Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the ...Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the chemical recyclability and regulated the thermal and mechanical properties of the resulting polythioesters.The efficient ring-opening polymerization(ROP)of benzo-fused thiolactone monomers(M)containing different substituents gave rise to high-molecular-weight semi-aromatic polythioesters P(M)s.The resulting P(M)s showcased tunable physical and mechanical properties.The debenzylation of P(M3)was able to generate P(M3-OH)with free hydroxyl sidechains.Notably,chemical recycling of the resulting P(M)s back to their corresponding monomers via bulk thermal depolymerization achieved high efficiency(>95%yield,99%purity),establishing a closed-loop lifecycle.展开更多
Developing polymers that can be chemically recycled signifies a considerable prospect to polymer scientists to tackle the increasing plastic crises but is still plagued with certain limitations in architecture/perform...Developing polymers that can be chemically recycled signifies a considerable prospect to polymer scientists to tackle the increasing plastic crises but is still plagued with certain limitations in architecture/performance diversity and depolymerization activity.Polythioesters synthesized through ring-opening polymerization(ROP)of cyclic thioesters monomers are captivating materials owing to the labile thioester bonds in polymer chains and the low ring strain energy of thiolactone monomers.In this brief review,the latest advancements in the ring-opening polymerization of dithiolactone and monothiodilactone monomers to prepare chemically recycled polythioesters are summarized.Moreover,the feasibility and challenges in future practical applications of chemically recyclable polythioesters derived from dithiolactone and monothiodilactone will be discussed.展开更多
The accumulation of discarded petroleum-based plastics causes serious environmental crises.Currently,recyclable polymers with neutrality in thermodynamics,such as polyesters,polycarbonates,and polyolefins,have been de...The accumulation of discarded petroleum-based plastics causes serious environmental crises.Currently,recyclable polymers with neutrality in thermodynamics,such as polyesters,polycarbonates,and polyolefins,have been developed as promising alternatives to traditional petroleum-based polymers.However,the chemical recycle of these polymers usually requires high energy input and expensive catalysts.Dynamic covalent bonds,such as thioester and disulfide bonds,have emerged as building blocks for constructing recyclable polymers that can be rapidly degraded/recycled under mild conditions.In this review,we introduce representative studies on recyclable polythioesters and polydisulfides with respect to their synthetic strategies,thermodynamic manipulation,physicochemical properties,and preliminary applications.We also highlight the important role of kinetic factors played in the design of recyclable polymers.Finally,major challenges,perspectives,and future opportunities in the synthesis and applications of polythioesters/polydisulfides are discussed.展开更多
The bacterium Rhodococcus erythropolis MI2 uses 4,4´-dithiodibutyric acid(DTDB)as carbon source to synthesize polythioesters(PTE).The first step for the production of PTE using DTDB is catalyzed by an NADH:flavin...The bacterium Rhodococcus erythropolis MI2 uses 4,4´-dithiodibutyric acid(DTDB)as carbon source to synthesize polythioesters(PTE).The first step for the production of PTE using DTDB is catalyzed by an NADH:flavin oxidoreductase(nox)as it was previously shown in our laboratory,and the second step is catabolized by a putative luciferase-like monooxygenase(Llm).In the current study,experiments were carried out to identify the function of Llm.Hence,the llm gene,which encodes for the Llm protein,was amplified from the genomic DNA of MI2 using polymerase chain reaction and expressed in Escherichia coli BL21 cells.Protein purification was done using His Spin Trap affinity columns.Enzyme assay was carried out using the purified protein and p-coumaric acid as substrate giving a specific activity of 1.6 U/mg protein for the purified Llm.The responsible gene(llm)was deleted in the genome of MI2,and a single deletion mutant was subsequently generated.Finally,growth of the wild-type strain(MI2)and the mutant strain(MI2Δllm)were compared using DTDB or succinate as carbon sources.Whereas the wild type was successfully grown with DTDB or succinate,the llm-negative mutant exhibited low grow with DTDB although it grows very well with succinate.展开更多
Developing new chemically recyclable polymers is important for a circular plastics economy.Herein,we prepared a class of 1,4-dithian-2-one(DTO)with thioether and thioester functionalities.These sulfur-substituted mono...Developing new chemically recyclable polymers is important for a circular plastics economy.Herein,we prepared a class of 1,4-dithian-2-one(DTO)with thioether and thioester functionalities.These sulfur-substituted monomers(DTO)showed excellent reactivity for ring-opening polymerization(turnover frequency(TOF)up to 2.3×10^(4)h^(-1)),which afforded poly(thioetherthioester)s(P(DTO)s)with high air stability,high crystallinity,and commercial high-density polyethylene-like mechanical property(σB=29.59±1.08 MPa andεB=749%±36%).Intriguingly,chemical recycling of P(DTO)to monomer could be accomplished with excellent efficiency in dilute solution(1 min)at room temperature or even from a commodity plastic waste mixture under catalyst-free thermal bulk condition(180°C),thus establishing its circular life cycle.P(Me-DTO)could be applied for selective removal of Hg^(2+)with>99%removal efficiency.More importantly,Me-DTO could be recovered in high yield after utilization for Hg^(2+)adsorption.展开更多
基金financially supported by the National Key R&D Program of China(No.2021YFA1501700)the National Natural Science Foundation of China(Nos.22371194 and 22301197)Fundamental Research Funds from Sichuan University(Nos.2023SCUNL103 and 2024SCUQJTX005)。
文摘Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the chemical recyclability and regulated the thermal and mechanical properties of the resulting polythioesters.The efficient ring-opening polymerization(ROP)of benzo-fused thiolactone monomers(M)containing different substituents gave rise to high-molecular-weight semi-aromatic polythioesters P(M)s.The resulting P(M)s showcased tunable physical and mechanical properties.The debenzylation of P(M3)was able to generate P(M3-OH)with free hydroxyl sidechains.Notably,chemical recycling of the resulting P(M)s back to their corresponding monomers via bulk thermal depolymerization achieved high efficiency(>95%yield,99%purity),establishing a closed-loop lifecycle.
