In a paper published in Polymer Science & Technology, an international team of scientists

explores an effective protocol for toughening vitrimers based on dioxaborolane metathesis through introducing a reversible secondary interaction and revealed the underlying molecular mechanism of this protocol. They copolymerized hexyl methacrylate with hydrogen-bonding n-isopropyl methacrylamide and vitrimeric cross-linkers to prepare dual-cross-linked networks. They found the breakup of the hydrogen bonds during the elongation significantly dissipated the energy, leading to the softening of the materials, thereby facilitating the stretch to high strain. Then the Dobrynin model modified by Konkolewicz and co-workers upon including a strain rate-dependent element was used to capture the softening process. The deviation at a high content of hydrogen bonds was attributed to the coupled motion of the hydrogen bonds where the distance between hydrogen bonds becomes smaller than the Kuhn length. Modification of the model according to this change is considered an interesting future work. This study is led by Shilong Wu and Quan Chen (State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China).

In a paper published in Polymer Science & Technology, an international team of scientists

designed and synthesized tetracoordinate aluminum methyl complexes bearing (amidoalkyl)pyridine−phenolate (AmPyPh) pincers for industrial _L-LA polymerizations. Then they further investigated the electronic and steric effects of the substituents in different positions on catalytic activity with assistance of density functional theory calculation. The results indicated the synthesized AmPyPh-Al catalysts exhibited excellent thermostability as well as good protonic tolerance, which could effectively promote the polymerization of technical grade _L-LA without further purification under industrial-relevant conditions (150−180 °C, in melt and bulk) with catalyst concentrations as low as 0.0005 mol % (monomer/catalyst feed ratio = 200000:1). Meanwhile, these novel Al complexes could suppress the epimerization side reaction under harsh conditions and afforded semicrystalline PLLA. This study is led by Xiaosa Zhang (College of Science, Shenyang University of Chemical Technology, Shenyang 110142, China) and Bin Wang (Tianjin Key Laboratory of Composite & Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China).

An Osaka Metropolitan University researcher conducted a survey on the use of private wells during the 2018 Western Japan floods in Kure City, Hiroshima Prefecture, which was affected by water supply disruptions.