Multiblock Copolymers of Norbornene and Cyclododecene: Chain Structure and Properties

Abstract

We investigate the structure–property relations of the multiblock copolymers of norbornene with cyclododecene synthesized via the macromolecular cross-metathesis reaction between amorphous polynorbornene and semicrystalline polydodecenamer in the presence of the first-generation Grubbs catalyst. By adjusting the reaction time, catalyst amount, and composition of the initial system, we obtain a set of statistical multiblock copolymers that differ in the composition and average length of norbornene and dodecenylene unit sequences. Structural, thermal, and mechanical characterization of the copolymers with NMR, XRD, DSC (including thermal fractionation by successive self-nucleation and annealing), and rotational rheology allows us to relate the reaction conditions to the average length of crystallizable unit sequences, thicknesses of corresponding lamellas, and temperatures of their melting. We demonstrate that isolated dodecenylene units can be incorporated into crystalline lamellas so that even nearly random copolymers should retain crystallinity. Weak high-temperature endotherms observed in the multiblock copolymers of norbornene with cyclododecene and other cycloolefins could indicate that the corresponding systems are microphase-separated in the melt state.

Effect of Chain Structure on the Various Properties of the Copolymers of Fluorinated Norbornenes with Cyclooctene

“…Qualitatively similar conclusions on the influence of the distribution of comonomer units on polymer crystallinity were previously made by Pitet et al [58] for the copolymers of COE with phenylcyclooctene and by us [65] for the copolymer of cyclododecene with norbornene.…”

New Technology for Production of Dicyclopentadiene and Methyl-Dicyklopentadiene

“…CPD is developed in situ by the decomposition of DCPD. The most commonly commercially produced is ethylidene norbornene [11,12], which is produced by reacting CPD with 1,3-butadiene and is used as the preferred thermonomer for the production of EPDM elastomer [13]. With the continuing development of copolymers of olefins with cycloolefins, norbornenes find more significant applications in modifying the properties of these new and interesting polymers.…”

Thermal Fractionation of Polyolefins: Brief History, New Developments and Future Perspective

“…polymers, and we are finding them in more research on new materials, including other polyolefins [33][34][35][36][37], composites [38][39][40][41][42][43] and even some emerging polymers or special block copolymers [71][72][73][74][75][76], for which, a series of polymer synthesis factors such as catalytic system and polymerization method, materials with different molecular chain structures will be formed. Polymer chemists used these fractionation methods to evaluate the quality of synthesis scheme, and polymer physicists paid more attention to the physical behavior caused by chain structure changes.…”