylacrylate] = 0.04 mol/L, [CAN] = 9.0 × 10 −4  mol/L, temperature = 20 °C in 100 mL solution, whereas the results using n -butylacrylate monomer were as follows: [ n -butylacrylate] = 0.04 mol/L, [CAN] = 4.0 × 10 −3  mol/L, temperature = 30 °C in 100 mL solution. The grafting evidences of monomers into starch were done through TG and its derivative DTG for thermal changes and mass losses, scanning electron microscope (SEM) for morphological changes, powder X-ray for crystallinity measurements and FTIR for functional group changes. Acid hydrolysis method was used efficiently to allow the calculations of the viscosity average molecular weight ( M v ) of the grafted chains on starch and consequently the real percent of grafting efficiency (i.e. %GY). The capability of starch-g-( n -BAC) hydrogel to absorb water were found 10 times more than starch-g-( tert -BAC) hydrogel, which were clarified through the X-ray and SEM results.