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The side chain motion and structure of the racemic mixture of poly(γ-benzyl glutamate) (PBDLG) in the solid state were studied by means of the cross polarization/magic angle spinning (CP/MAS) 13C NMR. Cβ and Cγ regions of NMR spectra for PBDLG in the stacked state of phenyl rings exhibit a remarkable difference from those for poly(γ-benzyl L-glutamate) (PBLG) with no side chain stacking. Use of γ-d2 PBDLG, deuterated at Cγ, showed that the upfield shift occurs in a part of γ-carbons. It was suggested that this new peak arises from the regular side chain conformation with phenyl ring stacking. The measurements of 13C T1ρ, spin-lattice relaxation time in the rotating frame, indicated that both the side chain and main chain motions are restricted in the stacked state. However, it is noticeable that such effect of stacking is especially remarkable for Cγ rather than phenyl ring. This means that phenyl rings have a rather high mobility even in the staked state.

Side Chain Dynamics in Poly(γ-benzyl L -glutamate) as Studied by High-Resolution Solid State 13 C Nuclear Magnetic Relaxation in Rotating Frame

Side Chain Motion of Poly( L -glutamate)s Having Long Alkyl Side Chains as Studied by Spin-Probe Technique

Molecular Motion of Poly(acrylate)s Having Mesogenic Side Chains in Deuterated Chloroform Solution Studied by High-Resolution 13 C Nuclear Magnetic Resonance

Differential thermal analysis of a ultra-high molecular weight polyethylene (UHMW-PE, Mv; 2.7×106) crystallized from a 0.1 wt% decalin solution was performed at pressures from about atmospheric pressure to 600 MPa. In the high pressure region such as 600 PMa, thick lamellae similar to extended-chain crystal are formed very rapidly in the heating process. The rapid lamellar thicknening is suggested to be due to the decrease of enthanglements. Its phase diagram was determined. The triple point in the phase diagram was about 370 MPa. The high pressure phase region of the solution crystallized sample is between those of as-polymerized powder sample and bulk sample which is melt-crystallized one after kneading in the melt. The change of phase diagram among those samples may be due to differences in entanglement density.

Phase Separation Process in Polymer Systems III. Spinodal Decomposition in the Critical Mixture of Polystyrene and Poly(methylphenylsiloxane) and Scaling Analysis