Preparation Of Macrocycle Polymers And Multiblock Copolymers Via Diels-Alder "Click" Reaction

Diels-Alder reaction is one of the most important organic reactions. Recently, DA reaction has attracted much attention based on the macromolecular chemistry particularly providing new materials. Tunca and co-workers prepare graft copolymers,ABC type miktoarm star terpolymer,ABC Type Triblock Copolymers,3-Arm Star Polymers (A3),Heteroarm H-shaped terpolymers by the anthracene-maleimide-based Diels-Alder "click" Reaction. This paper described the synthesis of cyclic poly(ε-caprolactone) (PCL). Linear PCL precursors were prepared by ring-opening polymerization (ROP) ofε-caprolactone in bulk, followed by reacting with corresponding acyl chloride containing maleimide end group. The subsequent end-to-end intramolecular coupling reactions were performed under high dilution conditions. The successful transformation of linear PCL precursor to cyclic PCL was confirmed by gel permeation chromatography and ~1H NMR.Cyclic polymers with various chemical structure, composition, molecular characteristics, and architectures are paid steadily increasing attention, because cyclic polymers possess higher density, molecular weight-dependent melt viscosity, higher refractive index, and higher glass transition temperatures as compared to linear polymers. Up to now, only scarce examples of syntheses of cyclic polymers have been reported. This paper also described the synthesis of cyclic copoly(PCL-PDMAEMA) via Diels-Alder "click" reaction.At last this paper described the synthesis of multiblock copolymer via Diels-Alder "click" reaction.