JM methanol technology chosen for largest single train methanol plant in the world

Abstract

Hydrogels with interpenetrating polymer network (IPN) show distinct advantages including enhanced mechanical properties and multiple functions. In this work, we prepared a series of dendronized IPN hydrogels by cryogelation technique using reversible Schiff-base crosslinked oligoethylene glycol (OEG)-based dendronized polymers to form one network, and covalent crosslinked polyacrylamide (PAAm) to form another network. These cryogels not only exhibit high mechanical strength with interconnected porous morphology, but also inherit characteristic thermoresponsive property from OEG-based dendronized polymers, and show thermally induced deswelling behavior upon heating to above their phase transition temperatures. Thermally induced reversible dehydration/rehydration of the OEG-based dendronized polymers and pH-mediated reversible formation of dynamic Schiff-base linkages afford the IPN cryogels amazingly dual-shape memory capability. Effects of polymer composition and fabrication method (one-pot/two-steps) on porous structures, responsive behavior, as well as mechanical properties of these dendronized IPN cryogels were investigated in details. We believe present work provides a convenient strategy to fabricate novel smart hydrogels with unique thermoresponsive and adaptive features, which could act as promising scaffolds for bio- or actuator applications.