Synthesis and Functionalization of ROMP-Based Gradient Copolymers of 5-Substituted Norbornenes

Abstract

Gradient copolymers of exo-5-(benzyloxy)norbornene and exo-5- [(4-tert-butyl)benzyloxy]norbornene were synthesized via ring-opening metathesis polymerization (ROMP). Kinetic studies revealed that the reactivity ratios of both monomers were close to unity. As predicted, this monomer pair did not result in copolymers with significant gradients under batch polymerization conditions. However, semibatch conditions resulted in copolymers with sizable gradients whose shape was independent of the rate of addition. Addition of the monomers simultaneously via a dual and opposite ramping strategy led to a 50/50 copolymer with an exceptionally linear gradient. These gradient copolymers were further functionalized via hydrogenation, bromination, and bromoalkoxylation.

Amphiphilic gradient copolymer of [poly(ethylene glycol) methyl ether] methacrylate and styrene via atom transfer radical polymerization

“…4,6,[8][9][10][11][12][13][22][23][24] Gradient copolymers have also been synthesized using other living or pseudo-living polymerization methods such as ring-opening metathesis polymerization 7,14,25 and cationic polymerization. 26 The simple synthetic procedures involved give gradient copolymers a major advantage over block copolymers.…”

Chain‐by‐Chain Monte Carlo Simulation: A Novel Hybrid Method for Modeling Polymerization. Part I. Linear Controlled Radical Polymerization Systems

“…A specific composition profile is best achieved by charging the full amount of slow monomer together with desired initial amount of fast monomer and feeding the fast monomer as reaction proceeds . Although the most common and convenient way is to constantly feed the fast monomer, copolymer composition profiles are expected to be better controlled by programed feeding policies . Figure is the volumetric feed rate values calculated and updated in a programed manner for achieving the hyperbolic gradient profile given by Equation using MOM and Figures and are the corresponding F ins,MMA and F cum profiles, respectively, as a function of NACL predicted by MOM and CBC‐MC method for 10 3 , 10 4 , and 10 5 chains for this feeding policy.…”

Synthesis of reactive poly(norbornene): Ring‐opening metathesis polymerization of norbornene monomer bearing cyclic dithiocarbonate moiety

“…Within 20 min, BNB was completely consumed, while the conversion of NB‐DTC at 20 min was 70%. From these copolymerization behaviors, formation of segments rich in BNB‐derived unit in the early stages and that of segments rich in NB‐DTC‐derived unit in the late stages to give a gradient copolymer can be assumed 13. In fact, after the complete consumption of BNB, formation of insoluble polymer by homopolymerization of NB‐DTC was not observed, implying that NB‐DTC molecules consumed after 20 min until 90 min were successfully converted into homo‐sequences of NB‐DTC into the tails of the gradient copolymers.…”