Preparation of poly(methyl methacrylate-co-maleic anhydride)/SiO2TiO2 hybrid materials and their thermo- and photodegradation behaviors

Morphological, Mechanical, and Antimicrobial Properties of PBAT/Poly(methyl methacrylate-co-maleic anhydride)-SiO2 Composite Films for Food Packaging Applications

A poly(methyl methacrylate-co-maleic anhydride) P(MMA-co-MA) copolymer was synthesized via radical polymerization. The synthesized P(MMA-co-MA) copolymer was identified by ¹H- and ¹³C-nuclear magnetic resonance spectroscopy (¹H-NMR), (¹³C-NMR), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The poly(butylene adipate-co-terephthalate) (PBAT)/P(MMA-co-MA)-SiO₂ composites were developed using a solution-casting method. The PBAT to P(MMA-co-MA) weight ratio was kept at 70:30, while the weight percentage of SiO₂ nanoparticles (NPs) was varied from 0.0 to 5.0 wt.%. SiO₂ was used for PBAT/P(MMA-co-MA) to solve the compatibility between PBAT and the P(MMA-co-MA) matrix. The PBAT/P(MMA-co-MA)-SiO₂ composites were characterized by studied FTIR spectroscopy, XRD, SEM, and TEM. A comparison of the composite film PBAT/P(MMA-co-MA)-SiO₂ (PBMS-3) with the virgin PBAT and P(MMA-co-MA) film revealed its good tensile strength (19.81 MPa). The WVTR and OTR for the PBAT/P(MMA-co-MA)-SiO₂ composites were much smaller than for PBAT/P(MMA-co-MA). The PBAT/P(MMA-co-MA)-SiO₂ WVTR and OTR values of the composites were 318.9 ± 2.0 (cc m^-2 per 24 h) and 26.3 ± 2.5 (g m^-2 per 24 h). The hydrophobicity of the PBAT/P(MMA-co-MA) blend and PBAT/P(MMA-co-MA)-SiO₂ composites was strengthened by the introduction of SiO₂, as measured by the water contact angle. The PBAT/P(MMA-co-MA)-SiO₂ composite films showed excellent antimicrobial activity against the food-pathogenic bacteria E. coli and S. aureus from the area of inhibition. Overall, the improved packaging characteristics, such as flexibility, tensile strength, low O₂ and H₂O transmission rate, and good antimicrobial activities, give the PBAT/P(MMA-co-MA)-SiO₂ composite film potential for use in food packaging applications.

Nonaqueous TiO2 nanoparticle synthesis: a versatile basis for the fabrication of self-supporting, transparent, and UV-absorbing composite films

A successful strategy to obtain self-supporting (100 microm), UV-absorbing, and, in the visible region, highly transparent TiO2-poly(methyl methacrylate) (PMMA) films was developed. The 15 nm large anatase TiO2 nanocrystals were prepared in a nonaqueous sol-gel approach involving the mixing of Ti(O(i)Pr)4 and benzyl alcohol. The surfaces of the resulting particles were modified with minute amounts of organic ligands in order to make the particles easily dispersible in nonpolar media like xylene and dichloromethane and compatible with PMMA, a polymer of high optical transparency and considerable technical importance. The empirical optimization process of composite fabrication was supplemented by fundamental studies of the crystallization and growth mechanism of anatase particles in a nonaqueous medium. After the preparation of corresponding nanocomposites, the materials were investigated with respect to their UV absorption capability, optical transparency in the visible-wavelength region, and photodegradation.