Ingeo biopolymer 3100hp

In order to find a correlation between the polymer’s structure and susceptibility to degradation, different grades of PLA were chosen as the objects of this investigation, namely: Ingeo^™ Biopolymer 2500HP, Ingeo^™ Biopolymer 3100HP, Ingeo^™ Biopolymer 3260HP, and Ingeo^™ Biopolymer 4032D, all of which were supplied by Nature Works (Minnetonka, MN, USA). The chosen properties of the resins are presented in Table 1.

The following chemicals were used as received: acetone (Sigma-Aldrich, ≥99.0%), chloroform (CHCl₃: VWR Chemicals, 99%), d-chloroform (CDCl₃: Apollo, >99%), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU: Sigma-Aldrich, 98%), diethyl ether (Et₂O: Sigma-Aldrich, ≥99.8%), N,N dimethylformamide (DMF: Fisher Scientific, LR grade), 2,6-di-tert-butyl-4-methylphenol (BHT: Alfa Aesar, 99%), ethyl acetate (EtOAc: Fisher Scientific, LR grade), hexane (Hex: VWR Chemicals, 99%), magnesium sulfate (MgSO₄: anhydrous, Fisher Scientific, LR grade), 3-mercapto-1-propanol (Tokyo Chemical Industry Ltd. UK, 96%), 1,3-propanediol (Sigma-Aldrich, 98%), propiolic acid (Acros Organics, 98%), silica gel (SiO₂: Apollo Scientific, 40-63 micron), sodium chloride (NaCl: Fisher Scientific, > 99%), sodium hydrogen carbonate (NaHCO₃: Fisher Scientific, >99%), sulfuric acid (Fisher Scientific, >95%), triethylamine (Et₃N: Fisher Scientific, LR grade). 1,6-hexanedithiol (Sigma-Aldrich, ≥97%) was vacuum distilled prior to use and stored in Young’s tapped ampuoles under N₂. Poly(l-lactic acid) (PLLA) (Ingeo™ Biopolymer 3100HP) was ordered from NatureWorks.