The solution and transport of water vapor in poly(acrylonitrile): a re-examination

Mauze, G.R.; Stern, S. A.

doi:10.1016/0376-7388(82)80003-3

Cited by 61 publications

(21 citation statements)

References 13 publications

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“…The equilibrium is consistent with a type II isotherm in the Brunauer-Deming-Deming-Teller (BDDT) [6] classification scheme. Type II isotherms have been observed for water in a range of polymers [7] including polyphenylene oxide [8], polyimide films [9], poly(ammonium sulfopropylbetaines) [10], PVA [11], PNIB [12], Nafion [13], polyacrylonitrile [14], and in Kevlar [15]. Other studies have made water sorption measurements in a PDMS elastomer prepared from crosslinking vinyl terminated polydimethylsiloxane chains with 2,4-dichlorobenzoylperoxide [16] and tetrahydrosiloxane [17].…”

Section: Water Sorption In Unfilled Silicone Foammentioning

confidence: 99%

Water sorption in silicone foam containing diatomaceous earth

Rutherford

Coons

2007

Journal of Colloid and Interface Science

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Section: Water Sorption In Unfilled Silicone Foammentioning

confidence: 99%

Water sorption in silicone foam containing diatomaceous earth

Rutherford

Coons

2007

Journal of Colloid and Interface Science

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“…Some instances of an increase in b with temperature have been reported. 39 In order to test the predictive capability of the dual mode theory for different temperatures, sorption experiments were carried out at 45.0"C for the system XD7342jTMAB cured at 195°C for 24 h. The values of the dual mode parameters for 45.0"C can be predicted from eq. (3) Table VI.…”

Section: Equilibrium Sorptionmentioning

confidence: 99%

Effect of time‐temperature path of cure on the water absorption of high T_g epoxy resins

Aronhime

Peng

Gillham

et al. 1986

J of Applied Polymer Sci

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synopsisThe effect of different time-temperature paths of cure on the water absorption of high Tg epoxy resins has been investigated. The resins were cured isothermally for different times, with the following results:. as extent of cure increased, the glass transition temperature (T,) increased, the room temperature (RT) modulus decreased, the RT density decreased, the RT diffusion coefficient appeared to decrease, and the RT water absorption increased. The decrease in RT density is related to an increase in free volume, which controls the amount of water absorbed. A qualitative model accounts for the increase in RT free volume with increasing cure. The model is based on a restricted decrease of free volume on cure due to the rigid molecular segments in the cured resin systems. The sorption isotherms can be characterized by the dual mode theory at low activities but at high activities the sorption is complicated by penetrant clustering. A thermodynamic approach, independent of the absorption model, can correlate sorption data at different temperatures. The diglycidyl resin was also cured for extended times at three temperatures, in a n effort to achieve full cure at each temperature.For these, the higher the cure temperature, the lower the RT density, which could result from the lower initial density of materials cured at higher temperatures. The equilibrium water absorption increased with increasing cure temperature, consistent with the decrease in RT density. The systems studied were a diglycidyl ether of bisphenol A cured with a n aromatic tetrafunctional diamine, trimethylene glycol di-p-aminobenzoate (Tgm = 156"C), and a triglycidyl ether of tris(hydroxypheny1)methane cured with the same amine (TSm = 268°C).

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“…On one hand, it was proposed that specific siteinteraction water was located on the glassy amorphous region 4 of polymer sorbents and could not be frozen. 5 This was referred to directly and tightly bound water that present in interpolymer molecular space. Water molecules acted as a plasticizer causing a lowering of the glass transition temperature of polymer sorbents.…”

Section: Introductionmentioning

confidence: 99%

Thermal porosity analysis of croscarmellose sodium and sodium starch glycolate by differential scanning calorimetry

Faroongsarng

Peck

2003

AAPS PharmSciTech

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KEYWORDS: thermoporometry, differential scanning calorimetry (DSC), croscarmellose sodium (CCS), sodium starch glycolate (SSG) The aim of the study was to demonstrate the applicability of differential scanning calorimetry (DSC) on porosity analysis for cellulose and starch. Croscarmellose sodium (CCS) and sodium starch glycolate (SSG) were allowed to sorb moisture in 85%, 90%, 95%, and 100% relative humidity (RH) at 40°C for 24 hours. The pretreated samples were then subjected to DSC running temperature ranging from 25°C to -50°C at a cooling rate of 10°C/min. The cooling traces of water crystallization, if present, were transformed to porosity distribution via capillary condensation using Kelvin's equation. The porosity analysis of CCS and SSG was also done using nitrogen adsorption as a reference method. It was found that sorbed water could not be frozen (in cases of 85% and 90% RH) until the moisture content exceeded a cutoff value (in cases of 95% and 100% RH). The nonfreezable moisture content was referred to tightly bound, plasticizing water, whereas the frozen one may be attributed to loosely bound water condensation in pore structure of CCS and SSG surfaces. Not only capillary condensation but also the tightly bound, nonfreezable monolayer water lying along the inner pores of the surface contributed to porosity determination. Good agreement with less than 5% deviation of mean pore size was observed when the results were compared with nitrogen adsorption. The narrower pore size distributions, however, were obtained because of the limitations of the technique. It was concluded that pore analysis by DSC could be successful. Further research needs to be done to account for limitations and to extend the applicability of the technique.

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The solution and transport of water vapor in poly(acrylonitrile): a re-examination

Cited by 61 publications

References 13 publications

Water sorption in silicone foam containing diatomaceous earth

Water sorption in silicone foam containing diatomaceous earth

Effect of time‐temperature path of cure on the water absorption of high T_g epoxy resins

Thermal porosity analysis of croscarmellose sodium and sodium starch glycolate by differential scanning calorimetry

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The solution and transport of water vapor in poly(acrylonitrile): a re-examination

Cited by 61 publications

References 13 publications

Water sorption in silicone foam containing diatomaceous earth

Water sorption in silicone foam containing diatomaceous earth

Effect of time‐temperature path of cure on the water absorption of high Tg epoxy resins

Thermal porosity analysis of croscarmellose sodium and sodium starch glycolate by differential scanning calorimetry

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Product

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Effect of time‐temperature path of cure on the water absorption of high T_g epoxy resins