Hydroxypropylation reduces gelatinization temperature of corn starch for textile sizing

A series of hydroxypropylated starch (HPS) that can be dissolved in water at 60–65 °C was obtained via two-step method system from corn starch. The structure and property the HPS its gelatinization temperature were characterized by Fourier transform infrared spectrometer, nuclear magnetic resonance spectroscopy (1H NMR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), electron microscopy (SEM), transmission microscope (TEM). It concluded hydroxypropyl mainly bonded on hydroxyl group C2 position glucose residue form C–O–C, substitution level C6 slightly higher than C3 position, as well crystallinity decreased 52.41% to 29.4% due introduction confirmed XRD. At same time, grooves surface granules observed SEM. above-mentioned two synergies promoted permeation molecules microstructure. Moreover, temperatures enthalpy synthetic lower those raw starch, further DSC. This caused with a molar greater 0.1 soluble 65 °C, dissolution state similar 95 (transmittance above 55%), exhibited high slurry stability. Interestingly, compared film showed excellent tensile strength elongation relative humidity 65%, which could attributed hydrophilic ether bond flexible alkyl chain study will provide new way for preparation performance size sizing yarn medium–low temperature.