New Insight into the Preparation of Starch-Based Spherical Microgels with Tunable Volume
Journal
Starch/Staerke
Journal Volume
71
Journal Issue
9-10
Start Page
1800288
ISSN
00389056
Date Issued
2019-09-01
Author(s)
Abstract
In this paper, novel, eco-friendly spherical cationic starch (CS) microgels are successfully prepared by partially gelatinizing CS granules, followed by stabilizing the structure with a cross-linker (sodium trimetaphosphate, STMP). Discrete and spherical swollen CS granules are first obtained by partially gelatinizing CS starch at 50 °C for 10 min, without the need for inverse emulsification. Various amounts of STMP are reacted with partially gelatinized CS granules to examine the effect of cross-linking density on the swelling behaviors. Depending on the degree of cross-linking, the average diameter of CS microgels in water ranges from 55 to 75 µm. The STMP cross-linking strengthens the structure of CS microgels through chemical cross-linking (via distarch monophosphate formation) and ionic cross-linking (via trapping unreacted STMP). Upon changing the environmental pH and ionic strength, it is found that the swelling volume of microgel is mainly controlled by the excess cationic groups and chemical cross-linking. Having a relatively stable swelling ratio within a wide pH range (3–9) and a good viscosity thickening ability, the CS microgel shows great potential as a natural thickener (texture stabilizer) in personal care products.
Subjects
cationic starch
rheology
sodium trimetaphosphate (STMP)
starch microgels
swelling behavior
Publisher
Wiley-VCH Verlag
Type
journal article