نوع مقاله : پژوهشی
نویسندگان
قم، دانشگاه صنعتی قم، دانشکده فنی و مهندسی، گروه مهندسی پلیمر، صندوق پستی 1519-37195
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Hypothesis: Poly(lactic acid) (PLA) is one of the most promising biodegradable polymers owing to its renewability, high mechanical strength, stiffness, and biocompatibility. However, its inherent brittleness considerably limits its engineering applications. Although blending PLA with poly(butylene adipate-coterephthalate) (PBAT) is an effective strategy for improving toughness, the poor interfacial compatibility between the two polymers results in an unfavorable phase morphology and restricts the simultaneous enhancement of strength and toughness. It was hypothesized that trifluoropropyl polyhedral oligomeric silsesquioxane (F-POSS) nanoparticles by improving the blend morphology and interfacial adhesion, could enhance mechanical properties of PLA/PBAT blends
Methods: PLA/PBAT blends with a weight ratio of 75/25 and nanocomposites containing 1, 3, and 5% (by wt) F-POSS nanoparticles were prepared by melt mixing. The phase morphology and nanoparticle localization were characterized by SEM and TEM, respectively. The rheological behavior was investigated by oscillatory rheometry, while crystallization behavior was studied using DSC. Tensile tests were performed to evaluate mechanical performance of the blends
Findings: TEM observations revealed that F-POSS nanoparticles were predominantly localized in the PLA matrix, while a portion of the nanoparticles was also distributed at the PLA/PBAT interface. The incorporation of F-POSS significantly refined the PBAT dispersed phase, narrowed the particle size distribution, enhanced interfacial adhesion, and reduced the matrix ligament thickness (τ), with the lowest τ being obtained for the blend containing 3% (by wt) F-POSS. Rheological analysis indicated a lubrication effect of F-POSS at low nanoparticle loading, whereas nanoparticle aggregation became dominant at higher concentrations. The DSC results showed that low F-POSS contents shifted the cold crystallization temperature of PLA to lower values without significantly affecting its crystallinity. The blend containing 3% (by wt) F-POSS exhibited the most pronounced improvement in ductility and tensile toughness. It was observed that extensive shear yielding of the PLA matrix was primarily responsible for the remarkable toughening of the blend.
کلیدواژهها [English]
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