Acetoxypropyl cellulose

Fig. 7. Comparison of experimental phase boundary concentrations between the isotropic and biphasic regions for various liquid-crystalline polymer solutions with the scaled particle theory for wormlike hard spherocylinders. ( ) schizophyllan water [65] (A) poly y-benzyl L-glutamate) (PBLG)-dimethylformamide (DMF) [66-69] (A) PBLG-m-cresoI [70] ( ) PBLG-dioxane [71] (O) PBLG-methylene chloride [71] (o) po y(n-hexyl isocyanate) (PHICH°Iuene at 10,25,30,40 °C [64] (O) PHIC-dichloromethane (DCM) at 20 °C [64] (5) a po y(yne)-platinum polymer (PYPt)-tuchIoroethane (TCE) [33] ( ) (hydroxypropyl)-cellulose (HPC)-water [34] ( ) HPC-dimethylacetamide (DMAc) [34] (N) (acetoxypropyl) cellulose (APC)-dibutylphthalate (DBP) [35] ( ) cellulose triacetate (CTA)-trifluoroacetic acid [72]...

Cellulose based mesophases have displayed a somewhat steeper inverse dependence of pitch to concentration than that reported by Toriumi (29). A value of x = 3 has been reported for hydroxypropyl cellulose in water (31), for acetoxypropyl cellulose in acetone (32) and for hydroxypropyl cellulose in acetic acid and in methanol (28). Our data for cellulose in NH3/NH4SCN show a reasonably straight line when p l/3 was plotted vs. cellulose concentration (Figure 11), which is in accord with earlier reports (28,29,31,32). 

Gray et al. have reported that (acetoxypropyl)cellulose behaves as a thermotropic cholesteric liquid crystal below 164 °C. It has been also observed that some (hydroxy-propyljcellulose forms a thermotropic liquid crystalline phase at temperatures above 160 °C From these results together with our finding, we presume that rigid rod-like... 

Acetoxypropyl cellulose (APC) [74, 75] 2-Hydroxypropyl cellulose (HPC) [76] Trifluoroacetate ester of HPC [77] Propanoate ester of HPC [78] Benzoate ester of HPC [79] thin films... 

On the other hand, literature data show [16] that different cellulose derivatives which form liquid crystalline solutions in organic solvents may also form cholesteric thermotropic phases in the absence of a solvent—with spontaneous molecular orientation and cholesteric reflection, such as 2-acetoxypropyl cellulose, 2-hydroxypropyl cellulose, the trifluoroacetate ester of hydroxypropyl cellulose, the propanoate ester of hydroxypropyl cellulose, the benzoate ester of hydroxypropyl cellulose, 2-ethoxypropyl cellulose, acetoacetoxypropyl cellulose, trifluoroacetoxypropyl cellulose, the phenylac-etate and 3-phenylpropionate of hydroxypropyl cellulose, phenylacetoxy, 4-methoxy-phenylacetoxy, p-tolylacetoxy cellulose, trimethylsilyl cellulose, trialkyl cellulose, cellulose trialkanoate, the trialkyl ester of (tri-o-carboxymethyl) cellulose, 6-o-a-(l-methylnaphthalene)-2,3-o-pentyl cellulose, etc. Moreover, the suspensions of cellulose crystallites spontaneously form the chiral nematic phase. The formation of mesophase suspension of cellulose crystalHtes varies from one type of cellulose to another, being influenced, in the formation of the chiral nematic phase, by the mineral acid selected... 

In this context, literature [90] states that at room temperature, acetoxypropyl cellulose exhibits both chiral nematic phases—the lyotropic and the termotropic one. When subjected to specific conditions of shear flow, the cellulose derivative cholesteric liquid crystal suffers transformations, such as cholesteric helix and cholesteric-to-nematic transition. The films prepared from anisotropic solutions of termotropic acetoxypropyl cellulose in an isotropic solvent exhibit anisotropic mechanical properties, generated by the molecular orientation of the solution under shear stress. Thus, liquid crystalline solutions give rise to films with anisotropic mechanical properties the films are brittle when stretched parallel to the shear direction and ductile when stretched perpendicular to it. 

Second virial coefl cient of acetoxypropyl cellulose... 

Table 1. Second virial coefficient of acetoxypropyl cellulose.

Lagerwall JPF, Schiitz C, Salajkova M, Noh J, Hyun Park J, Scalia G, Bergstrom L (2014) Cellulose nanocrystal-based materials from liquid crystal self-assembly and glass formation to multifunctional thin films. NPG Asia Mater 6(l) e80 Laivins GV, Gray DG (1985a) Characterization and chain stiffness of (acetoxypropyl)cellulose. 

Maji S, Kundu S, Pinto LFV, Godinho MH, Khan AH, Acharya S (2013) Improved mechanical stability of acetoxypropyl cellulose upon blending with ultranarrow PbS nanowires in Langmuir monolayer matrix. Langmuir 29(49) 15231-15239 Mays JW (1988) Solution properties and chain stiffness of cyanoethyl hydroxypropyl cellulose. Macromolecules 21(11) 3179-3183... 

Acetoxypropyl cellulose Amylose hexanoate (2.9) 9004-39-1 257 315 Heating rate 5-10 K/min 1358 189... 

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