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Spin-lattice relaxation time blends

Fig. 13. Spin-lattice relaxation times of PS(OH) and PS(OH)/PMMA as functions of the hydroxyl content in PS(OH). for different protons attached to different carbons in pure PS(OH). A and O for different protons in PS(OH) and PMMA in the blends, respectively. Thin horizontal line for pure PMMA as a reference [111]... Fig. 13. Spin-lattice relaxation times of PS(OH) and PS(OH)/PMMA as functions of the hydroxyl content in PS(OH). for different protons attached to different carbons in pure PS(OH). A and O for different protons in PS(OH) and PMMA in the blends, respectively. Thin horizontal line for pure PMMA as a reference [111]...
As an NMR methodology for elucidating miscibility in the PLA/PLV, PLA/PLIL, PDA/PLV and PG/PLV blends, the proton spin-lattice relaxation times in the rotating frame ) for homopolypeptides and their... [Pg.27]

Figure 11. Variation of spin lattice relaxation time and spin concentration for carbonization of blends of two petroleum pitches (See Ref. 70). Figure 11. Variation of spin lattice relaxation time and spin concentration for carbonization of blends of two petroleum pitches (See Ref. 70).
Chang et al. reported the miscibility of poly(vinylphenol) (PVPh) with poly(methyl methacrylate) (I MMA) Figure 1 shows the C CP/MAS spectra of pure PVPh, PMMA, PVPh-co-PMMA, PEG, and PVPh-co-PMMA/ poly(ethylene oxide) (PEO) blends of various compositions with peak assignments. VPh contents of PVPh-co-PMMA is 51 mol% and Mn of PEO is 20,000. The spin lattice relaxation time in the rotating frame (Tip ) was measured to examine the homogeneity of PVPh-co-PMMA/PEO blends on the molecular scale. [Pg.168]

The miscibility of poly(methyl acrylate) (PMAA, Mw= 150,000)/PVAc (Mw= 167,000) blends at various mixing ratios was investigated by both Ti and Tip measurements. C CP/MAS NMR spectra of PMAA, PVAc and the PMAA/PVAc blends are shown in Fig. 2. Figure 3 shows the plots of the spin-lattice relaxation times in the laboratory (Ti , A) and in the rotating (Ti, B) frames against the molar ratio of PMAA (xpmaa)-The ll relaxation times from the CI 12 (O) and OCH (A) carbons for PMAA and PVAc, respectively, can be observed because these two carbons are observed separately even in the blends (Fig. 2), so that it is possible to obtain each relaxation time for PMAA or PVAc in the blends independently. [Pg.170]

Fig- 3. Observed spin-lattice relaxation times in the laboratory (Ti, A) and in the rotating B) frames against the molar unit ratio of PMAA/PVAc blends... [Pg.172]

The rotating-frame spin-lattice relaxation time for protons, Tip,( H), was measured indirectly from CPMAS/DD NMR to probe possible molecular scales of heterogeneity in the miscible poly(benzyl methacrylate)/poly(ethylene oxide) blend over the whole composition range. ... [Pg.261]

The blending effects on motion have also been studied by measuring the spin-lattice relaxation time T. Feng et al. [70] measured Ti of PPO and PS in PPO/PS. They showed that the respective values for the... [Pg.366]

The domain size of PVA/P(3HB) blend systems was studied by observing the spin-lattice relaxation time, Ti, by the CPMAS NMR technique [126]. [Pg.810]

Two-component systems have received some attention. - Poly(vinyl-idene fluoride>-poly(methyl or ethyl methacrylate)s blends have been mentioned in the previous section. A study of compatibility in blends of poly(vinyl chloride) and ethylene-vinyl acetate copolymer (EVA) has been reported. Spin-lattice relaxation time measurements were bi-exponential corresponding to rigid [poly(vinyl chloride)] and mobile (EVA) phases. A precipitated mixture showed intermingling of EVA in the poly(vinyl chloride) phase, but phase separation occurred on heating. Cashell et a/. have contributed a short note on the effects of magnetic susceptibility inhomogeneities of lincwidths in carbon black-filled... [Pg.243]

A quantitative analysis of the mixing scale in the PACMO/CA (DS = 2.18) blends was carried out through measurements of proton spin-lattice relaxation times in the rotating frame (T ). values can be obtained by practically fitting the decaying carbon resonance intensity to the following single-exponential function ... [Pg.683]

The combining NMR techniques in the solid state permit the evaluation of the polymeric systems homogeneity. In polycarbonate-polyvinyl pyrrolidone blends, the response of proton spin-lattice relaxation time in the rotating frame was the determinant to obtain information on the transition when the quantity of polyvinyl pyrrolidone is close to 40 wt% and a better organisation of amorphous phase was detected. 13 refs. [Pg.119]

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Blending time

Relaxation times spin-lattice

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Spin-lattice relaxation

Spin-relaxation times

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