Poly(lactic acid) properties as a consequence of poly(butylene adipate‐co‐terephthalate) blending and acetyl tributyl citrate plasticization

Abstract

This study was aimed at the modulation of poly(lactic acid) (PLA) properties by the addition of both a low-molecular-weight plasticizer, acetyl tributyl citrate (ATBC), and a biodegradable aliphatic-aromatic copolyester, poly(butylene adipate-co-terephthalate) (PBAT). PLA/PBAT, PLA/ATBC, and PLA/PBAT/ATBC mixtures with 10-35 wt % ATBC and/or PBAT were prepared in a discontinuous laboratory mixer, compression-molded, and characterized by thermal, morphological, and mechanical tests to evaluate the effect of the concentration of either the plasticizer or copolyester on the final material flexibility. Materials with modulable properties, Young's modulus in the range 100-3000 MPa and elongation at break in the range 10-300%, were obtained. Moreover, thermal analysis showed a preferential solubilization of ATBC in the PBAT phase. Gas permeability tests were also performed to assess possible use in food packaging applications. The results are discussed with particular emphasis toward the effects of plasticization on physical blending in the determination of the phase morphology and final properties.

Composition dependence of the synergistic effect of nucleating agent and plasticizer in poly(lactic acid): A Mixture Design study

“…I is achieved when the content of plasticizer is the highest. This effect is in contrast with the trend observed for the use of only a plasticizer in PLA, because usually the crystallinity developed during rapid cooling increases by increasing the plasticizer content [16,29,30]. In this case is the heterogeneity introduced by the plasticizer in nucleating crystals.…”

“…The addition of the plasticizer resulted in a decrease in glass transition temperature of PLA. However the addition of increasing amount of PBAT resulted in an increase in PLA glass transition temperature as a consequence of preferential migration of ATBC in the PBAT phase [16] and a general synergistic effect was evidenced on the overall crystallization rate of the PLA component when both PBAT and ATBC were added to PLA. In the industrial production usually PLA is melt processed and then rapidly cooled [2] below its glass transition temperature.…”

“…Plasticizers such as poly (ethylene glycol) [13], oligomeric lactic acid [14,15], citrate esters [16] are frequently used to tune PLA mechanical properties increasing its ductility. In terms of thermal properties the addition of a plasticizer usually results in a strong increase in spherulitic growth rate with respect to pure PLA.…”

Melt Rheology of Poly(Lactic Acid)/Low Density Polyethylene Polymer Blends

“…PLA have been blended with rubbers [3], thermoplastic starch (TPS) [4][5][6][7][8][9], poly(butylene succinate) (PBS) [10], poly(butylene succinate adipate) (PBSA) [11], poly(butylene adipateco-terephthalate) (PBAT) [12][13][14][15], acrilontryl-butadienestyrene (ABS) [16], polypropylene (PP) [17][18][19], and polystyrene (PS) [20,21], to obtain materials with lower cost and improved properties.…”

Isothermal Cold‐Crystallization of PLA/PBAT Blends With and Without the Addition of Acetyl Tributyl Citrate

“…Recent studies of Xiao et al [ 10 ] have shown that the addition of triphenyl phosphate as a plasticizer increases the spherulitic growth rate of PLA, as well as decreases the equilibrium melting temperature ( T m 0 ) as an effect of the plasticization of the chains. Previous work of Coltelli et al [ 1 ] showed the plasticizing effect of acetyl tributyl citrate (ATBC), which can induce a decrease in T g and an improvement in the mechanical properties of PLA/PBAT blends.…”