In this study, we developed a metal-free biosynthetic strategy of enzymatic polymerization to fabricate aliphatic poly(pentamethylene carbonate) (PPMC). Novozym-435 lipase showed considerably high catalytic efficiency, and high molecular weights (Mn) of up to 6.0 104 g mol 1 were readily achieved through the ring-opening polymerization of cyclobis(pentamethylene carbonate). The reaction paramet...

Anion exchange membranes (AEMs) find widespread applications as an electrolyte and/or electrode binder in fuel cells, electrodialysis stacks, flow and metal-air batteries, and electrolyzers. AEMs exhibit poor stability in alkaline media; their degradation is induced by the hydroxide ion, a potent nucleophile. We have used 2D NMR techniques to investigate polymer backbone stability (as opposed t...

A charge gradient microscopy (CGM) probe was used to collect surface screening charges on poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] thin films. These charges are naturally formed on unscreened ferroelectric domains in ambient condition. The CGM data were used to map the local electric current originating from the collected surface charges on the poled ferroelectric domains in th...

In recent decades synthetic polymeric materials, because of their unique physical properties, have rapidly replaced more traditional materials such as steel and nonferrous metals, as well as natural polymeric materials such as wood, cotton, and natural rubber. However, one weak aspect of synthetic polymeric materials compared with steel and other metals is that these materials are combustible u...

The enzymatic degradability of poly(vinyl acetate) was investigated in toluene solutions at various temperatures with hog pancreas lipase. The polymer degraded by specific scission to yield oligomeric products with a molecular weight of 700. Continuous distribution kinetics were used to determine the rate coefficients. The variation of the rate coefficients with the temperature indicated an opt...

We report the enzymatic degradation mechanism of a solution-grown poly[(R)-3-hydroxybutyrate] (P(3HB)) single crystal with an extracellular polyhydroxybutyrate depolymerase purified from Alcaligenes faecalis T1 (PhaZAfa). The P(3HB) single crystals adsorbed on highly ordered pyrolytic graphite were incubated with a wild-type or a hydrolytic-activity-disrupted mutant of PhaZAfa, and morphologica...

Logic gate nanoparticles, where two chemical transformations take place one after the other, were successfully formulated from a newly synthesized random co-polymer. This polymer, poly([2,2'-(propane-2,2-diylbis(oxy))bis(ethane-2,1-diyl) diacrylate ]-co-[hexane-1,6-diyl diacrylate]-4,4' trimethylene dipiperidine), (poly-β-aminoester ketal-2) contains two pH responsive moieties within its backbo...

Depolymerizing lignin, the complex phenolic polymer fortifying plant cell walls, is an essential but challenging starting point for the lignocellulosics industries. The variety of ether- and carbon-carbon interunit linkages produced via radical coupling during lignification limit chemical and biological depolymerization efficiency. In an ancient fungus-cultivating termite system, we reveal unpr...

The enhanced thermal stability of polymer-clay nanocomposites over the original polymers is one of their most interesting features and it has been profusely studied within the last decades. Here, a thorough kinetic analysis of polystyrene and a montmorillonite-polystyrene nanocomposite has been performed making use of state-of-the-art kinetic procedures. It has been found that the degradation m...

Polymer matrix composites can be severely degraded/damaged under thermal loading caused by fire. Fire degradation of fiber composites is a serious concern in large load-bearing structural applications such as ship, piers and bridges. This paper describes results from combined experimental and theoretical studies of compressive failures of polymer-matrix glass-reinforced composites which have un...