Accurate molar masses of cellulose for the determination of degradation rates in complex paper samples.

•For studying degradation kinetics of complex lignocellulosic papers, the cellulose peak (C) in multimodal the MMD was deconvoluted.•Two deconvolution methods which use SEC-MALS data are proposed to determine Mr without the disturbance of HC or LCC fractions.•Mr, k and Ea close to cotton linter paper were obtained with the deconvolution method based on a calibration curve built with pure cellulose.