Renaturation behavior of xanthan with high molar mass and wide molar mass distribution

Light scattering and viscosity measurements were carried out for thermally renatured xanthan samples with various molar masses and molar mass distributions. The increases in the molar mass, radius of gyration and intrinsic viscosity of a xanthan sample with high molar mass and wide molar mass distribution upon renaturation were smaller than in xanthan samples with lower molar masses and narrower molar mass distributions. This behavior could be explained by the increase in ‘intra-dimer renaturation’ caused by the slower diffusion of xanthan with higher molar mass. The smaller change in the structure and viscosity of xanthan samples with higher molar mass and wider molar mass distribution may contribute to the stability of xanthan as a viscosity enhancer.