Novel PBAT‐Based Biocomposites Reinforced with Bioresorbable Phosphate Glass Microparticles

Biocomposites based on poly(butylene adipate terephthalate) (PBAT) and reinforced with micro-particles of inorganic biodegradable phosphate glass (PG) at 2, 10, and 40 wt% are prepared and characterized from a mechanical and morphological point of view. Scanning electron microscope (SEM) images show a good dispersion of the PG micro-grains, even at high concentrations, in the PBAT matrix, resulting in homogeneous composites. Tensile and dynamic-mechanical tests, respectively, indicate that Young’s and storage moduli increase with PG concentration. The reinforcement of PBAT aims at modifying and tailoring the mechanical and viscoelastic properties of the material to expand its application field especially in the food and agricultural packaging sector, thanks to the similarity of PBAT performance with polyethylene

Preparation and characterization of innovative poly(butylene adipate terephthalate)‐based biocomposites for agri‐food packaging application

The present work reports on the preparation and subsequent mechanical, morphological and thermal characterization of composites based on poly(butylene adipate terephthalate) (PBAT), reinforced with micro-particles of inorganic bioabsorbable calcium-phosphate glass (CPG) at different contents up to 40 wt%. The PBAT-CPG composites were prepared by solvent casting. The resulting composite pellets were used for the injection molding of model 1BA specimens, according to standard UNI EN ISO 527. PBAT-CPG composites displayed an effective increase of the Young's modulus (E) up to 82% compared to the pristine polymer, while showing a reduction of the yield stress (σy) up to 20%, of the stress at break (σB) up to 46%, of the strain at break (εB) up to 57% and of the toughness (T) up to 72%. The values of E, σy and σB were also compared and validated with theoretical values calculated using Kerner's and Pukanszky's models. Scanning electron microscopy (SEM) images display homogeneous dispersion and distribution of the filler particles in the polymer matrix with no aggregates or phase separation that would cause a deterioration of the material properties. Infrared (IR) spectroscopy did not show structural variations of the polymer matrix due to the CPG presence. The oxygen permeability in PBAT-based samples assumes significantly lower values when benchmarked with the permeability of low-density polyethylene (LDPE). Among the different composites, a decrease in oxygen permeability is observed as the CPG concentration increases. Regarding water vapor permeability, PBAT-based samples show a lower barrier effect than polyethylene (PE): in particular, permeability to water vapor assumes an increasing trend as the quantity of filler increases. The tuneable degradation of the final composite materials was defined by the disintegration degree (DD) determination under composting conditions in a laboratory-scale reactor. The developed materials prove to be valid biodegradable and eco-friendly alternatives to traditional thermoplastic polymers, such as LDPE, and can be applied in many fields, especially in package and mulch film applications

Design of Mechanical Properties of Poly(butylene-adipate-terephthalate) Reinforced with Zein-TiO2 Complex

Mechanical properties of polymer biocomposites are influenced by the interaction between thematrix and the filler surface. In this work, composites based on poly(butylene-adipate-terephthalate) (PBAT) filled with micrometric particles of zein-TiO2 complex (ZTC) were realized via solvent casting technique at different concentrations, equal to 0, 5, 10, and 20 wt%. After pelletization, the resulting materials were injection molded into standard specimens, employed for the uniaxial tensile test (UTT) characterization. From the stress-strain curves, Young’s modulus (E), yield stress (σy), stress at break (σB), elongation at break (εB), and toughness (T) were collected. The addition of the ZTC proved to show a reinforcing effect on the polymeric matrix, with an increase in both E and σy. Modelling of the mechanical properties was performed by applying Kerner’s and Pukánszky’s equations. Kerner’s model, applied on experimental E values, returned a very good correspondence between collected and theoretical values. From the application of Pukánszky’s model to σy, the obtained B value showed a good interfacial interaction between the matrix and the filler. Due to the enhanced stiffness of the composites, a reduction in the true stress at break (σT,B) was observed. The modified Pukánszky’s model gave a B value lower than the one obtained for the yield, but still in the range of acceptable values for microcomposites

Preparation and characterization of innovative poly(butylene adipate terephthalate)-based biocomposites for agri-food packaging application

The present work reports on the preparation and subsequent mechanical, morphological and thermal characterization of composites based on poly(butylene adipate terephthalate) (PBAT), reinforced with micro-particles of inorganic bioabsorbable calcium-phosphate glass (CPG) at different contents up to 40 wt%. The PBAT-CPG composites were prepared by solvent casting. The resulting composite pellets were used for the injection molding of model 1BA specimens, according to standard UNI EN ISO 527. PBAT-CPG composites displayed an effective increase of the Young's modulus (E) up to 82% with respect to the pristine polymer, while showing a reduction of the yield stress (σy) up to 20%, of the stress at break (σB) up to 46%, of the strain at break (εB) up to 57% and of the toughness (T) up to 72%. The values of E, σy and σB were also compared and validated with theoretical values calculated using Kerner’s and Pukanszky’s models. Scanning electron microscopy (SEM) images display homogeneous dispersion and distribution of the filler particles in the polymer matrix with no aggregates or phase separation that would cause a deterioration of the material properties. Infrared (IR) spectroscopy did not show structural variations of the polymer matrix due to the CPG presence. The oxygen permeability in PBAT-based samples assumes significantly lower values when benchmarked with the permeability of low-density polyethylene (LDPE). Among the different composites, a decrease in oxygen permeability is observed as the CPG concentration increases. Regarding water vapor permeability, PBAT-based samples show a lower barrier effect than PE: in particular, permeability to water vapor assumes an increasing trend as the quantity of filler increases. The tuneable degradability of the final composite materials was defined by the disintegration degree (DD) determination under composting conditions in a laboratory-scale reactor. The developed materials prove to be valid biodegradable and eco-friendly alternatives to traditional thermoplastic polymers, such as LDPE, and can be applied in many fields, especially in package and mulch film applications

