Synthesis and physicochemical properties of low-substituted cationic ethers of starch

Cationization of field pea starch in salt-free aqueous suspension

“…At a lower concentration of starch, both the dilution effect of water/liquid and any side reactions which may occur would lead to a lower DS (Khalil, Farag, & Hashem, 1993). Differences in DS such as those caused by starch concentration in the presence of sucrose were not seen in the cationization of starch at a concentration of 35-45% in aqueous suspension when sodium sulfate was used as the swelling inhibitor (Carr & Bagby, 1981) or at 24-42% when sodium chloride was used (Butrim et al, 2008).…”

“…However, at 50 • C and pH 12, the DS and the RE were 0.025 and 50%, respectively. High reaction temperature and high pH with the presence of a low concentration of sugar may cause extensive starch swelling and gelatinization, solubilization of starch molecules, complicated starch recovery from the final washings (Butrim et al, 2008), and also facilitatation of the de-etherification reaction (Wang et al, 2009), resulting in lower DS and RE. However, cationic groups in starch are distributed more uniformly at higher reaction temperatures (Butrim et al, 2008) and at longer reaction times (more than 5 h) as revealed by confocal scanning microscopy (Kuo & Lai, 2007).…”

“…native starch suspension in water or organic solvent and gelatinized starch paste) (Carr & Bagby, 1981;Kweon, Bhirud, & Sosulski, 1996;Lim, Liang, & Seib, 1992;Radosta et al, 2004;Wang et al, 2009). The functional properties of cationic starches depend strongly on starch botanical origin, modification method and medium, type and distribution of cationic groups, and degree of substitution (DS) (Butrim, Butrim, Bil'dyukevich, Yurkshtovich, & Kaputskii, 2008;Haack, Heinze, Oelmeyer, & Kulicke, 2002;Liu, Corke, & Ramsden, 1999;Manelius, Buleon, Nurmi, & Bertoft, 2000;Radosta et al, 2004;Yook, Sosulski, & Bhirud, 1994). In general, in dry cationization process, the cationic reagent reacts on the surface of starch granule with limited penetration inside the granule.…”

“…The effects of reaction conditions, such as starch concentration, cationic reagent molar ratio, temperature, pH and reaction duration, on DS and reaction efficiency in aqueous cationization processes, as well as characterization of cationic starch properties, have been extensively investigated and reported in numerous publications. For example, cationic starch is typically prepared in aqueous suspension at a starch concentration of 30-45% using a swelling inhibitor, such as sodium chloride (Butrim et al, 2008), sodium sulfate (Carr & Bagby, 1981;Yook et al, 1994), calcium chloride (Lim et al, 1992) or organic solvent (Kweon et al, 1996;Kweon, Sosulski, & Bhirud, 1997;Wang et al, 2009), although cationic starch can be prepared in aqueous phase at a low starch concentration (<20%) without using a swelling inhibitor (Kuo & Lai, 2007), which may impact its dispersion properties (Carr & Bagby, 1981). The use of large amounts of salts and solvents during the cationization process result in challenges to waste disposal, salt removal and solvent recovery (Rutenberg & Solarek, 1984;Villwock & BeMiller, 2005) though CHPTAC and EPTMAC are also not without their own negative environmental impact on aquatic ecosystems (NPCAWH (Finland), 2008).…”

Synthesis and physicochemical properties of cationic starches

“…Cationic starches with quaternary ammonium ethers have the broadest application [1] and have been used effectively over the last decades in the production of paper and cardboard to increase the retention of fiber and filler, suppress the disintegration process, and increase the surface strength and rupture strength of paper [2]. Such cationic starches can be prepared by various methods (dry, wet, extrusion) by adding to the starch macromolecule functional groups carrying a positive charge [3][4][5][6]. Of the large number of available reagents, 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTMAC) is used most often.…”