Multiblock Copolymers of Norbornene and Cyclododecene: Chain Structure and Properties

• Published in: Polymers Vol. 13; no. 11; p. 1756
• Main Authors: Denisova, Yulia I, Shandryuk, Georgiy A, Arinina, Marianna P, Levin, Ivan S, Zhigarev, Vsevolod A, Gringolts, Maria L, Finkelshtein, Eugene Sh, Malkin, Alexander Ya, Kudryavtsev, Yaroslav V
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 27.05.2021; MDPI
• Subjects: Annealing; Catalysts; Composition; Copolymers; Crystal structure; Crystallinity; Ethanol; Fractionation; High temperature; macromolecular cross-metathesis; Mechanical properties; Metathesis; multiblock copolymer; NMR; Nuclear magnetic resonance; Nucleation; Polymerization; Polymers; Polynorbornene; Reaction time; Rheological properties; Rheology; Structural analysis; thermal fractionation; Thermodynamic properties; United States > US; multiblock copolymer; thermal fractionation; crystallinity; macromolecular cross-metathesis
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym13111756

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.