基金supported by grants from the National Science Fund for Distinguished Young Scholars(22325108)National Natural Science Foundation of China(91856113,U21A2089 and 52273015)+2 种基金the National Key Research and Development Program of China(2022YFE0130500)the State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC,PR20232038)Jilin Province and CAS(2022SYHZ0034).
文摘Developing polymers that can be chemically recycled signifies a considerable prospect to polymer scientists to tackle the increasing plastic crises but is still plagued with certain limitations in architecture/performance diversity and depolymerization activity.Polythioesters synthesized through ring-opening polymerization(ROP)of cyclic thioesters monomers are captivating materials owing to the labile thioester bonds in polymer chains and the low ring strain energy of thiolactone monomers.In this brief review,the latest advancements in the ring-opening polymerization of dithiolactone and monothiodilactone monomers to prepare chemically recycled polythioesters are summarized.Moreover,the feasibility and challenges in future practical applications of chemically recyclable polythioesters derived from dithiolactone and monothiodilactone will be discussed.
基金supported by the National Natural Science Foundation of China (22125101)the fellowship of the China Postdoctoral Science Foundation Funded Project (2020M680193)the China Postdoctoral Science Special Foundation Funded Project (2021T140008)
文摘The accumulation of discarded petroleum-based plastics causes serious environmental crises.Currently,recyclable polymers with neutrality in thermodynamics,such as polyesters,polycarbonates,and polyolefins,have been developed as promising alternatives to traditional petroleum-based polymers.However,the chemical recycle of these polymers usually requires high energy input and expensive catalysts.Dynamic covalent bonds,such as thioester and disulfide bonds,have emerged as building blocks for constructing recyclable polymers that can be rapidly degraded/recycled under mild conditions.In this review,we introduce representative studies on recyclable polythioesters and polydisulfides with respect to their synthetic strategies,thermodynamic manipulation,physicochemical properties,and preliminary applications.We also highlight the important role of kinetic factors played in the design of recyclable polymers.Finally,major challenges,perspectives,and future opportunities in the synthesis and applications of polythioesters/polydisulfides are discussed.
基金supported by Alexander von Humboldt(AvH)foundation,Germany(Ref No:IND 1162665 HFST-P)。
文摘The bacterium Rhodococcus erythropolis MI2 uses 4,4´-dithiodibutyric acid(DTDB)as carbon source to synthesize polythioesters(PTE).The first step for the production of PTE using DTDB is catalyzed by an NADH:flavin oxidoreductase(nox)as it was previously shown in our laboratory,and the second step is catabolized by a putative luciferase-like monooxygenase(Llm).In the current study,experiments were carried out to identify the function of Llm.Hence,the llm gene,which encodes for the Llm protein,was amplified from the genomic DNA of MI2 using polymerase chain reaction and expressed in Escherichia coli BL21 cells.Protein purification was done using His Spin Trap affinity columns.Enzyme assay was carried out using the purified protein and p-coumaric acid as substrate giving a specific activity of 1.6 U/mg protein for the purified Llm.The responsible gene(llm)was deleted in the genome of MI2,and a single deletion mutant was subsequently generated.Finally,growth of the wild-type strain(MI2)and the mutant strain(MI2Δllm)were compared using DTDB or succinate as carbon sources.Whereas the wild type was successfully grown with DTDB or succinate,the llm-negative mutant exhibited low grow with DTDB although it grows very well with succinate.
基金supported by the National Key R&D Program of China(2021YFA1501700)the National Natural Science Foundation of China(51903177,U19A2095)+1 种基金the“1000-Youth Talents Program”the Fundamental Research Funds for the Central Universities(YJ201924,YJ202209)。
文摘Developing new chemically recyclable polymers is important for a circular plastics economy.Herein,we prepared a class of 1,4-dithian-2-one(DTO)with thioether and thioester functionalities.These sulfur-substituted monomers(DTO)showed excellent reactivity for ring-opening polymerization(turnover frequency(TOF)up to 2.3×10^(4)h^(-1)),which afforded poly(thioetherthioester)s(P(DTO)s)with high air stability,high crystallinity,and commercial high-density polyethylene-like mechanical property(σB=29.59±1.08 MPa andεB=749%±36%).Intriguingly,chemical recycling of P(DTO)to monomer could be accomplished with excellent efficiency in dilute solution(1 min)at room temperature or even from a commodity plastic waste mixture under catalyst-free thermal bulk condition(180°C),thus establishing its circular life cycle.P(Me-DTO)could be applied for selective removal of Hg^(2+)with>99%removal efficiency.More importantly,Me-DTO could be recovered in high yield after utilization for Hg^(2+)adsorption.
