Partial depolymerization of hydroxypropylmethyl cellulose for production of low molar mass polymer chains

Low molar mass (LMM) biopolymers are highly required to design functional nanomaterials, which mainly find application in biomedical fields. However, the synthesis of LMM polymer is a challenging task. In this work, we report a partial enzymatic depolymerization process which allows to produce a series of LMM hydroxypropylmethyl cellulose (HPMC) polymer, with a weight average molar mass (M_w) under and over 10,000 g mol^-1 and low dispersity (Ɖ < 1.5). Variation of the starting HPMC grade, reaction time, and enzyme concentration were the key parameters to control the M_w and yield of the target molecules. This approach provides a versatile way of producing LMM HPMCs with varying degrees of substitution, and having a single reactive aldehyde function at one chain extremity. LMM HPMC can find for instance application as building blocks for the development of new functional molecular architectures.