Article
Chemistry, Multidisciplinary
Xiaoxian Lu, Xun Zhang, Chengjian Zhang, Xinghong Zhang
Summary: The alternating copolymerization of cyclic anhydride and o-phthalaldehyde is reported for the synthesis of cyclic and recyclable polyesters. The method is efficient and utilizes common catalysts at room temperature, producing high yields within a short time. The resulting polyesters have well-defined alternating sequences and high-purity cyclic topology, and can be easily recycled to their monomers through chemical reactions.
Article
Polymer Science
Chong-Min Chen, Xiaowei Xu, He-Yuan Ji, Bin Wang, Li Pan, Yi Luo, Yue-Sheng Li
Summary: In this study, the ring-opening alternating copolymerization of cyclic anhydride and epoxide was thoroughly investigated using alkali metal carboxylates as initiators. The coordination effects of epoxide on the alkali metal carboxylate were verified using FT-IR spectroscopy and DFT calculations. Alkali metal carboxylates were found to effectively catalyze the copolymerization of cyclic anhydride and epoxide, leading to the synthesis of polyesters with alternating structures. The use of potassium acetate was particularly noteworthy as it allowed for the copolymerization of different cyclic anhydrides and epoxides, including the high molar feed ratio synthesis of poly(PA-alt-PO) with a molecular weight exceeding 100 kDa.
Article
Chemistry, Multidisciplinary
Mani Sengoden, Gulzar A. Bhat, Donald J. Darensbourg
Summary: Recent years have seen significant research efforts in the development of metal-free organocatalysts for coupling reactions of CO2 and epoxides. In this study, a series of boron-phosphonium organocatalysts were synthesized and characterized for catalyzing these reactions. The catalysts exhibited high selectivity and were found to be less hygroscopic compared to metal-based catalysts. They successfully facilitated the copolymerization of CO2 and epoxides to form polycarbonates.
Article
Polymer Science
Guofei Feng, Ximin Feng, Xiong Liu, Wenqi Guo, Chengjian Zhang, Xinghong Zhang
Summary: This article introduces a method to convert the pollutant CS2 into valuable sulfur-containing polymers using a cooperative organocatalyst system. The copolymerization reaction is highly efficient, avoids small-molecule byproducts, and produces polythiocarbonates with highly regular sequences. The polythiocarbonates demonstrate desirable thermal and mechanical properties.
Article
Polymer Science
Keisuke Hayashi, Arihiro Kanazawa, Sadahito Aoshima
Summary: This study presents a novel approach using o-phthalaldehyde (OPA) as a comonomer to enable the cationic copolymerization of various bulky enol ethers that are difficult to homopolymerize and/or copolymerize. The relationships between the structures of the enol ethers and the copolymerization behavior were investigated, revealing that monomers with methyl and/or primary alkyl groups can undergo alternating copolymerization with OPA.
Article
Materials Science, Multidisciplinary
V Sethuraman, T. M. Sridhar, G. Vimala, R. Sasikumar
Summary: This article presents the synthesis of copolymers of o-anisidine and ethyl 4-aminobenzoate through chemical polymerization, followed by spectroelectrochemical analysis and dopamine sensing tests.
Article
Chemistry, Physical
Max Hirschmann, Rachele Zunino, Sara Meninno, Laura Falivene, Tiziana Fuoco
Summary: In this study, bi-functional organocatalysts containing a (thio-)urea moiety and an iminophosphorane moiety were synthesized and optimized for the ring-opening alternating co-polymerization of phthalic anhydride with three different epoxides. The most effective catalyst showed quantitative conversion of all tested epoxides within 24 hours, with high ester-selectivities up to >97%. NMR and DFT experiments revealed that the catalysts existed as dimers in solution and dissociated during the initiation of polymerization. The catalyst coordinated to the growing chain and modulated its reactivity through reversible protonation/deprotonation, suppressing transesterification side reactions even at prolonged polymerization times without the need for a co-catalyst. The rate-determining step of the polymerization was the ring-opening of the epoxide by the carboxylate chain end, and higher temperatures and concentrations of epoxide and catalyst promoted polymerization rates.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Inorganic & Nuclear
Ye Liu, Shi-Huan Li, Shi-Yu Chen, Xiao-Bing Lu
Summary: In this study, propylene was successfully incorporated into an ethylene/CO copolymer chain using a cost-effective nickel catalyst. The electronic and steric effect of different moieties in the catalyst was systematically investigated for terpolymerization. It was observed that the melting temperature (Tm) of the resulting polyketones was proportional to the amount of propylene incorporated into the polymer chain, without significant impact on the degradation temperature. The PNPO catalysts showed higher preference for propylene consumption compared to dppp-type catalysts, which is important for efficient utilization of alpha-olefin resources.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Quanyou Yao, Yongjie Chen, Yaorong Wang, Dan Yuan, Hongpeng You, Yingming Yao
Summary: A series of rare-earth metal complexes stabilized by tris(phenolate) ligands were synthesized and applied in the copolymerization of CO2 and cyclohexene oxide. The addition of benzyl alcohol improved the polymerization yields and selectivity. The reaction between benzyl alcohol and the rare-earth metal complexes resulted in the formation of dinuclear complexes.
