Table 2.

Physical properties of the lactides.

Physical Properties	L-Lactide	D-Lactide	Meso-Lactide	Rac-Lactide
Molecular weight (g/mol)	144.12	144.12	144.12
Optical rotation in degrees	−260	+260
Specific rotation (polarimetry toluene, 25 °C)	(−287)–(−300)°	(+287)–(+300)		(−1)–(+1)°
Appearance (visual test)	White crystals
Melting point (°C)	95–100	95–100	53–54	122–128
Boiling point (°C)	255			142
Heat of fusion (J/g)	146		118; 128	120–170 (DSC 10 °C/min)
Heat of vaporization (kJ/mol)	63
Solid density (g/mL)	1.32–1.38		1.32–1.38
Liquid viscosity (mPas) (110 °C)	2.71
Liquid viscosity (mPas) (120 °C)	2.23
Liquid viscosity (mPas) (130 °C)	1.88