Actionable insights into hazard mitigation of typical 3D printing waste via pyrolysis

• Published in: Journal of hazardous materials 2023-10, Vol.460, p.132414-132414, Article 132414
• Main Authors: Lin, Ziting, Liu, Jingyong, Cai, Haiming, Evrendilek, Fatih, Zhu, Chuanghai, Liang, Fanjin, Huang, Wenxiao, Li, Weixin, He, Chao, Yang, Chunxiao, Yang, Zuoyi, Zhong, Sheng, Xie, Wuming, He, Yao
• Format: Article
• Language: English
• Subjects: 3D printing waste; mass spectrometry; Master-plots method; phenol; photosensitivity; pollution; polyamides; Pyrolysis; pyrolysis gas chromatography; tetrahydrofuran; TG-FTIR-GC/MS; thermogravimetry; toluene; Volatile products; wastes
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2023.132414

3D printing waste (3DPW) contains hazardous substances, such as photosensitizers and pigments, and may cause environmental pollution when improperly disposed of. Pyrolysis treatment can reduce hazards and turn waste into useful resources. This study coupled thermogravimetric (TG), TG-Fourier transform infrared spectroscopy-gas chromatography/mass spectrometry, and rapid pyrolysis gas chromatography/mass spectrometry analysis to evaluate the pyrolytic reaction mechanisms, products, and possible decomposition pathways of the three typical 3DPW of photosensitive resin waste (PRW), polyamide waste (PAW), and polycaprolactone waste (PCLW). The main degradation stages of the typical 3DPW occurred at 320–580 °C. The most appropriate reaction mechanisms of PRW, PAW and PCLW were D1, A1.2 and A1.5, respectively. The main pyrolysis processes were the decomposition of the complex organic polymers of PRW, the breaking of the NH–CH2 bond and dehydration of –CO–NH– of PAW, and the breaking and reorganization of the molecular chains of PCLW, mainly resulting in toluene (C7H8), undecylenitrile (C11H21N), tetrahydrofuran (C4H8O), respectively. Unlike the slow pyrolysis, the rapid pyrolysis produced volatiles consisting mainly of phenol, 4,4'-(1-methylethylidene)bis- (C15H16O2) for PRW; 1,10-dicyanodecane (C12H20N2) for PAW; and ɛ-caprolactone (C6H10O2) for PCLW. These pyrolysis products hold great potential for applications. The findings of the study offer actionable insights into the hazard reduction and resource recovery of 3D printing waste. [Display omitted] •3D printing waste (3DPW) contains hazardous photosensitizers, pigments and so on.•Pyrolysis is an approach to reduce the hazards of 3DPW and produce value-added chemicals.•Pyrolysis stages and mechanisms of 3DPW were characterized.•Slow and rapid pyrolytic volatiles of 3DPW were determined.•Energetically optimal pyrolysis of 3DPW was quantified with ANN.