A Comparison of Three Different Biodegradable Aliphatic Oligoesters (PGA, PLLA, and PCL) with Similar Linear Alkyl End Groups by DSC and SAXS

The biodegradable aliphatic oligoesters polyglycolide (PGA), poly(L-lactide) (PLLA), and poly(E-caprolactone) (PCL) with similar number-average molecular weight M-n values but different linear alkyl end groups [CH3-[CH2-CH2](m)-CH2-] were compared in terms of their physical properties, parameters such as melting temperature (T-m), crystallinity (x(i)), long period (L), and lamella thickness (D). They were analyzed by DSC and SAXS. The effect of a longer and nonpolar alkyl end group such as docosyl [CH3-[CH2-CH2](10)-CH2-] on the long period (L) was more evident for PCL because it was the most nonpolar species in the family of oligoesters analyzed.