JOURNAL OF RARE EARTHS
(2022)
Article
Polymer Science
Hongyan Xie, Lanlan Zheng, Jiabing Feng, Xinyu Wang, Suping Kuang, Li Zhou, Jia Jiang, Yaling Xu, Yan Zhao, Zhiguang Xu
Summary: Ring-opening alternating copolymerization (ROAC) using alkali metal carbonates (AMCs) as efficient and environmentally benign catalysts is reported. The ROAC of phthalate anhydride (PA) and propylene oxide (PO) is catalyzed efficiently by AMC at 100 degrees C, producing polyesters with perfectly alternating structures. The structural and functional diversity of the resultant polyesters can be expanded by using various epoxide monomers and alcohol initiators. The cooperative catalysis of AMC accelerates the generation of the alternating structure.
Review
Polymer Science
Tian-Jun Yue, Li-Yang Wang, Wei-Min Ren
Summary: The incorporation of sulfur atoms into polymer main chains can enhance properties such as mechanical strength, optical properties, thermal properties, and adhesive abilities. This makes sulfur-containing polymers promising materials, but challenges such as mixed structures and weak stereochemistry control need to be addressed for precise synthesis.
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.
Article
Polymer Science
Keisuke Hayashi, Arihiro Kanazawa, Sadahito Aoshima
Summary: The cationic copolymerization ofo-phthalaldehyde with various styrene derivatives and vinyl ethers was investigated, with a focus on the relationship between the structure and reactivity of vinyl monomers and the copolymerization behavior. The existence of alpha or beta-substituents on the vinyl group was found to be essential for efficient crossover reactions with styrene derivatives, while various vinyl ethers underwent copolymerization with o-phthalaldehyde. The use of vinyl monomers with both large steric hindrance and highly reactive beta-carbon was effective in achieving an alternating-like copolymerization. Additionally, degradable copolymers were successfully obtained from styrene derivatives.
Article
Polymer Science
Jiaxin Liang, Shuxian Ye, Siyuan Wang, Shuanjin Wang, Dongmei Han, Sheng Huang, Zhiheng Huang, Wei Liu, Min Xiao, Luyi Sun, Yuezhong Meng
Summary: The copolymerization of epoxides and carbon dioxide with cyclic anhydrides provides a facile route to obtain biodegradable polymers with diverse structures. Metal-free Lewis acid-base pairs, such as triethylborane (TEB) and triethylamine (TEA), exhibit high catalytic activity in the reaction. The properties and structures of the copolymers can be adjusted by using different reactants.
Article
Polymer Science
Taylor B. Young, Owaen G. Guppy, Alysia J. Draper, Joshua M. Whitington, Benson M. Kariuki, Alison Paul, Mark Eaton, Simon J. A. Pope, Benjamin D. Ward
Summary: Polymers often lack the properties required for their intended applications. Additives such as plasticizers, flame retardants, stabilizers, and colorants are used to modify their physical properties to suit the final product. However, colorants pose challenges for recycling technologies as they cannot be removed through reprocessing. The authors have developed a method to prepare colored polymers by adding chromophore monomers to copolymerization reactions, achieving highly colored materials with minimal changes in properties from the base polymer. They have also successfully depolymerized the colored polymers and reformed them into colorless polymers, paving the way for recyclable polymers with tunable properties through the use of dopant-level monomers.
