A collection of solid-state13C CP/MAS NMR spectra of common polymers

Wilhelm, Manfred; Neidhöfer, Michael; Spiegel, Stefan; Spieß, Hans Wolfgang

doi:10.1002/(sici)1521-3935(19991001)200:10<2205::aid-macp2205>3.0.co;2-6

Cited by 28 publications

(24 citation statements)

References 13 publications

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“…The typical molecular structure of PLA‐PUs is confirmed from the solid‐state 13 C‐CP/MAS NMR spectrum of MLB1000‐2 (Fig. ) of the MDI series of PUs, which is consistent with previous reports . The broad peak at 171.17–170.12 ppm is due to the carbonyl carbons of the carboxylate and ester groups.…”

Section: Resultssupporting

confidence: 90%

Synthesis of poly(lactic acid)‐based polyurethanes

Chen

Tsao

Chou

et al. 2012

Polymer International

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Poly(lactic acid) (PLA) is a biodegradable aliphatic polyester, but its brittleness makes it unsuitable for many packaging and appliance applications. The goal of the work reported was to create novel poly(ester urethane)s that incorporate biodegradable poly(lactic acid) diols (PLA‐OHs) and good mechanical properties of increased molecular weight via crosslinked network formation for engineering plastics applications. Three kinds of polyols (PLA‐OHs, PLA‐OHs/poly(tetramethylene ether) glycol or PLA‐OHs/poly(butylene adipate) glycol (PBA)) and two kinds of diisocyanates (4,4‐diphenylmethane diisocyanate (MDI) or toluene 2,4‐diisocyanate (TDI)) were chosen for the soft and hard segments to compare their mechanical properties. In addition, 1,4‐butanediol and trimethylolpropane were each used as chain extender agents. Results showed the PLA/PBA‐polyurethanes (PLA/PBA‐PUs) of the MDI series and the PLA/PBA‐PUs of the TDI series had improved thermal stability and enhanced mechanical properties. Degradation behavior showed the PLA‐based polyurethanes could be degraded in phosphate‐buffered saline solution and enzyme solution. © 2012 Society of Chemical Industry

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Section: Resultssupporting

confidence: 90%

Synthesis of poly(lactic acid)‐based polyurethanes

Chen

Tsao

Chou

et al. 2012

Polymer International

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“…It is probably due to rather small concentration of HAp, which may modify the local structure of POM in its neighborhood only. The peak corresponds to carbon atoms located within the chain of POM, for which the position at 88.4 ppm is reported in the literature …”

Section: Resultsmentioning

confidence: 72%

A study on the melting and crystallization of polyoxymethylene‐copolymer/hydroxyapatite nanocomposites

Pielichowska

Dryzek

Olejniczak

et al. 2012

Polymers for Advanced Techs

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In this work, isothermal crystallization kinetics of polyoxymethylene copolymer (POM) in POM/hydroxyapatite (HAp) nanocomposites has been investigated. Melting behavior and crystalline structure formation were studied using TOPEM DSC, positron lifetime spectroscopy (PALS), atomic force microscopy (AFM) and 13C and 31P solid‐state NMR. The highest degree of crystallinity was found for POM/0.5% HAp nanocomposite and the lowest for POM/2.5% HAp. Isothermal crystallization analysis showed that an introduction of HAp nanoparticles led to effective heterogeneous nucleation and formation of crystals with higher Avrami exponent. Besides, changes in overall crystallization rate were observed – the highest overall crystallization rate was found for POM/0.5% HAp sample, while the lowest for POM/2.5% HAp was observed. Generally, for POM in POM/HAp nanocomposites, a significant decrease in nucleation activation energy (Kg), and the fold surface free energy (σe) was found. For nanocomposite containing 2.5% HAp, heterogeneous nucleation takes place as well, but too high concentration of nanoparticles hinders POM crystallization and enhances formation of more defected crystals as confirmed by AFM data. The presence of HAp nanoparticles in the POM matrix was confirmed by 31P MAS‐NMR, but their influence on the crystallization process was not observed in the 13C CP‐MAS‐NMR spectra. Copyright © 2012 John Wiley & Sons, Ltd.

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“…As compared with neat PBT and PEGMA, some small chemical shifts in PBT/PEGMA appear between 70 and 78 ppm. Those signals should be the chemical shifts of “C*” as a result of the reaction between the PBT and PEGMA27 shown in Scheme .…”

Section: Resultsmentioning

confidence: 99%

Poly(butylene terephthalate)/clay nanocomposite compatibilized with poly(ethylene‐co‐glycidyl methacrylate). I. Isothermal crystallization

Huang

2008

J of Applied Polymer Sci

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Poly(butylene terephthalate) (PBT)/clay nanocomposite was prepared by blending PBT and commercial modified montmorillonite clays via a extruder by using poly(ethylene-co-glycidyl methacrylate) (PEGMA) as a compatibilizer (PBT/PEGMA/Clay). PEGMA and clay were also blended with PBT to prepare PBT/PEGMA and PBT/Clay, respectively. The morphology was investigated by wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The clays were aggregated together and phase separation was observed in PBT/Clay. The clays were exfoliated in PBT/PEGMA/Clay. The equilibrium melting temperature was estimated by linear and nonlinear Hoffman-Weeks relation. The influence of the PEGMA and clay on the PBT crystallizable ability was also investigated by Avrami model and undercooling (difference between crystallization and equilibrium melting temperature). Hoffman-Lauritzen relation was used to estimate chain fold surface free energy. The exfoliated silicates cause a large number nucleus center to enhance the crystallization in PBT/PEGMA/Clay. The presence of PEGMA can react with the PBT and an increase in viscosity would reduce molecular mobility and crystallization in PBT/ PEGMA. The aggregated clays have a confinement effect on the segmental motion of PBT and hinder the crystallization in PBT/Clay.

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A collection of solid-state13C CP/MAS NMR spectra of common polymers

Cited by 28 publications

References 13 publications

Synthesis of poly(lactic acid)‐based polyurethanes

Synthesis of poly(lactic acid)‐based polyurethanes

A study on the melting and crystallization of polyoxymethylene‐copolymer/hydroxyapatite nanocomposites

Poly(butylene terephthalate)/clay nanocomposite compatibilized with poly(ethylene‐co‐glycidyl methacrylate). I. Isothermal crystallization

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