Detection of spatial fluctuations of segments in swollen polybutadiene networks by nuclear magnetic resonance pulsed field gradient technique

Abstract

A: 26, 2502 (1984)

Influence of associations on self-diffusion of styrene-methylmethacrylate random copolymers in semidilute acetone solution

“…This rms displacement of 100 nm of the chain segments fluctuating in the network (in one dimension) is in accord with the PFG NMR investigations of radiation crosslinked polybutadiene swollen with benzene, 31 the values measured in aqueous gelatin gels 17 are somewhat smaller. As expected, the transition to the transient network behavior is most clearly observed for the sm 2/8* and sm 1/9 copolymers that have the highest chemical homogeneity and molecular weight.…”

Investigation of translational motion of poly(ethylene glycol) macromolecules in poly(methacrylic acid) hydrogels

“…This feature allows one to differentiate sol and gel components, which gives the possibility to use the PFG NMR method for the study of gel-formation kinetic processes [14][15][16] . Also it was shown 13) that a correlation exists between the value of the effective selfdiffusion coefficient and the cross-link density of the network. All these results give us a hope to succeed in the application of PFG NMR method for the investigation of the processes connected with the complex formation between linear and cross-linked polymers.…”

“…Recently PFG NMR was applied to investigate some simple systems: three-dimensional (3D) networks of radiation crosslinked poly (butadiene) 13) , the hydrogels of gelatine 14) and of cellulose triacetate 15) . The translational mobility was shown to differ both qualitatively and quantitatively from that of linear molecules.…”

“…In refs. 11,12) the processes of interpolymer complex formation were investigated by NMR methods that measured relaxation times and obtained high resolution spectra of the 1 H and 13 C nuclei. At rather high concentrations of PEG (ca.…”

“…Especially strong deviations can be observed for porous systems 19,21) . However, the experimental study of "anomalous" diffusion of radiation cross-linked poly(butadiene) (a chemical gel) 13,16) swollen in deuterated benzene did not reveal any significant deviations of the shape of diffusion decay from the Eq. (2), although a strong dependence of the determined coefficients for poly(butadiene) macromolecules on the diffusion time was observed.…”