Degradation in Order: Simple and Versatile One-Pot Combination of Two Macromolecular Concepts to Encode Diverse and Spatially Regulated Degradability Functions.

The clever one-pot combination of two macromolecular concepts, ring-opening polymerization (ROP) and step-growth polymerization (SGP), is demonstrated to be a simple, yet powerful tool to design a library of sequence-controlled polymers with diverse and spatially regulated degradability functions. ROP and SGP occur sequentially at room temperature when the organocatalytic conditions are switched from basic to acidic, and each allows the encoding of specific degradable bonds. ROP controls the sequence length and position of the degradability functions, while SGP between the complementary vinyl ether and hydroxyl chain-ends enables the formation of acetal bonds and high-molar-mass copolymers. The result is the rational combination of cleavable bonds prone to either bulk or surface erosion within the same macromolecule. The strategy is versatile and offers higher chemical diversity and level of control over the primary structure than current aliphatic polyesters or polycarbonates, while being simple, effective, and atom-economical and having potential for scalability.