Effect of bisphenol A on the miscibility, phase morphology, and specific interaction in immiscible biodegradable poly(ε‐caprolactone)/poly(L‐lactide) blends

Abstract

ABSTRACT:We have investigated the enhancement in miscibility, upon addition of bisphenol A (BPA) of immiscible binary biodegradable blends of poly(-caprolactone) (PCL) and poly(l-lactide) (PLLA). That BPA is miscible with both PCL and PLLA was proven by the single value of T g observed by differential scanning calorimetry (DSC) analyses over the entire range of compositions. At various compositions and temperatures, Fourier transform infrared spectroscopy confirmed that intermolecular hydrogen bonding existed between the hydroxyl group of BPA and the carbonyl groups of PCL and PLLA. The addition of BPA enhances the miscibility of the immiscible PCL/PLLA binary blend and transforms it into a miscible blend at room temperature when a sufficient quantity of the BPA is present. In addition, optical microscopy (OM) measurements of the phase morphologies of ternary BPA/PCL/ PLLA blends at different temperatures indicated an upper critical solution temperature (UCST) phase diagram, since the ⌬K effect became smaller at higher temperature (200°C) than at room temperature. An analysis of infrared spectra recorded at different temperatures correlated well with the OM analyses.

Mediated Competitive Hydrogen Bonding Form Mesoporous Phenolic Resins Templated by Poly(ethylene oxide-b-ε-caprolactone-b-l-lactide) Triblock Copolymers

“…We have reported that PVPh, phenolic, and bisphenol A (BPA) are totally miscible with PEO, PCL, and PLLA in the amorphous phase as a result of interassociation hydrogen bonding between the OH groups of the phenolic resins and either the CO groups of PCL and PLLA or the ether groups of PEO. ,, In general, DSC is a convenient method for determining the miscibility of polymer blends. The glass-transition temperatures ( T g ) of the pure polymers used in this studyphenolic, PEO, PCL, and PLLAare 66, −60, −60, and 57 °C, respectively. , Figure displays the conventional second-run DSC thermograms of various compositions of phenolic/ECL (here, ECL represents PEO- b -PCL- b -PLLA) blends (not cured with HMTA), recorded at a heating rate of 20 °C min –1 . The melting temperatures of the PEO, PCL, and PLLA blocks were all depressed, ultimately disappearing completely, upon increasing the content of phenolic resin in all four of our blend systems.…”

“…In this study, we investigated the behavior of PEO- b -PCL- b -PLLA triblock copolymers, comprising three immiscible crystallizable blocks, PEO, PCL, and PLLA, that are miscible with phenolic resin as a result of hydrogen bonding interactions. This system represents a new A- b -B- b -C/D blend type, where D is miscible with blocks A, B, and C. The strength of the hydrogen bonding interactions in this system follows the order phenolic/PEO > phenolic/PCL > phenolic/PLLA. ,, Several features have been observed in these blends: selective hydrogen bonding between the phenolic/PEO pair at relatively low phenolic contents; the coexistence of two competitive hydrogen bonding interactions (phenolic/PEO and phenolic/PCL pairs) at relatively high phenolic contents; and three competitive hydrogen bonding interactions (phenolic/PEO, phenolic/PCL, and phenolic/PLLA pairs) at the highest phenolic contents . These effects led to the formation of various composition-dependent nanostructures, including disordered-sphere, cylinder, and gyroid structures.…”

Preparation and Characterization of Poly(lactic acid)/Poly(butylene adipate-co-terepthalate) Blends and Their Composite

“…Blending PLA with other flexible and biodegradable polymers, such as poly(ethylene glycol) (PEG) [4] , poly(e-caprolactone) (PCL) [5][6][7][8][9] , poly(butylene adipate-co-terephthalate) (PBAT) [10,11] , poly(butylene succinate) (PBS) [12][13][14] , or an ethylene copolymer [15] is a practical method to improve toughness of PLA. Poly(butylene adipate-co-terepthalate)…”

Enhancement of bio‐compatibility via specific interactions in polyesters modified with a bio‐resourceful macromolecular ester containing polyphenol groups

“…Polymer blends based on PCL have been reviewed recently 29. In addition, the miscibility of PCL with low molecular weight phenols like 4,4′‐thiodiphenol (TDP)30, 31 and bisphenol‐A,32 have also been studied with expectation that these molecule could act as plasticizer to improve the processability and flexibility of PCL. In the blend systems of PCL and a hydroxyl containing polymers/small molecules, the driving force for the miscibility is the intermolecular H‐bonding interactions between proton‐donating polymers/small molecules and proton‐accepting PCL.…”