Lactide miscibility

Blend films of poly(L-lactide) (PLLA) and poly(vinyl alcohol) (PVA) were synthesized. The component interaction, crystallization behavior, and miscibility of these blends were studied by solid-state NMR. ... 

It is miscible with water and alcohol, and is slightly soluble in ether. It decomposes when heated, but when distilled under a pressure of 1 mm. it is obtained as a liquid, which solidifies in a freezing mixture to crystals which melt at 18°. At 150° lactic acid loses water and lactide (m.p. 124°, b.p. 255°) is formed —... 

Kikkawa, Y Suzuki, T Kanesato, M. Doi, Y and Abe, H. Effect of phase structure on enzymatic degradation in poly(L-lactide)/atactic poly(3-hydroxybutyrate) blends with different miscibility. Biomacromole. 2009,10(4), 1013-1018. 

Liu, T.Y., Lin, W.C., Yang, M.C., Chen, S.Y. Miscibility, thermal characterization and crystallization of poly(l-lactide) and poly(tetramethylene adipate-co-terephthalate) blend membranes. Polymer 46(26), 12586-12594 (2005)... 

Shuai, X., He, Y, Asakawa, N., and Inoue, Y. 2001. Miscibility and phase structure of binary blends of poly(L-lactide) and poly(vinyl alcohol). Journal of Applied Polymer Science 81 762-772. 

Edlund, U. and Albertsson, A.-C. (2000) Microspheres from poly(D,L-lactide)/poly(l,5-dioxepan-2-one) miscible blends for controlled drug delivery. Journal of Bioactive and Compatible Polymers, 15,... 

PHA blends with poly(vinyl alcohol) (PVA) are interesting materials whose miscibility depends on the composition and the PVA tacticity [178]. PHB is claimed to be miscible with polyethylene glycol [179] and with poly D-lactide [180] its miscibility with polyethylene oxide depends on the blend composition [181]. Immiscible, but well-compatible blends of PHB, were prepared with poly(butylene succinate-co-butylene adipate) and poly(butylene succinate-co-caprolactone) [182]. 

Sakai, E, Nishikawa, K., Inoue, Y., and Yazawa, K. (2009) Nucleation enhancement effect in poly(L-lactide) (PLLA)/poly(8-caprolactone) (PCL) blend induced by locally activated chain mobility resulting om limited miscibility. Macromolecules, 42, 8335-8342. 

In a separate study, PCL (molecular weight 15,000) was blended with poly(L-lactide) (molecular weight 10,000) by casting from solutions in chloroform and drying under vacuum at 60 °C for 24 h. DSC scans of samples heated to 200 °C and quenched showed that the Tg of poly(L-lactide) overlapped with the Tj of PCL, which rendered detailed analysis of the thermograms and assessment of polymer-polymer miscibility difficult. However, the cold-crystallisation exotherm of pure poly(L-lactide), at 131 °C, was shifted in the blends containing more than 50 wt % poly(L-lactide) to about 95 "C this shift was independent of the poly(L-lactide) content. In addition, the crystallisation rate for PCL was... 

The synthesis of lactide was first described by Pelouze in 1845 [71]. He investigated the self-esterification of lactic acid by heating and driving off water and obtained a prepolymer that was no longer fully miscible with water. Upon continued heating of the prepolymer, he noticed that in a certain distillate fraction nice crystals were formed. He was able to deduce the chemical formula and gave the name lactid to the substance. An improved procedure was... 

CHEMISTRY AND THERMODYNAMIC PROPERTIES OF LACTIC ACID AND LACTIDE AND SOLVENT MISCIBILITY... 

The miscibility of lactic acid and lactide with supercritical CO2 was studied by Gregorowicz [24]. The solubility of the monomer in a supercritical solvent depends on temperature, pressure, and overall composition of the reacting mixture equilibrium between different phases. It is possible that the concentration of the monomer in the supercritical fluid phase may vary over a wide range. In general, the solute solubility in compressed carbon dioxide increases as pressure increases from 50 to 200 bar (Figure 2.1). At pressures below 130 bar, the solubility decreases as temperature increases. Thus, it is... 

Lactide is miscible with benzene, toluene, xylene, methylene chloride, chloroform, tetrahydrofuran, ethyl acetate, methanol, isopropanol, acetone, and butanone. The solubility increases with increasing temperature [25]. Lactide will hydrolyze to lactic acid in water at room temperature, and the rate of hydrolysis of we50-lactide is much higher than that of D,L-lactide [26]. 

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