Temperature dependency of bound water of cellulose studied by a high‐resolution NMR spectrometer

Ogiwara, Yoshitaka; Kubota, Hitoshi; Hayashi, Shôichi; Mitomo, Noriko

doi:10.1002/app.1970.070140204

Cited by 45 publications

(16 citation statements)

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“…The latter finding is consistent with some literature data on water--cellulose interactions [7,8] and other theoretical approaches [9]. The latter finding is consistent with some literature data on water--cellulose interactions [7,8] and other theoretical approaches [9].…”

Section: Dn-a Dnsupporting

confidence: 92%

Interactions between paper and adsorbed molecules

Calvini¹,

Franceschi

Palazzi

et al. 1997

Journal of Thermal Analysis

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We have studied the geometry and energy involved in the interactions between adsorbed molecules and paper substrate, over a wide range of partial pressures. A two-dimensional virial equation of state was employed to evaluate the extent of interactions by the compressibility factor (Z). Data of H-bonded molecules (water and butan-l-ol) and of more weakly interacting ones (ndecane and dioxane) were selected from the literature. At low surface coverage, the compressibility factor Z exceeds 1, showing a deviation from ideality due to interactions, and reaches a maximum at a value close to the BET monolayer.As preliminary results we have measured by means of a differential microcalorimeter (Calvet) at 25~ the energy of interactions of water and n-heptane vapor on chromatographic grade Whatman paper.At very low coverage, the differential heats of adsorption of water on paper are higher than those of n-heptane adsorption on paper: 114 kJ mo1-1 > 77 kJ mo1-1. During the whole process of adsorption, in the first case, the specific interaction predominates, while in the second nonspecific interactions predominate i.e. the dispersion or Van der Waals forces.

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Section: Dn-a Dnsupporting

confidence: 92%

Interactions between paper and adsorbed molecules

Calvini¹,

Franceschi

Palazzi

et al. 1997

Journal of Thermal Analysis

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“…T g is one of the most important parameters in understanding mechanical properties of polymers, however, there has been limited research on the T g of cellulose and amorphous cellulose (Batzer and Kreibich 1981;Goring 1963;Kargin et al 1960;Ogiwara et al 1970;Salmen and Back 1977;Szczesniak et al 2008). Direct experimental measurements of the glass transition temperature of dry amorphous cellulose are not available in the literature, mainly because the temperature range for the main relaxation is close to the degradation temperature of cellulose (Mazeau and Heux 2003).…”

Section: Introductionmentioning

confidence: 99%

The glass transition and crystallization of ball milled cellulose

et al. 2010

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Samples of ball milled cellulose were prepared by ball milling pulps from eucalyptus and softwood (spruce/pine). Water sorption isotherms were obtained by both dynamic vapor sorption and equilibration over saturated salt solutions, in the water content range of 5-42% db (db = dry basis; water as a % age of total solids). Dynamic mechanical analysis using a pocket technique showed a water content dependent thermal transition occurring at the same temperature for the two pulp samples, which was interpreted as a glass transition. Fitting the data to a Couchman-Karasz relationship predicted a value for T g of the dry cellulose of approximately 478 K, which was similar to values previously reported for other dry polysaccharides. No clear glass transition could be observed calorimetrically, although an endotherm at approximately 333 K was measured, which in polymers is normally attributed to enthalpic relaxation, however the lack of dependence of this endotherm on water content suggests that the melting of some weak associations, such as residual hydrogen bonds, could be a more credible explanation. An exotherm was also observed on heating, which was dependent on water content and which was attributed to partial crystallization of the cellulose. This was confirmed by Wide angle X-ray diffraction and cross polarization magic angle spinning 13C NMR (CPMAS NMR). The recrystallisation was predominantly to form I of cellulose. This was thought to be caused by a small amount of residual form I (probably less than 5%) acting as a template for the crystallizing material. Differential scanning calorimetry reheat curves showed the appearance of freezable water for water contents higher than 20%, as a result of a transfer of water to the amorphous phase following crystallization. The increase in cellulose rigidity following crystallization was also confirmed by CPMAS NMR relaxation. Low resolution proton NMR T 2 relaxation suggested the presence of proton water/cellulose exchange, which was active at water contents of 20% and above

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“…The author noticed the thermal degradation of cellulose to occur at temperature exceeding 200°C. Ogiwara et al (1970) used high-resolution nuclear magnetic resonance (NMR) spectra of water bound in cellulose for the glass transition determination. The temperature dependence of the half-width of NMR spectra of cellulose with different water concentration was measured vs. temperature.…”

Section: Introductionmentioning

confidence: 99%

“…In the literature only a few experimental data are available on the influence of water content on the thermal behaviour and glass phase transition of cellulose (Goring 1963;Batzer and Kreibich 1981;Ogiwara et al 1970). This is due to difficulties in T g determining by DSC as pointed out by Vittadini et al (2001).…”

Section: Introductionmentioning

confidence: 99%

Glass transition temperature and thermal decomposition of cellulose powder

2007

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Cellulose powder and cellulose pellets obtained by pressing the microcrystalline powder were studied using differential scanning calorimetry (DSC), differential thermal analysis (DTA), and thermal gravimetry (TG). The TG method enabled the assessment of water content in the investigated samples. The glass phase transition in cellulose was studied using the DSC method, both in heating and cooling runs, in a wide temperature range from -100 to 180°C. It is shown that the DSC cooling runs are more suitable for the glass phase transition visualisation than the heating runs. The discrepancy between glass phase transition temperature T g found using DSC and predictions by Kaelbe's approach are observed for ''dry'' (7 and 5.3% water content) cellulose. This could be explained by strong interactions between cellulose chains appearing when the water concentration decreases. The T g measurements vs. moisture content may be used for cellulose crystallinity index determination.

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Temperature dependency of bound water of cellulose studied by a high‐resolution NMR spectrometer

Cited by 45 publications

References 5 publications

Interactions between paper and adsorbed molecules

Interactions between paper and adsorbed molecules

The glass transition and crystallization of ball milled cellulose

Glass transition temperature and thermal decomposition of cellulose powder

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