Graft copolymerization of polyDADMAC to cassava starch: Evaluation of process variables via central composite design

• Published in: Industrial crops and products 2015-03, Vol.65, p.535-545
• Main Authors: Razali, M.A.A., Ismail, H., Ariffin, A.
• Format: Article
• Language: English
• Subjects: Cassava starch; Grafting; Polydiallyldimethylammonium chloride; Response surface methodology
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2014.10.010

•This work describes the capability of polyDADMAC to be grafted onto cassava starch.•RSM comprising a three-level and four-variable CCD were implemented.•Variables were monomer ratio into starch (AGU), initiator, time, and temperature.•Monomer ratio is the main contributing factor for grafting percentage. Grafting of polydiallyldimethylammonium chloride (polyDADMAC) to cassava starch was prepared using potassium persulfate (KPS) as a free radical initiator. Response surface methodology (RSM) comprising a three-level and four-variable central composite designs were implemented for variable evaluation and optimization. These variables include the mole ratio of diallyldimethylammonium chloride (DADMAC) to starch (anhydroglucose unit (AGU)), reaction temperature (°C), initiator concentration (mol/L), and reaction time (t). Grafting percentage was considered as a response from the variable interaction. The optimum condition derived were 1.96 [mole ratio of DADMAC to starch (AGU)], 40°C (reaction temperature) 0.09mol/L (initiator concentration) and 4.99h (reaction time). The actual experimental yield was 21.98% at optimum conditions, which is close to the maximum predicted value of 22.80%.