Development of crosslinkable poly(lactic acid-co-glycidyl methacrylate) copolymers and their curing behaviors

Abstract

Crosslinkable poly(lactic acid-co-glycidyl methacrylate), P(LLA-co-GMA), copolymer was systematically synthesized by ringopening polymerization. Synthesis parameters, i.e., catalyst type, comonomer ratio and polymerization time and temperature were studied. The incorporated GMA content strongly affected the physical and thermal properties of the obtained copolymers, which varied from semi-crystalline to completely amorphous polymers. Melting and glass transition temperatures, and molecular weights of the copolymers decreased as the GMA content in the copolymer increased. Curing behavior of the copolymers was assessed by employing thermo-and photo-crosslinking processes, and the crosslink density was evaluated via their gel content and solvent swelling ratio. A photo-crosslinking process was proven as a practical method in the curing of the copolymers, as the reaction was almost complete within 2 min, as indicated by a gel content of 96%. In the thermo-crosslinking process, at least a 15-min curing time was required at 120 1C. The cured products of copolymers with 19.2 mol% GMA showed the highest compressive stress at 25.5 MPa.

Properties of poly(lactic acid)/hydroxyapatite composite through the use of epoxy functional compatibilizers for biomedical application

“…Characteristic bands at 1760 and 1720 cm À1 are due to the C ¼ O stretching modes of PLA and GMA, whereas bands at 1640 cm À1 were assigned to C ¼ C stretching modes of GMA. 37 A unique band at 815 cm À1 is due to the ¼CH 2 deformation mode of GMA. The band ratio of those two C ¼ O stretching mode can be employed to determine the GMA content in the composite.…”

Effect of poly (lactic acid)‐graft‐glycidyl methacrylate as a compatibilizer on properties of poly (lactic acid)/banana fiber biocomposites

“…. The characteristic peaks observed in 1 HNMR spectra of PLA and both GCs at δ = 1.57–1.58 ppm correspond to methine proton (―O―C H (CH 3 )―(CO)―), and δ = 5.1–5.2 ppm represents the methyl proton (―O―CH(C H 3 )―(CO)―) . However, additional peaks observed in the region between 1.09 and 4.3 ppm are associated to proton of ―CH, ―CH 2 and ―CH 3 groups in GMA.…”

“…The characteristic peaks observed in 1 HNMR spectra of PLA and both GCs at 1 δ = 1.57-1.58 ppm correspond to methine proton (-O-CH(CH 3 )-(C¼O)-), and 2 δ = 5.1-5.2 ppm represents the methyl proton (-O-CH(CH 3 )-(C¼O)-). [18,29,30] However, additional peaks observed in the region between 1.09 and 4.3 ppm are associated to proton of -CH, -CH 2 and -CH 3 groups in GMA. Moreover, the peaks at δ = 2.6, 2.8 and 3.2 ppm observed in GC are attributed to the proton of -OCH 2 and -CH groups belonging to epoxy functional group of GMA.…”

Crosslinking of Polylactide by High Energy Irradiation and Photo-Curing

“…All previous studies (above-mentioned works) were focused on crosslinking of PLA or PLA copolymers where curable groups were sited at the ends of polymer chains (end-functionalized polymers). In an alternative approach, poly(lactide-co-glycidyl methacrylate) (P(LA-co-GMA)) copolymer has been synthesized by ring-opening polymerization where curable C=C groups were placed in side-chains of the copolymer (pendant unsaturated groups) [ 76 ]. The copolymer was irradiated in the presence of an initiator and the influence of irradiation time, initiator concentration, as well as GMA content in polymer chain on crosslinking efficiency were followed by gel content measurement.…”