Article
Polymer Science
Chen Xu, Liying Wang, Yalei Liu, Haining Niu, Yong Shen, Zhibo Li
Summary: This study presents a rapid and controlled ring-opening polymerization (ROP) method to produce closed-loop recyclable polyesters from commercial monomers. The obtained polyesters can be easily recycled back to pristine monomers by heating in the presence of a catalyst. Well-defined triblock copolymers were successfully prepared and used as pressure-sensitive adhesives without any additives. These copolymers can be chemically recycled to recover ethyl lactate and alkyl-& delta;-lactones with high yields.
Review
Polymer Science
Peter McMichael, Xavier Schultze, Henri Cramail, Frederic Peruch
Summary: Environmental concerns have increased due to the production of polymers from fossil resources and resulting waste management and pollution issues. Research on the ring-opening polymerization of cyclic esters to obtain aliphatic polyesters, which are sustainable and have good mechanical performance, biodegradability, and biocompatibility, has increased. Substituted δ-lactones are interesting building blocks as they can be biobased and have unique properties. Although the polymerization of δ-lactones is challenging, various (co)polyesters have been synthesized from them for applications in drug delivery and thermoplastic elastomers. This review focuses on the synthesis and polymerization of substituted δ-lactones, exploring sustainable polyesters with improved properties and minimal environmental impact.
Article
Polymer Science
Qi-Yuan Wang, Meng-Xue Cao, Xiao-Wei Kan, An Lv, Fu-Sheng Du, Zi-Chen Li
Summary: In this study, the monomer 1,4-oxathian-2-one and its oxidized sulfone ester monomer 1,4-oxathian-2-one-4,4-dioxide were synthesized using a one pot two-step method. Three organic catalysts were screened for the ring-opening polymerization (ROP) of 1,4-oxathian-2-one, and bulk ROP of 1,4-oxathian-2-one-4,4-dioxide was achieved. The polymerization kinetics and thermodynamics of 1,4-oxathian-2-one and delta-valerolactone were studied, and the effect of in-chain heteroatom on the crystallization of copolymers was confirmed.
JOURNAL OF POLYMER SCIENCE
(2022)
Article
Polymer Science
Zhengyang Liu, Jinfeng Shi, Na Zhao, Zhibo Li
Summary: In this study, polysiloxanes with unique low temperature flexibility, including polydiethylsiloxane (PDES) and poly(dimethylsiloxane-co-diethylsiloxane) (PMES) copolymers, were successfully synthesized. The cyclic trimeric phosphazene base (CTPB) catalyzed ring-opening polymerization (ROP) at room temperature, resulting in high yields of PDES homopolymers with high molecular weights. Furthermore, the random copolymers of PMES with tunable diethylsiloxane contents were directly prepared via ring-opening copolymerization (ROCP) using CTPB as a catalyst. The controlled copolymer composition and the random distribution of diethylsiloxane and dimethylsiloxane units were confirmed by microstructure characterizations. The thermal property investigations demonstrated the good low-temperature flexibility and thermal stability of PMES copolymers, indicating their potential in extreme environmental applications.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Polymer Science
Shuang Li, Han Lu, Ling Zhu, Meixue Yan, Xiaohui Kang, Yi Luo
Summary: The mechanisms of ring-opening polymerization of L-lactide and trimethylene carbonate using DMAP/Sac as a bifunctional catalyst were investigated using DFT calculations. A new two-component organocatalyst Adenine/Sac was also designed and evaluated for its catalytic performance. The results showed that Adenine/Sac exhibited higher catalytic activity in the ring-opening of L-lactide and trimethylene carbonate.
Article
Polymer Science
Wei Zhou, Chen Xu, Yalei Liu, Yong Shen
Summary: In this study, a series of organobases and ureas were used as binary catalysts for the ring-opening polymerization (ROP) of lactide. By carefully selecting the combination of organobase and bisurea, controlled ROP of l-lactide was achieved, leading to the preparation of well-defined polylactides with various terminal groups. A high-molecular-weight PLA sample with a M-n up to 73.8 kDa was obtained at a low catalyst loading of 0.05 mol% relative to the monomer, and it showed good mechanical properties comparable to commercial PLA.
