Respirometry and Cell Viability Studies for Sustainable Polyesters and Their Hydrolysis Products

Abstract

Significant research effort has been directed toward the development of sustainable plastics that are high-performance, bioderived, and/or degrade into nontoxic byproducts in natural or engineered environments (i.e., industrial composting facilities). We report the low cytotoxicity of poly(γ-methyl-ε-caprolactone) (PMCL)-based materials and the hydrolysis product of PMCL, sodium 6-hydroxy-4-methylcaproate. The concentration of sodium 6-hydroxy-4-methylcaproate that leads to 50% cell death (TD 50 ) is 179 mM, a value that is similar to that of the hydrolysis product of polycaprolactone and higher than that of the hydrolysis product of polylactide. We also report the degradability of two PMCL materials with different architectures (cross-linked and linear triblock polymers) under simulated industrial composting conditions. These materials reached high degrees of carbon mineralization (>85%) over the course of 120 days as monitored by CO 2 evolution. Finally, we examined the industrial compostability of a new aromatic polyester, poly(salicylic methyl glycolide). This material reached 89% carbon mineralization after 120 days, an important finding given the recalcitrance toward degradation of ubiquitous aromatic polyesters.

Comparative Study of the Biological Degradation of Poly(3-Hydroxybutyrate-co-3-Hydroxyhexanoate) Microbeads in Municipal Wastewater in Environmental and Controlled Laboratory Conditions

“…Furthermore, a modified Gompertz growth model was used to fit the experimental data for the respirometry method (eq S4), which was used to determine the biodegradation rate coefficient ( R m ) of P3­(HA) samples. The model has been used previously for industrial composting, anaerobic biodegradation, and other microbial growth modeling. − The parameters of the modified Gompertz model are reported in Table . By inspecting the rate constant R m values, it can be seen that there is good agreement among the biodegradation rates of P3­(HA) samples.…”

Sequence‐Controlled Alternating Copolyesters Synthesis via Selective Ring‐Opening Polymerization

“…PSMG was rapidly degradable under industrial composting conditions in later research. [32] The short time for PSMG to reach the maximum conversion of polymer to CO 2 was <30 days, which is much better than PET and even many compostable and sustainable polymers.…”

Bioderived and degradable polymers for transient electronics

“…Accordingly, PLA has become one of the most widely used biodegradable polymers for packaging, multifilament fibers for textile applications, and as substrates for transient electronics. However, there are two major issues with using PLA in transient electronics: (i) the aggressive conditions required for complete degradation, 34 and (ii) the brittleness of the polymer, prompting the need for alternatives.…”

“…3(B)). Recent reports have also found that PGSM can reach 89% carbon mineralization after 120 days under industrial composting conditions, 34 making it an attractive candidate for a wide range of disposal methods.…”

“…For example, PMCL degrades faster than PCL at physiological pH due to its amorphous regions 24 . Additionally, PMCL offers the advantage of non‐cytotoxic byproducts, namely sodium 6‐hydroxy‐4‐methylcaproate (TD 50 of 179 mM) 34 . Thus, both the toxicity of the byproducts and the type of labile linkage merit equal consideration when designing polymers for transient electronics.…”