02309nas a2200313 4500008004100000022001400041245009600055210006900151260000800220300001400228490000700242520130500249653001601554653001401570653001701584653001801601653002201619653001401641100003101655700002001686700002601706700001701732700002301749700001901772700002001791700002901811700003101840856012401871 2023 eng d a0032-388800aLuminescent 3D printed poly(lactic acid) nanocomposites with enhanced mechanical properties0 aLuminescent 3D printed polylactic acid nanocomposites with enhan cJUL a2059-20720 v633 a

The three-dimensional (3D) printing of functional composite materials has gained tremendous interest in recent years. Nevertheless, research on 3D printing of luminescent composite materials is very limited, and the mechanical properties of such 3D-printed composites are poor. Herein, we report the preparation and characterization of a poly(lactic acid) (PLA) composite that, when 3D printed, exhibits enhanced toughness and high solid-state fluorescence quantum yield. Incorporation of only 1 wt% pyrene butyric acid modified cellulose nanofibers (PBA-m-CNF) and l0 wt% thermoplastic polyurethane (TPU) into PLA led to 223% increase in toughness and 21% increase in tensile modulus of PLA. Scanning electron microscopy (SEM) and X-ray microcomputed tomography (mu-CT) analysis of the fractured cross-sections of 3D printed composites revealed a ductile failure mode. The PLA/PBA-m-CNF1/TPU10 3D printed composite also exhibited a high solid-state fluorescence quantum yield of 38.35%. To the best of our knowledge, this is the first report to show both enhanced mechanical properties and high solid-state fluorescence emission for 3D printable PLA. Such functional PLA composites could have potential applications in the fabrication of complex-shaped sensors, optical light pipes, etc.

10a3D printing10aComposite10afluorescence10aNanocellulose10apoly(lactic acid)10atoughness1 aKothavade, Premkumar, Anil1 aYadav, Prashant1 aNidhankar, Aakash, D.1 aTorris, Arun1 aPol, Harshawardhan1 aKafi, Abdullah1 aBateman, Stuart1 aSukumaran, Santosh, Babu1 aShanmuganathan, Kadhiravan uhttps://library.ncl.res.in/content/luminescent-3d-printed-polylactic-acid-nanocomposites-enhanced-mechanical-properties02487nas a2200277 4500008004100000022001400041245012500055210006900180260000900249300001400258490000600272520153800278653002001816653002001836653003501856653002101891653001401912100002501926700002001951700001901971700002301990700001902013700002002032700003102052856012602083 2024 eng d a2637-610500aEnhancing the crystallization kinetics and mechanical properties of poly(lactic acid) blends for 3D printing application0 aEnhancing the crystallization kinetics and mechanical properties cMAY  a5754-57620 v63 a

3D printing of poly(lactic acid) (PLA) blends has been attempted to resolve issues such as inherent brittleness and slow crystallization rate of PLA. However, a persistent challenge remains in the form of phase separation or gradual migration of the blended soft polymer or plasticizers. To simultaneously enhance the miscibility of the blends and toughness of 3D-printed parts, a triblock copolymer PLA-PEG-PLA was synthesized and blended with PLA in varying proportions (5, 10, 15, and 20 wt %). Blending only 10-20 wt % low molecular weight PLA-PEG-PLA into PLA yielded a miscible blend that showed a 45-fold increase in elongation at break and a 23-fold enhancement in toughness over neat PLA. Scanning electron microscopy (SEM) images of fractured cross sections revealed a brittle to ductile transition in 3D-printed PLA/PLA-PEG-PLA samples. Isothermal crystallization studies and data analysis using the Avrami equation showed an enhancement in the crystal growth rate and overall rate of crystallization. The blends achieved half of their crystallinity in approximately 3 min, a significant improvement over the 9 min required by PLA alone. This underscores the efficiency of our approach. This was also evident in the spherulite growth of 3D-printed PLA and mPLA blends when examined using polarized optical microscopy (POM). To the best of our knowledge, this is the first report exploring the use of blends that include PLA and low molecular weight PLA-PEG-PLA triblock copolymers for 3D printing applications.

10aCrystallization10aFFF 3D printing10aPLA-PEG-PLA triblock copolymer10apoly(lacticacid)10atoughness1 aKothavade, Premkumar1 aYadav, Prashant1 aGopal, Animesh1 aPol, Harshawardhan1 aKafi, Abdullah1 aBateman, Stuart1 aShanmuganathan, Kadhiravan uhttps://library.ncl.res.in/content/enhancing-crystallization-kinetics-and-mechanical-properties-polylactic-acid-blends-3d02707nas a2200241 4500008004100000022001400041245011300055210006900168260000900237300001400246490000600260520184600266653002002112653002002132653006402152653001402216653001202230100001902242700002002261700002302281700003102304856013002335 2025 eng d a2637-610500aUpcycling of postconsumer recyclate polypropylene into low warping and high toughness 3D printable filaments0 aUpcycling of postconsumer recyclate polypropylene into low warpi cJUN  a7373-73810 v73 a

Polypropylene (PP) is widely used in commodity applications owing to its chemical stability, mechanical properties and low cost. However, almost 50% of the produced PP ends up as postconsumer waste (PCW) within a short period of usage. Being a non-biodegradable polymer, recycling PCW PP is important to mitigate plastic waste in landfills. Nonetheless, recycling or upcycling postconsumer recyclate (PCR) PP into valuable resources without deterioration in physical and mechanical properties is a challenge. This report presents an approach to upcycle PCR polypropylene (rPP) into high quality 3D printing filament that not only prints with very low warpage but with significantly high elongation at break and toughness. Incorporation of poly(butylene adipate-co-terephthalate) (PBAT) along with maleic anhydride grafted polypropylene (MAPP) in specific proportions led to a significant enhancement in mechanical properties, miscibility, crystallization behavior, and 3D printability. rPP/PBAT blends with 20 wt % PBAT and 10 wt % MAPP exhibited a 62-fold enhancement in elongation at break over rPP (from 1.88 to 118.29%) and a 72-fold increase in toughness (from 2 to 143.60 kJ/m3) with almost similar tensile strength. The final printed components had better layer adhesion and structural stability with a dramatic decrease in warpage, from 25.82% for pristine rPP to only 7.86% for rPP/PBAT blend. Isothermal crystallization studies and data analysis using the Avrami equation showed that crystallization half-time (t 1/2), which measures the duration needed for half of the total crystallinity to form, increased from 12.6 s for rPP to 66 s for the rPP/PBAT blend. This report demonstrates an approach to upcycle PCR PP, a positive step toward realizing the goals of circular economy and sustainable additive manufacturing.

10aCrystallization10aFFF 3D printing10apolypropylene/poly(butylene adipate-co-terephthalate)blends10atoughness10awarpage1 aGopal, Animesh1 aPatil, Prashant1 aPol, Harshawardhan1 aShanmuganathan, Kadhiravan uhttps://library.ncl.res.in/content/upcycling-postconsumer-recyclate-polypropylene-low-warping-and-high-toughness-3d-printable