Title: 3D Printing of Recycled Polymer Composites from Mixed Polyolefin Blends and Nanoadditives

Authors: Siddhesh Chaudhari, Prudhvi Raj Pola, Jack Seiler, Tyler Meadows, Shihab Shakur, Anuj Maheshwari, Frank Blum, Sri Ramesh and Ranji Vaidyanathan

DOI: 10.33599/nasampe/c.24.0360

Abstract: Plastics have become a regular staple of our everyday lives, and while they are convenient, they also have an undesirable effect on the environment. When plastic waste is deposited into the municipal solid waste (MSW) stream, it does not easily degrade. Recycling must be efficient without compromising the recycled material’s properties to reduce their environmental impact. Current recycling methods require the different types of plastic (#1 – 7) to be sorted to maintain the polymer’s uniform material properties. While recent strides have been taken to automate plastic waste sorting, this can be costly and is only recycled between 15 and 21%. By investigating the 3D printing of recycled polymer composites, we aim to reduce the environmental impact of plastic waste significantly. The research presented investigates the viability of recycling different types of post-consumer polyolefins, such as high-density polyethylene (HDPE) and polypropylene (PP), without separating various polymers. Finding ways to optimize the recycling process and discovering new uses for a resulting material with decent material properties could help decrease the environmental damage of excessive plastic waste. Recycled HDPE and PP were blended in varying amounts with a compatibilizer and graphene oxide additive as a filament feedstock for additive manufacturing. By varying the ratios of recycled HDPE (rHDPE) and recycled PP (rPP) with a compatibilizer and graphene oxide (GO) powder in concentrations ranging from 0% to 2% by weight. Polymer blends were extruded through an extruder to form filaments. Changes in material characteristics such as tensile strength, tensile modulus, storage modulus, and glass transition temperature were measured. Both single filament and 3D printed samples (using an extrusion-based 3D printer) were tested in tension using ASTM D638 standard. The specific total fracture energy was calculated by determining the area under the force-displacement curve up to the maximum force and normalizing this value by the specimen's actual gauge volume. Combinations of HDPE and PP with graphene oxide were found to have comparable tensile strength as recycled HDPE and PP with improved strain to failure at ~0.1% GO addition. Higher GO concentrations were found to reduce the tensile strength and crystallinity due to noticeable agglomeration.

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Conference: CAMX 2024 | San Diego CA

Publication Date: 2024/9/9

SKU: TP24-0000000360

Pages: 13

Price: $26.00