Study of branched oligoesters and crosslinked polyurethane elastomer by the NMR method

Structural Dynamic Analysis of Polymer Blends Containing Additives of Polyurethane Nature in Different Phase Aggregate States

“…Comparison of the nature of the behaviour of all relaxation parameters (T 1i , T 2i , P 1i , P 2i ) of model blends containing an oligomer and PPF ( Figure 2) indicates that the obtained results cannot be attributed to the presence only of physical interactions with the participation of polymer additives. Therefore, the observed relationships indicate the possibility of the chemical interaction of the liquid oligomer additive with polymer components of the composites, and on the whole can correspond to increase in the degree of branching of the macromolecules [13] with simultaneous strengthening of the short-range conformational order. The latter, in a constant-volume condensed medium, should be accompanied with a redistribution (or may be realised in the course of redistribution) of the free volume.…”

Plasticizer effect on network structure and hydrolytic degradation

“…-increases of relaxation times T 1 and T 2 when temperature (and mobility) increases [30], -increases of stretched exponential relaxation times for elastomers with various crosslinking degrees at a fixed temperature [31].…”

Influence of the Nature of the Cyclic Component in the Composition of Ternary Ethylene–Propylene Rubber on the Structural and Dynamic State of Blends with Chlorosulphonated Polyethylene

“…Consequently, the structure and dynamics of SKEPT macromolecules depend considerably on the structure of the cyclic fragment capable of fulfilling the function of a branching agent (under the fairly severe conditions of preparation of blended composites) and/or of a relatively rigid block influencing the conformational behaviour of the macrochains in the blends. Previously established behaviour patterns of change in the relaxation parameters as a function of the type and number of flexible-chain branches of oligomeric length [7] enable us to assume that the packing of the polymer chains in composites with DCPD, irrespective of scale, is less dense and homogeneous than in systems with ENB. As the molecular weight, MWD, and T 1 [6] of the individual polymers of SKEPT with different blocks C are roughly identical, the observed features of the structural dynamic behaviour of blends can be attributed to the presence in the macromolecules of SKEPT containing ENB of mainly short-chain branches or of side groups symmetrical in shape and size, and also polymer chain conformations similar to them in terms of structural dynamic properties (for example, the internal rotation potential barrier, and so on).…”