Toughening of Biodegradable Polylactide/Poly(butylene succinate-co-adipate) Blends via in Situ Reactive Compatibilization

Abstract

Polylactide and poly(butylene succinate-co-adipate) (PLA/PBSA) were melt-blended in the presence of triphenyl phosphite (TPP). An increase in the torque during melt mixing was used to monitor the changes in viscosity as compatibilization of the blends occurred. Scanning electron micrographs showed not only a reduction in the dispersed-phase size with increased TPP content but also fibrillated links between the PLA and PBSA phases, signifying compatibilization. Moreover, optimization of parameters such as the mixing sequence and time, TPP content, and PBSA concentration revealed that blends containing 30 and 10 wt % PBSA and 2 wt % TPP, which were processed for 30 min, were optimal in terms of thermomechanical properties. The impact strength increased from 6 kJ/m(2) for PLA to 11 and 16 kJ/m(2) for blends containing 30 and 10 wt % PBSA, respectively, whereas the elongation-at-break increased from 6% for PLA to 20 and 37% for blends containing 30 and 10 wt % PBSA, respectively. Upon compatibilization, the failure mode shifted from the brittle fracture of PLA to ductile deformation, effected by the debonding between the two phases. With improved phase adhesion, compatibilized blends not only were toughened but also did not significantly lose tensile strength and thermal stability.

The effect of MDI on the structure and mechanical properties of poly(lactic acid) and poly(butylene adipate-co-butylene terephthalate) blends

“…This had been widely investigated and believed to be attributed to the melting and recrystallization mechanism. 43,49,50 As the chain extension interfered in the crystallization process, many imperfect crystallites could be formed, and a large number of terminal groups and branched points generated imperfect crystallization. 51 In comparison with those of the neat PLA, the melting peak shape and amount of the blends exhibit almost no change.…”

Highly toughened polylactide with epoxidized polybutadiene by in-situ reactive compatibilization

“…Moreover, the price of a biodegradable polymer is very high due to its limited sources of raw materials. PLA/non-biodegradable polymer blends are also used in toughening PLA, like linear low-density polyethylene (LLDPE) [22], hydrogenated styrene-butadienestyrene block copolymer (SEBS) [23], acrylonitrile-butadienestyrene (ABS) [24], ethylene-n-butylacrylate-glycidyl methacrylate (EBA-GMA) [7,25], poly(butylenessuccinate-co-adipate) [26], poly(b-hydrox-ybutyrate-co-b-hydroxyvalerat) [27], expoxidized natural rubber (ENR) [12], glycidyl methacrylate grafted poly(-ethylene octane) [28]and polymerized soybean oil [29]. For both PLA/biodegradable and PLA/non-biodegradable blends, relatively high contents of flexible polymer is required to blend with PLA and the toughness is improved while the tensile strength and modulus are tremendous decrease [30].…”

Effects of magnesium silicate on the mechanical properties, biocompatibility, bioactivity, degradability, and osteogenesis of poly(butylene succinate)-based composite scaffolds for bone repair

“…8 Blending PBSu with poly(lactic acid) (PLA), poly(hydroxybutyrate) (PHB) or natural polymers, such as chitosan and silk fiber, has also been widely investigated. 9,10 Furthermore, the use of inorganic fillers is still the main approach for the modification of polymeric materials. In the previous investigation, mesoporous magnesium silicate (m-MS) has been revealed to possess rapid degradability, excellent in vitro bioactivity and cytocompatibility.…”