02707nas 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<p>
	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.</p>
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-printable02302nas a2200241   4500008004100000022001400041245011300055210006900168260000800237300001400245490000700259520147700266653002001743653002001763653003701783653001401820653001401834653001201848100001901860700001801879700003101897856013201928       2026                        eng d  a0032-388800aLow warping and high toughness recycled high density polyethylene for fused filament fabrication 3D printing0 aLow warping and high toughness recycled high density polyethylen  cJUN  a4390-44020 v663 a<p>
	The incorporation of recycled polymers in additive manufacturing offers a sustainable pathway to reduce plastic waste while enabling cost-effective production of functional components. High-density polyethylene (HDPE) is an attractive material for 3D printing owing to its low density, chemical resistance, and recyclability. However, its high crystallinity and tendency to shrink often lead to warpage and poor interlayer adhesion. This study proposes a blend-based strategy to overcome these limitations by incorporating tough linear low-density polyethylene (LLDPE) into recycled HDPE (rHDPE). The blends were prepared through melt extrusion, and their mechanical, rheological, morphological, and thermal properties, and 3D printability were comprehensively evaluated. rHDPE/LLDPE blends showed a remarkable improvement in elongation at break (from 3.2% to 84.7%) and toughness without compromising tensile strength. Addition of LLDPE led to a moderate reduction in the crystallinity of rHDPE/LLDPE blends (from 69% to 52.5%) but a significant reduction in the warpage of 3D printed samples (from 27% to 7.6%). Rheological and morphological analyses confirmed good miscibility and uniform phase distribution in the blends, with increasing LLDPE content enhancing complex viscosity and melt elasticity. Overall, the rHDPE/LLDPE blends exhibit superior mechanical performance and reduced warpage, establishing their potential for FFF 3D printing applications.</p>
10aCrystallization10aFFF 3D printing10ahigh-density polyethylene blends10aRecycling10atoughness10awarpage1 aGopal, Animesh1 aChaubal, Aman1 aShanmuganathan, Kadhiravan  uhttps://library.ncl.res.in/content/low-warping-and-high-toughness-recycled-high-density-polyethylene-fused-filament-fabrication