Poly(L-lactide) macrodiols (HOPLLAOH): Influence of linear alkyl diols as initiators: Synthesis and characterization

ABSTRACT

A series of α,ω-hydroxy telechelic poly(L-lactide)s (HOPLLAOHs) were synthesized by ring-opening polymerization (ROP) of L-lactide (L-LA) using tin octoate [Sn(Oct)₂] as catalyst and a family of linear alkyl diols as initiators [HO–[CH₂]_m–OH, where m = 2, 4, 6, 8, 10, and 12]. A systematic analysis of these HOPLLAOHs species in terms of their thermal properties was realized by DSC. In this sense, the linear alkyl group had an important influence on the glass transition temperature (T_g); a relatively high content of alkyl group on the HOPLLAOH increased the flexibility of the polyester, evidenced by a value of T_g inversely proportional to the weight percent of the alkyl group. Besides, the alkyl groups had an effect on the crystallization temperature (T_c), melting temperature (T_m), and crystallinity (x_i). Additionally, HOPLLAOHs were characterized by ¹H and ¹³C NMR, FT-IR, MALDI-TOF, and GPC.

KEYWORDS:

• Alkyl group
• DSC
• glass transition temperature
• macrodiol
• poly(L-lactide)

Acknowledgments

J.E.B. thanks Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico) and the University of Guanajuato (UG) for the recent opportunity to work as Assistant Professor. Marvin was used for drawing, displaying, and characterizing chemical structures, substructures, and reactions (Marvin Sketch 6.1.3, 2013, ChemAxon; http://www.chemaxon.com); a free software program with an academic license was provided by ChemAxon.