JOURNAL OF POLYMER RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Yongliang Xia, Pengjun Yuan, Yanping Zhang, Yangyang Sun, Miao Hong
Summary: This study reports the efficient conversion of gamma-valerolactone and its derivatives into sustainable and degradable polythioesters through the establishment of the first isomerization-driven ring-opening polymerizations (IROPs) of corresponding thionolactone intermediates. The development of a new cationic initiator [Et3O](+)[B(C6F5)(4)](-) with high activity, exclusive selectivity, living nature, and broad scope of thionolactones is the key to this success. The study also reveals the complete inversion of configuration during IROP of enantiopure gamma-thionovalerolactone and the formation of a highly crystalline supramolecular stereocomplex.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Zhedong Li, Shiwei Duan, Na Zhao, Zhibo Li
Summary: In this study, two bulky phenyl diphosphazene bases, p-PDPB and m-PDPB, were synthesized and used in combination with ureas and squaramides as hydrogen-bond donors to mediate stereocontrolled ring opening polymerization (ROP) of lactide. The phenyl diphosphazene based/urea binary catalytic system successfully synthesized semicrystalline PLAs with narrow dispersity and high tacticity (P-m up to 0.84) in a well-controlled manner. Structural analysis confirmed the linear structure and high end-group fidelity of the resulting polymers, and MALDI-TOF MS analysis indicated the good controllability of the binary catalytic system with minimal transesterification.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Polymer Science
Jie Zhang, Liguo Xu, Wenhao Xiao, Yang Chen, Zhixian Dong, Jinbao Xu, Caihong Lei
Summary: With the increasing focus on health and environmental issues, green chemistry and atomic economy have become important topics for researchers and manufacturers. In this study, squaric acid was used as an organocatalyst to successfully synthesize polyesters with desired molecular weights and narrow dispersity.
EUROPEAN POLYMER JOURNAL
(2021)
Article
Materials Science, Multidisciplinary
Majdi Saleem Naamneh, Philip Lazarovici, Jehoshua Katzhendler
Summary: This study investigated the activity of different organocatalysts and initiators in the ring-opening polymerization of OCAs derived from phenylalanine. It found that dimethylaminoethyl amine and dimethylaminopropyl amine were highly active catalysts for controlled polymerization, while 4-(Hydroxymethyl)-1H-imidazole was the most effective catalyst for uncontrolled polymerization in the presence of 4-DMAP. The study highlights the potential application of Phe-OCA polymers in biomedical materials and provides important implications for the synthesis of polymeric polyesters in translational medicine.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Polymer Science
Zhen-Yu Wang, Guang-Qiang Xu, Li Zhou, Cheng-Dong Lv, Ru-Lin Yang, Bing-Zhe Dong, Qing-Gang Wang
Summary: The isoselective ring-opening polymerization of racemic lactide was achieved by using N-heterocyclic olefin (NHO) with mono(thio)ureas or bis(thio)ureas as catalytic systems. The highest P-m value of 0.91 was observed at -70 degrees C, with high stereoselectivity attributed to chain-end control mechanism.
CHINESE JOURNAL OF POLYMER SCIENCE
(2021)
Article
Polymer Science
Masato Suzuki, Aya Watanabe, Raimu Kawai, Ryo Sato, Shin-ichi Matsuoka, Susumu Kawauchi
Summary: This study reports the ring-opening polymerization of thiolactide, where thiolactic acid undergoes cyclic condensation to form rac-thiolactide, which is then polymerized using a combination of thiol as initiator and DBU as catalyst. The polymerization process was found to be in equilibrium and displayed different structural characteristics and degradability compared to polylactide.
Article
Polymer Science
Jian-Qun Wang, Xian-Hong Wang, You-Hua Tao
Summary: This study successfully synthesized sustainable aliphatic polyamides with controlled features by converting renewable resource 4-hydroxyproline into bicyclic bridged lactam monomers. The resulting polyamides exhibited high molecular weight and low molecular weight distribution, showing potential applications.
CHINESE JOURNAL OF POLYMER SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Yiming Liu, Jizhe Xu, Yiming Zhang, Yong Shen, Zhibo Li
Summary: In this study, the rapid ring-opening polymerization (ROP) of gamma-butyrolactone (γ-BL) using a bisurea and an organophosphazene base as the binary catalyst was presented. Well-defined poly(gamma-butyrolactone) (P gamma BL) samples with various terminal groups were prepared, achieving a moderate monomer conversion of 61% within 10 mins and producing high-molecular-weight P gamma BL with M-n up to 37.5 kDa and good mechanical properties. The use of bisurea as a co-catalyst exhibited higher catalytic activity compared to previous monourea catalysts, significantly reducing the energy cost for the ROP of γ-BL conducted at low temperature condition. This study may overcome obstacles for the scalable production and practical applications of P gamma BL.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Wilfred T. Diment, Charlotte K. Williams
Summary: This article introduces a new catalyst for the ring-opening polymerization of epoxides and anhydrides, which shows high selectivity, fast reaction rates, and good molar mass control. The catalyst produces alpha,omega-hydroxyl telechelic polyesters with high molar masses and monomodal distributions. The high molar mass polyesters exhibit improved mechanical properties compared to medium molar mass samples. The catalyst can also be used to create triblock polyesters with high molar masses by enchainment of different monomers.
