Transparent high-performance polymers are essential to avoid damage in automotive headlights when exposed to environmental conditions. An approach involving the synthesis of reinforced interpenetrating polymer networks (IPNs) based on poly(methyl methacrylate) (PMMA)/poly(urethane) (PU) with crystalline cellulose (C) is here proposed. The valorization of single-use cups used for cold beverage applications into reinforcement nanoparticle agents is studied through structural and morphological analysis, revealing intermediate crystallinity (52.51%) with a mixture of Iα (52.9%) and Iβ (46.3%) polymorphs in which the initial fiber had no chemical modification after the involved pretreatments. The effect of dispersing 0.1 wt% of C (d = 29 nm and L= 85–200 nm) into 50/50 and 80/20 PMMA/PU ratios is studied as a reinforcement agent under aging and environmental conditions (ASTM D1435-20) for 672 h. PMMA₈₀/PU₂₀ (σ =4 MPa, ε = 54%, E = 7 MPa) led to lower mechanical properties than PMMA₅₀/PU₅₀ (stress σ =14 MPa, strain ε = 94%, E = 83 MPa). PMMA₅₀/PU₅₀/C is reinforced in σ and ε with C addition (σ = 19 MPa, ε = 41%, E = 585 MPa) while PMMA₈₀/PU₂₀/C reduces both (σ = 3 MPa, ε = 51%, E = 5 MPa). This study indicates that aging increases stress while maintaining strain in the first but decreases in the second. The optical properties indicate no severe damage after aging.

Aim The purpose of this research was to analyze the antimicrobial activity ‐against food‐borne microorganisms‐ of modified chitosan‐starch films using formic and acetic acid as chitosan solvents and Melicoccus bijugatus leaves and fruit extracts. Methods and Results The effects of the modification process on the films’ antimicrobial activity against mesophilic aerobic bacteria, total coliform, and fungi (Sclerotinia sclerotiorum, Penicillium digitatum and Aspergillus Niger) were also analyzed. The previous contamination and antimicrobial tests were carried out in accordance with the Mexican Official Norms (NOM). The pH values of the films and extracts were measured, and the volatile compounds of the extracts, as well as those of QAfF10 and QAfH10 films were determined by Gas Chromatography–Mass Spectrometry (GC‐MS) considering the relationship among the type of compounds, the type and concentration of extracts, the pH of the films, and the antimicrobial activity against bacteria and fungi. The films that were prepared with formic acid as chitosan solvent, with a concentration of 5 and 10% (v/v) of leaves and fruit extracts, demonstrated the best antimicrobial activity in comparison with untreated chitosan–starch films. Conclusions The study showed that the extracts contain several compounds that improved the films' antimicrobial capacity and inhibited the growth of microorganisms with no previous sterilization required. The antimicrobial activity is correlated to the pH of the media, the combination of solvent/extract used and its concentration. Significance and impact of study This is one of the few researches were the antimicrobial activity of Melicoccus bijugatus extracts are studied. It was found that the presence of these extracts are capable of improve the antimicrobial activities of chitosan‐starch films. The performance of the modified films suggests their potential application as novel food packaging materials and encourages further research.

Interpenetrating polymer networks (IPNs) of poly(methyl methacrylate) (PMMA)/poly(urethane) PU exhibit good mechanical strength and weather resistance