Reactive compatibilization of PLA/PBS bio‐blends via a new generation of hybrid nanoparticles

Abstract

Poly(butylene succinate) (PBS) is a worthy biodegradable thermoplastic polyester for blending along with other biopolymers, especially with poly (lactic acid) (PLA), to overcome its inadequacies in mechanical and thermal characteristics. Since binary blends of PLA and PBS showed that they are incompatible, compatibilization is required. In this work, multi‐epoxide polyhedral oligomeric silsesquioxane (Glycidyl POSS) was added to PLA and PBS using the melt blending method to make them compatible. The blends were prepared at different weight ratios having different amounts of compatibilizer. SEM analysis showed that the Glycidyl POSS impacted the interfacial adhesion and other properties of PLA and PBS blends. Noticeable improvements in mechanical properties were revealed by tensile and impact test results. Tensile strength and Young's modulus were improved when epoxy‐POSS was added up to 1 and 3 wt% into ternary blends, but further increasing POSS concentrations resulted in lower values. FTIR analysis showed a strong interaction between the epoxide group of POSS and the end groups of PBS or PLA. The thermal properties of samples were analyzed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The shifts in glass transition temperatures of the PLA phase towards lower values appeared in DSC, confirming the enhanced compatibility of PLA and PBS. Also, the reinforcing ability of the POSS inorganic core structure impacted the thermal stability of the blends.

Miscibility and phase behavior of reactively compatibilized poly(lactic acid)/poly(butylene succinate) bio‐blends using various rheological analyses

“…As shown in Figure 7, epoxide groups of POSS types can react with COOH and/or OH functional end groups of PLA and/or PBS. Moreover, we have proved these interactions in our previous work 15 using FTIR analysis and rheological investigations in the molten state of PLA/PBS blends compatibilized with MuEpPOSS. Complex viscosity values in the presence of MuEpPOSS were greater than in the presence of MoEpPOSS, attributing to the presence of multiple numbers of epoxide groups at the cage structure of MuEpPOSS leading toward stronger interactions between POSS and polymers.…”

“…With the increase in the amount of PBS in the PLA/PBS blend, the complex viscosity value decreased due to the low viscosity of the PBS and the weak interaction between PLA‐PBS. In our previous article, 15 this phenomenon of phase separation upon adding higher PBS contents into PLA/PBS blends was explained in detail. We investigated the morphology of PLA/PBS binary blends using SEM analysis.…”

“…[11][12][13] According to prior studies related to the PLA-based biodegradable polymer blends, both polymers were incompatible in PLA/PBS blends at more than 20 wt% of PBS, which caused a reduction in mechanical strength and the transformation of rheological properties like complex viscosity, storage modulus, and loss modulus. [13][14][15] The addition of functional nanoparticles is one probable method for making immiscible polymers compatible. An ideal additive for PLA/PBS matrix should be compatible and dispersible at the microscale level.…”

The role of additives in rheology and processing

“…Kodal et al employ reactive compatibilization using a glycidyl polyhedral oligomeric silsesquioxane (POSS) additive, which is an Si-O cage-like nanoparticle with added epoxide functionality. [12] Osswald et al formulated vitrimers, a class of cross-linked polymers that can be re-melt processed like thermoplastics. [13] The authors describe the use of polyethylene with various ratios of glycidyl methacrylate (GMA) and 3,3 0 -dithiodipropionic acid (DTDPA) cross-linkers.…”

Fluorinated‐polyhedral oligomeric silsesquioxane (F‐POSS) functionalized halloysite nanotubes (HNTs) as an antifouling additive for epoxy resin

“…[31][32][33] Hybridization of mineral nanoscale fillers has also been recognized as a useful method to gain high-performance epoxy nanocomposite coatings. [34][35][36] However, a few is known about antifouling epoxy/POSS nanocomposites through surface hydrophobicity manipulation. Application of organosilanes-based coatings was also practiced, because of being promising it terms of simple formulation and large window of properties for advanced application.…”