Fine grinding of thermoplastics by high speed friction grinding assisted by guar gum. Issue 32 (5th April 2021)

• Record Type: Journal Article
• Authors: Bhagia, Samarthya; Gallego, Nidia C.; Hiremath, Nitilaksha; Harper, David P.; Lowden, Richard A.; Lowden, Richard R.; Pu, Yunqiao; Vaidya, Uday; Ozcan, Soydan; Ragauskas, Arthur J.
• Is Part Of: Journal of applied polymer science. Volume 138:Issue 32(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-04-05
• Subjects: galactomannan -- grinding -- guar gum -- milling -- polylactic acid -- polyethylene -- polypropylene -- recycling -- thermoplastics; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.50797
• Languages: English
• ISSNs: 0021-8995

Abstract

Abstract: High speed friction grinding has been used to grind plant and food substances in water but never been explored for grinding of thermoplastics like polylactic acid (PLA), low and high density polyethylene and polypropylene. Such grinding was investigated in this work and was made possible by using 0.5% guar gum solution instead of just water because increasing the viscosity of water reduced their settling and the speed of passing through the grinder. Tensile, flexural, and impact strengths of the plastics were studied and higher grinding efficiency of PLA could be explained by its low elongation‐at‐break compared to low density polyethylene, high density polyethylene, and polypropylene. The microplastics (2000–45 μm) were studied for mass and particle size distributions and by scanning electron microscopy, 13 C CP/MAS NMR, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. In addition, viscosity of guar gum and contact angles was measured. This new technology can produce finely ground microplastics (710–45 μm) for a variety of applications. Abstract : High speed friction grinding has never been explored for grinding of plastics as they are highly hydrophobic and elastic in nature. This study examines a new concept involving use of food gums like guar gum for grinding of thermoplastics into finely ground particles in an environmental friendly and cost‐effective way. The finely ground thermoplastics have a variety of material science applications such as additive manufacturing, plastic coating on metal substrates, biomedical devices, and recycling.