Hydroxypropylation of 1,2 Galactomannan by Taguchi's L9 Orthogonal Array Design

Abstract

Hydroxypropyl guar is one of the industrially significant biopolymers. In the present study, hydroxypropylation of guar gum was investigated using Taguchi's L9 orthogonal array design of experiment. Reaction conditions were optimized to obtain higher hydroxypropyl content (%) in the derivatized sample. The optimized conditions comprised 7 mL and 0.12 g of propylene oxide and NaOH respectively, keeping the methanol: water ratio 7 : 3, and reaction time 3 h at 60°C. The hydroxypropyl content of the derivative synthesized under optimized reaction conditions was determined as 0.830 %. The structural changes introduced by the modification were corroborated by FT-IR, 1-D ( 1 H, 13 C, and DEPT-135), and 2-D (HSQC, HMBC, and COSY) NMR spectroscopic analysis. Thermal studies of the hydroxypropyl derivatives vis a vis native guar using TGA, DSC, and DTG indicated better thermal stability of the hydroxypropyl derivative in comparison to the native guar gum. The studies demonstrate that Taguchi's L9 orthogonal array is a statistically sound approach for hydroxypropylation of guar gum involving lesser number of experiments than the conventional approach.

Research on the optimization formula performance and dust reduction effect of mine dust suppressant based on response surface method

“…The orthogonal design method is commonly adopted when conducting the research on multi-component formula of dust suppressant. Rakhi et al (2021) utilized orthogonal design method to investigate the hydroxypropylation reaction of guar gum, synthesized derivatives under optimized conditions. The hydroxypropyl derivative obtained exhibited better thermal stability than natural guar gum.…”