Preparation and Characterisation of PBAT-Based Biocomposite Materials Reinforced by Protein Complex Microparticles

In this work, new biodegradable composite materials based on poly (butylene adipate terephthalate) (PBAT) reinforced with zein–TiO2 complex microparticles were prepared and characterised by electron microscopy and tensile and dynamic-mechanical tests. The composite pellets were prepared by solvent casting with different filler contents, namely 0, 5.3, 11.1 and 25 part per hundred resin (phr), to modify and modulate the properties of the final materials. Scanning electron microscopy (SEM) images showed homogeneous dispersion of the filler, without microparticles aggregation or phase separation between filler and matrix, suggesting a good interphase adhesion. According to tensile tests, Young’s modulus showed an improvement in the rigidity and the yield stress presented an increasing trend, with opposite behaviour compared to other composites. Dynamic-mechanical analysis (DMA) results exhibited increasing storage modulus values, confirming a greater rigidity with a higher filler percentage. The glass transition temperature showed a slightly increasing trend, meaning the presence of an interaction between the two phases of the composite materials. Overall, the produced PBAT composites showed similar properties to low-density polyethylene (LDPE), proving to be promising and more sustainable alternatives to traditional polymers commonly adopted in agri-food fields

PREPARATION AND CHARACTERIZATION OF POLYMER-BASED BIOCOMPOSITES FOR AGRI-FOOD PACKAGING APPLICATIONS

The present work aims at the preparation and subsequent mechanical, morphological and thermal characterization of composites based on poly(butylene adipate terephthalate) (PBAT), loaded with micro-particles of inorganic biodegradable phosphate glass (PG)i at 2, 4, 10, 20 and 40 wt%. The reinforcement of PBAT has the purpose of modifying and modulating the mechanical and thermo-mechanical properties of the material to expand its application field especially in the food and agricultural packaging sectorii, thanks to the similarity of PBAT performance with polyethylene (PE)iii. The PBAT-PG specimens were subjected to uniaxial tensile stress and the collected data were analysed to obtain characteristic parameters such as Young's modulus (E), yield stress (σy), stress at break (σB), elongation at break (εB) and toughness (T) (Fig. 1). Scanning electron microscopy (SEM) images display homogeneous dispersion and distribution of the filler particles in the polymer matrix with no aggregates or phase separation (Fig. 2). PBAT is considered as one of the most promising biodegradable polyesters and this work demonstrates the successful realization of a PBAT-based composite material, as valid biodegradable and eco-friendly alternative to traditional thermoplastic polymers, such as PE

Flexible PBAT-Based Composite Filaments for Tunable FDM 3D Printing

Biobased composites with peculiar properties offer an attractive route for producing environmentally friendly materials. The reinforcement for poly(butylene adipate-co-terephthalate) (PBAT), based on zein-titanium dioxide (TiO2) complex (ZTC) microparticles, is presented and used to produce composite filaments, successfully 3-dimensionally (3D) printed by fused deposition modeling (FDM). The outcome of ZTC addition, ranging from 5 to 40 wt %, on the thermo-mechanical properties of composite materials was analyzed. Results reveal that storage modulus increased with increasing the ZTC content, leading to a slight increase in the glass transition temperature. The creep compliance varies with the ZTC concentration, denoting a better resistance to deformation under constant stress conditions for composites with higher complex content. Scanning electron microscopy was used to assess the quality of interphase adhesion between PBAT and ZTC, showing good dispersion and distribution of complex microparticles in the polymer matrix. Infrared spectroscopy confirmed the formation of a valid interface due to the formation of hydrogen bonds between filler and polymer matrix. Preliminary tests on the biocompatibility of these materials were also performed, showing no cytotoxic effects on cell viability. Finally, the 3D printability of biobased composites was demonstrated by realizing complex structures with a commercial FDM printer

Tunable FDM 3D printing of flexible poly(butylene adipate terephthalate)-based biocomposite filaments

Poly(butylene adipate-co-terephthalate), PBAT, is a synthetic and 100% biodegradable polymer based on fossil resources, with high elongation at break and high flexibility. These properties are comparable to lowdensity polyethylene, making PBAT a very promising biodegradable material that could replace it in some industrial applications. However, its lower mechanical properties have limited its application range. The reinforcement of PBAT with rigid filler, such as zein-TiO2 (ZTC) complex microparticles, has the purpose to expand its application fields, from the food and agricultural packaging to healthcare sector. The 3D printability of bio-based composites was demonstrated by realizing complex structures with a commercial FDM printer

Novel PBAT-based biocomposites reinforced with bio-absorbable phosphate glass microparticles

Biocomposites, based on poly(butylene adipate terephthalate) (PBAT) and loaded with micro-particles of inorganic biodegradable phosphate glass (PG) at 2, 10 and 40 wt%, are prepared and characterized from a mechanical and morphological point of view. Scanning electron microscope images show PG micro-grains are well dispersed, even at high concentrations, in the PBAT matrix resulting in homogeneous composites. Tensile and dynamic-mechanical tests indicate Young and storage moduli respectively increase with PG concentration. The reinforcement of PBAT has the purpose of modifying and modulating the mechanical and thermo-mechanical properties of the material to expand its application field especially in the food and agricultural packaging sector , thanks to the similarity of PBAT performance with polyethylene