Integrated analysis of solid-state NMR spectra and nuclear magnetic relaxation times for the phenol formaldehyde (PF) resin impregnation process into soft wood

Nishida, Masakazu; Tanaka, Tomoko; Miki, Tsunehisa; Hayakawa, Yoshio; Kanayama, Kozo

doi:10.1039/c7ra11295e

Cited by 21 publications

(11 citation statements)

References 27 publications

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“…Therefore, the plasticization with the flexible PBS enhanced slow molecular motions (kHz) corresponding to the spin-locking frequency more than did PLA. We previously discussed the correlation of increase of the PST-MAS signals and T 1 ρ H values for phenol formaldehyde resin-impregnated soft wood [25]. Similar to this previous result, the increases of the 13 C PST-MAS NMR signals here could be explained by the enhancement of slow molecular motions (kHz) due to the plasticization with PBS.…”

Section: Resultssupporting

confidence: 86%

Solid-State Nuclear Magnetic Resonance (NMR) and Nuclear Magnetic Relaxation Time Analyses of Molecular Mobility and Compatibility of Plasticized Polyhydroxyalkanoates (PHA) Copolymers

et al. 2018

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The molecular mobility and compatibility of plasticized polyhydroxyalkanoates (PHA) were investigated, focusing on changes due to copolymerization using either flexible poly (butylene succinate) (PBS) or rigid poly(lactic acid) (PLA) units. For the case of a poly(3-hydroxybutyrate) (PHB) unit in plasticized PHA, copolymerization of either PBS or PLA decreased 1H and 13C spin-lattice relaxation times in the laboratory frame (T1H and T1C) in the same manner, while PBS produced a lower 1H spin-lattice relaxation time in the rotating frame (T1ρH) than PLA. Both the signals of 1H MAS (magic-angle spinning) and 13C PST (pulse saturation transfer) MAS nuclear magnetic resonance (NMR) spectra were sharpened and increased by copolymerization with PBS. A variable temperature relaxation time analysis showed that the decrease of T1H values was dominated by the 1H spin diffusion via the interface between PHB and the added polyester because of the good compatibility. Meanwhile, the decrease of T1C values was dominated by increasingly rapid molecular motions of PHB because of the lowered crystallinity due to the plasticization. Slow molecular motions (kHz order) were enhanced more by the addition of PBS than PLA, although rapid molecular motions (MHz order) were enhanced by either polyester. Several NMR parameters were beneficial for analyzing the manufacturing process as the indexes of polymer compatibility and molecular motions.

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Section: Resultssupporting

confidence: 86%

Solid-State Nuclear Magnetic Resonance (NMR) and Nuclear Magnetic Relaxation Time Analyses of Molecular Mobility and Compatibility of Plasticized Polyhydroxyalkanoates (PHA) Copolymers

et al. 2018

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“…Since the T 1 C values of all substituents except CH 3 group decreased with increasing temperature, the molecular motions connected with these T 1 C values are associated with the long correlation time region (s c u 0 [ 1). 29 Therefore, for the components in plasticized PHA/PCL blends, the increase of T 1 C equates to a decrease of molecular mobility of a MHz order, which matches with the Larmor frequency of 13 C nuclei. The T 1 C changes associated with blending with 50% PCL show that the sea-island morphology in plasticized PHA/PCL blends considerably decreased the molecular mobility of PCL.…”

Section: Spin-lattice Relaxation In the Laboratory Frame Of Plasticizmentioning

confidence: 68%

“…For example, water molecules had a narrower line width because of a longer T 2 (greater molecular mobility) while biomass constituents in so wood showed a wider line shape because of shorter T 2 (less molecular mobility). 29 Here, the molecular mobility involved in T 2 relaxation could be monitored by 1 H MAS NMR spectra of plasticized PHA/PCL blends.…”

Section: Resultsmentioning

confidence: 99%

Multi-scale instrumental analyses of plasticized polyhydroxyalkanoates (PHA) blended with polycaprolactone (PCL) and the effects of crosslinkers and graft copolymers

et al. 2019

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“…For example, we have examined the effects of manufacturing processes on PLA composites using a reactive extrusion machine and nuclear magnetic relaxation time analysis; to date, we have investigated PLA nanocomposites with organic montmorillonites [ 31 ] and PLA/poly(ε-caprolactone) (PCL) random copolymers [ 32 ]. Furthermore, we have also studied the molecular dynamics of biomass constituents in woody and herbaceous materials interacting with water molecules, using solid-state NMR spectra and nuclear magnetic relaxation times [ 33 , 34 , 35 ].…”

Section: Introductionmentioning

confidence: 99%

Nucleating and Plasticization Effects in Drawn Poly(Lactic Acid) Fiber during Accelerated Weathering Degradation

Nishida

Tanaka

Tanaka³

et al. 2018

Polymers

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Changes in the polymer properties of poly(lactic acid) (PLA) fibers during drawing and degradation processes were analyzed using solid-state NMR, with the goal of elucidating morphological changes that influence fiber tensile properties. Combination of X-ray diffraction (XRD) and differential scanning calorimeter (DSC) indicated that the drawn PLA fibers consisted of different proportions of α crystalline and amorphous forms. 13C CP-MAS NMR spectra showed amorphous-like broad singlet signals, of which the full width at half maximum (FWHM) decreased with increasing crystallinity and crystal orientation. The T1H value decreased by interaction with additives and increased with increasing crystal orientation. The interaction with additives also reduced T1C values, which increased with increasing crystallinity. Use of organic clay enhanced the crystallization of high draw-ratio PLA fibers due to nucleation, which increased tensile strength; this effect gradually decreased with time during accelerated weathering. In contrast, the plasticization due to the addition of flexible polymers increased fiber elongation, which rapidly dropped during the degradation. Changes of FWHM, T1H, and T1C values indicated that the degradation occurred at sites within the amorphous portions of the PLA fibers containing organic clay, while the flexible polymers were preferentially degraded if they were present in the PLA fibers.

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Integrated analysis of solid-state NMR spectra and nuclear magnetic relaxation times for the phenol formaldehyde (PF) resin impregnation process into soft wood

Abstract: Integrated analysis using a solid-state NMR method revealed that PF resin permeated not only lignin but also carbohydrate polymers.

Cited by 21 publications

References 27 publications

Solid-State Nuclear Magnetic Resonance (NMR) and Nuclear Magnetic Relaxation Time Analyses of Molecular Mobility and Compatibility of Plasticized Polyhydroxyalkanoates (PHA) Copolymers

Solid-State Nuclear Magnetic Resonance (NMR) and Nuclear Magnetic Relaxation Time Analyses of Molecular Mobility and Compatibility of Plasticized Polyhydroxyalkanoates (PHA) Copolymers

Multi-scale instrumental analyses of plasticized polyhydroxyalkanoates (PHA) blended with polycaprolactone (PCL) and the effects of crosslinkers and graft copolymers

Nucleating and Plasticization Effects in Drawn Poly(Lactic Acid) Fiber during Accelerated Weathering Degradation

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