Editorial Material
Cardiac & Cardiovascular Systems
Angelo Auricchio
Editorial Material
Biology
David Coates
JOURNAL OF BIOLOGICAL EDUCATION
(2023)
Editorial Material
Education & Educational Research
Colin Foster
INTERNATIONAL JOURNAL OF MATHEMATICAL EDUCATION IN SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Nicholas J. Van Zee, Amanda S. Peroutka, Marc A. Hillmyer, Timothy P. Lodge
Summary: Poloxamers, also known as Pluronics, have been found to alleviate cellular membrane damage, but the underlying protection mechanism is still unclear. This study investigated the impact of poloxamer molar mass, hydrophobicity, and concentration on the mechanical properties of lipid vesicles, revealing that poloxamers tend to decrease the stretching modulus. The study provides important insights into how poloxamers interact with lipid membranes and protect cells from various stresses.
Article
Polymer Science
Aristotelis Zografos, Helena A. All, Alice B. Chang, Marc A. Hillmyer, Frank S. Bates
Summary: A series of model poly((+/-)-lactide) graft copolymers were synthesized and used to study the transition from star-like to bottlebrush structure in shear and extensional flows. Small-amplitude oscillatory shear and extensional rheometry measurements were conducted on samples with different backbone degrees of polymerization. The transition from star-like to bottlebrush structure occurred at a backbone degree of polymerization between 50 and 69. In extensional flows, the star-like melts exhibited no melt strain hardening, while the bottlebrush melts showed prominent strain hardening. These findings are important for designing bottlebrush materials with strain hardening properties for various processing methods involving extensional flows.
Editorial Material
Literature
Raphael Zaehringer
ZEITSCHRIFT FUR ANGLISTIK UND AMERIKANISTIK
(2023)
Editorial Material
Management
[Anonymous]
RISUS-JOURNAL ON INNOVATION AND SUSTAINABILITY
(2023)
Editorial Material
Education, Scientific Disciplines
Javier Diez-Palomar
REDIMAT-REVISTA DE INVESTIGACION EN DIDACTICA DE LAS MATEMATICAS
(2023)
Editorial Material
Humanities, Multidisciplinary
Alexandra Kim, Christine Stevens
COSTUME-THE JOURNAL OF THE COSTUME SOCIETY
(2023)
Editorial Material
Law
Russell Buchan, Emily Crawford, Rain Liivoja
JOURNAL OF INTERNATIONAL HUMANITARIAN LEGAL STUDIES
(2023)
Editorial Material
Religion
Abrahim H. Khan
TORONTO JOURNAL OF THEOLOGY
(2023)
Article
Chemistry, Physical
Leire Sangroniz, Yoon-Jung Jang, Marc A. Hillmyer, Alejandro J. Muller
Summary: The performance of sustainable polymers can be modified and enhanced by incorporating functional groups in the backbone of the polymer chain that increases intermolecular interactions, thus impacting the thermal properties of the material. This study investigates the role of intermolecular interactions on the crystallization of these polymers and proposes a systematic strategy to modify the thermal properties and crystallization kinetics by incorporating functional groups. The results show that the thermal transitions and crystallization kinetics of PEs can be independently tuned by varying their chemical structure.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Polymer Science
Stephanie Liffland, Margaret Kumler, Marc A. Hillmyer
Summary: This study explores the use of star block (ABC)4 terpolymers as high-performance, sustainable aliphatic polyester thermoplastic elastomers. The findings show that the stereocomplexation enhances the thermal stability and resistance to deformation of the material, and the tunable nature of the hard domains significantly impacts the material properties.
Editorial Material
Management
Arnoldo Jose de Hoyos Guevara, Vitoria C. Dib
RISUS-JOURNAL ON INNOVATION AND SUSTAINABILITY
(2023)
Article
Chemistry, Physical
Brenden D. Hoehn, Elizabeth A. Kellstedt, Marc A. Hillmyer
Summary: Porous materials with nanometer-scale pores have important applications as nanoporous membranes. In this study, ABA triblock copolymers were used as precursors to produce nanoporous polymeric membranes (NPMs) in thin film form by degrading the end blocks. Polycyclooctene (PCOE) NPMs with tunable pore sizes were successfully prepared using solvent casting technique. Oxygen plasma etching was employed to improve the surface porosity and hydrophilicity of the membranes. This study provides a straightforward method to produce tough NPMs with high porosity and hydrophilic surface properties.
