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Despite the known sensitivity to sequence mutations of biological polymers, little is known about the effects of errors in sequenced synthetic copolymers. The degradation behaviors of copolyesters, for example, are known to depend on monomer-by-monomer order, yet the contribution of isolated monomer substitutions on hydrolysis behaviors has not been studied. We have developed a synthetic method in which precise quantities of a critical sequence error are doped into a sequenced polyester and studied how hydrolysis behaviors are affected by this distinct and potent sequence-error. The degradation rate proved tolerant to substitutions up to 1% of the monomers but accelerated significantly when the error population was larger. 

Heterogeneous “linkers” are incorporated into polymers for a number of reasons, most commonly to facilitate the coupling of the targeted backbone segments. Due to their inclusion in the backbone, these linkers have the potential to affect the overall properties of the copolymer, even when present in relatively low weight percentages. To characterize the degree of impact of some common linkers, a set of polymers that incorporate both degradable sequenced segments and linkers were synthesized and systematically examined. Seven sequence-controlled olefin containing ester macrocycles were prepared, each with a unique central moiety, including a five-carbon alkyl chain, diethylene glycol, a urea, a thioether, a triazole, a bioaromatic, and an extension of the ester sequence. The macrocycles were polymerized via ED-ROMP to yield seven polymers that vary only in the the linker segment. The properties of all polymers were compared to determine the relative dominance of the different linker types. The properties tested in the study included thermal behavior, mechanical characteristics, hydrolytic degradation and film qualities. The thermal and mechanical properties proved to be dependent primarily on the ability of the linker to promote interchain interactions, as well as the weight fraction of the linker, whereas the hydrolytic degradation was dominated by the relative hydrophobicity of the linker groups. In all cases, the linker identity was a significant contributer to the behavior.