Thermal Properties and Degradation Behavior of Linear and Branched Poly(L‐lactide)s and Poly(L‐lactide‐co‐glycolide)s

Abstract

Poly(lactide)s and poly(lactide-co -glycolide)s with different number of arms are synthesized from L -lactide and glycolide monomers using stannous(II) 2-ethylhexanoate and alcohols containing 1, 2, 25, and 51 hydroxyl groups. 1-dodecanol is used to produce the 1-arm polymer, poly(ethylene glycol) for the 2-arm polymer, and polyglycidols of appropriate molecular weight are used to initiate the 25-and 51-arm branched polyesters. The polymers are characterized by 1 H NMR and GPC. The thermal properties of the polymers are studied using DSC. Their degradation behavior is indestigated using a combination of thermogravimetry, FTIR spectroscopy, and isoconversional kinetic analysis.

Thermal degradation kinetics and decomposition mechanism of PBSu nanocomposites with silica-nanotubes and strontium hydroxyapatite nanorods

“…Similar decomposition products, except succinic anhydride, were also View Article Online observed during decomposition of poly(butylene terephthalate) (PBT) and are due to the existence of 1,4-butylene glycol 37 while CO and CO 2 are due to the carboxyl end groups of polyesters. 38,39 At higher retention times allyl and diallyl compounds with characteristic vinyl groups and higher molecular weights were detected. Furthermore, it seems that the amount of decomposition products is directly dependent on the decomposition temperature.…”

Synthesis and characterization of polylactides with different branched architectures

“…One interesting aspect of the lactide ring‐opening reaction is the flexibility in designing different molecular architectures by employing multifunctional initiators. Different branched structures such as star‐shaped with arm numbers from 3 to 6, dendrimers, comb‐like, and barbell‐like molecules are synthesized by applying this strategy. An alternative procedure for the in situ synthesis of branched PLA is to use co‐monomers bearing initiation groups, such as 2,2‐ bis (hydroxymethyl) butyric acid in the presence of a tertiary amine, glycidol, and 5‐hydroxymethyl‐1,4‐dioxane‐2‐one .…”

Dynamic Mechanical Analysis and Hydrolytic Degradation Behavior of Linear and Branched Poly(L‐lactide)s and Poly(L‐lactide‐co‐glycolide)s

“…We previously reported26 the synthesis of PLLA and PLGA polymers with different number of arms via ring‐opening polymerization using stannous octoate with co‐initiators containing hydroxyl groups of 1, 2, 25, and 51. Linear (single arm) polymers PLLA35, PLGA12, and PLGA20 were initiated using 1‐dodecanol.…”

“…The polymers were previously designated using the following abbreviations: PLLA35, PLGA20, PLGA12, PEG‐PLLA7, PEG‐PLGA6, PG4‐PLLA2, and PG2‐PLGA2. Numbers following the abbreviation of the polyester represent the number average molecular weight of the polyester or polyester branch, while the numbers following the PG designation represent the peak molecular weight of the PG in kg mol −1 previously reported 26…”

“…The synthesis, thermal properties, and thermal degradation of PLA and PLGA polymers with different number of arms using co‐initiators containing hydroxyl groups of 1, 2, 25, and 51 was previously reported 26. 1‐Dodecanol was used to produce the 1‐arm linear polymers and copolymers.…”