Please wait a minute...
Frontiers of Environmental Science & Engineering

ISSN 2095-2201

ISSN 2095-221X(Online)

CN 10-1013/X

Postal Subscription Code 80-973

2018 Impact Factor: 3.883

Front. Environ. Sci. Eng.    2017, Vol. 11 Issue (5) : 4
Recycling polymeric waste from electronic and automotive sectors into value added products
Abhishek Kumar1, Veena Choudhary1, Rita Khanna2(), Romina Cayumil2, Muhammad Ikram-ul-Haq2, Veena Sahajwalla2, Shiva Kumar I. Angadi3, Ganapathy E. Paruthy3, Partha S. Mukherjee3, Miles Park4
1. Centre for Polymer Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas New Delhi 110016, India
2. Centre for Sustainable Materials Research and Technology (SMaRT), School of Materials Science and Engineering, The University of New South Wales, Sydney NSW 2052, Australia
3. CSIR- Institute of Minerals and Materials Technology, Advanced Materials Technology Department, Bhubaneshwar, Orissa 751013, India
4. Industrial Design, Australian School of Architecture and Design, The University of New South Wales, Sydney NSW 2052, Australia
 Download: PDF(350 KB)   HTML
 Export: BibTeX | EndNote | Reference Manager | ProCite | RefWorks

• Polymer fraction was separated from waste PCBs by froth floatation.

• Addition of waste PCBs to polypropylene reduced the overall impact strength.

• Up to 9 wt.% rubber was added to PP/25 wt.% PCB composites as impact modifier.

• Mechanical, structural, rheological properties of composites were investigated.

• Electronic and automotive waste were successfully utilized in PP composites.

The environmentally sustainable disposal and recycling of ever increasing volumes of electronic waste has become global waste management issue. The addition of up to 25% polymeric waste PCBs (printed circuit boards) as fillers in polypropylene (PP) composites was partially successful: while the tensile modulus, flexural strength and flexural modulus of composites were enhanced, the tensile and impact strengths were found to decrease. As a lowering of impact strength can significantly limit the application of PP based composites, it is necessary to incorporate impact modifying polymers such as rubbery particles in the mix. We report on a novel investigation on the simultaneous utilization of electronic and automotive rubber waste as fillers in PP composites. These composites were prepared by using 25 wt.% polymeric PCB powder, up to 9% of ethylene propylene rubber (EPR), and PP: balance. The influence of EPR on the structural, thermal, mechanical and rheological properties of PP/PCB/EPR composites was investigated. While the addition of EPR caused the nucleation of the β crystalline phase of PP, the onset temperature for thermal degradation was found to decrease by 8%. The tensile modulus and strength decreased by 16% and 19%, respectively; and the elongation at break increased by ~71%. The impact strength showed a maximum increase of ~18% at 7 wt.%–9 wt.% EPR content. Various rheological properties were found to be well within the range of processing limits. This novel eco-friendly approach could help utilize significant amounts of polymeric electronic and automotive waste for fabricating valuable polymer composites.

Keywords E-waste      Polymer composites      Recycling      Rubber      Waste PCBs      Filler     
Corresponding Authors: Rita Khanna   
Issue Date: 08 September 2017
 Cite this article:   
Abhishek Kumar,Veena Choudhary,Rita Khanna, et al. Recycling polymeric waste from electronic and automotive sectors into value added products[J]. Front. Environ. Sci. Eng., 2017, 11(5): 4.
Basic characteristics Property Value
(a) Polypropylene (REPOL H110MA, Reliance Industries Limited, India) Melt Flow Index (230°C/2.16 kg) 11 g/10 min
Tensile strength at yield (50 mm/min) 36 MPa
Elongation at yield (50 mm/min) 10%
Flexural modulus (1% secant) 1650 MPa
Notched izod impact strength (23°C) 27 J/m
Heat deflection temperature (455 kPa) 104°C
(b) Ethylene propylene rubber EPR (Vistamaxx 6202, ExxonMobil Chemical) Density 0.863 g/cm 3
Melt Flow Index (190°C, 2.16 kg) 9.1 g/10 min
Ethylene content 15%
Durometer Hardness (Shore A, 15 s) 66
Flexural Modulus (1% secant) 1780 psi
Tensile set 18%
Tab.1  Basic characteristics of (a) polypropylene (PP), and (b) ethylene propylene rubber (EPR)
Fig.1  X-ray diffractograms of PPE-X waste composites
Fig.2  DSC scans during (a) the cooling and (b) the heating of PPE-X waste composites
Sample name Melting temperature (°C) Crystallization onset
temperature (°C)
Crystallization peak temperature (°C) Melting enthalpy DHf (J/g) Crystallinity X c (%)
PPE-0 164.6 131.1 127.3 94.5 60.1
PPE-3 164.7 130.8 126.9 87.9 58.0
PPE-5 164.0 131.0 127.2 89.7 60.1
PPE-7 164.5 131.0 127.3 84.3 58.4
PPE-9 164.6 130.9 127.7 84.0 59.5
Tab.2  (a) DSC analysis of PPE-X waste composites
Sample name Step I degradation (°C) Step II degradation (°C)
Onset End Inflection point Onset End Inflection point
PPE-0 326.7 374.7 348.1 442.7 478.6 465.3
PPE-3 318.6 365.9 343.7 441.4 480.1 467.8
PPE-5 322.2 366.0 346.2 441.7 480.5 466.3
PPE-7 319.9 365.7 348.9 442.3 482.0 470.2
PPE-9 322.2 369.7 347.9 441.2 479.4 466.4
Tab.3  (b) Thermo-gravimetric analysis of PPE-X waste composites
Sample name Tensile modulus (MPa) Tensile strength (MPa) Elongation at break (%) Impact strength (kJ/m 2)
PPE-0 299.9±9.5 30.3±0.5 18.1±2.3 2.31±0.23
PPE-3 299.9±17.8 29.5±0.7 19.0±1.5 2.38±0.11
PPE-5 269.7±17.3 25.5±0.1 20.9±4.2 2.44±0.27
PPE-7 271.0±13.0 24.2±0.6 24.5±2.9 2.54±0.12
PPE-9 253.8±11.6 24.0±0.8 30.9±1.8 2.53±0.18
Tab.4  Mechanical properties of PPE-X waste composites
Fig.3  Effect of EPR addition on (a) the tensile modulus, and (b) the tensile strength and strain at break of PPE-X waste composites
Fig.4  (a) Effect of EPR content on the impact strengths of PPE-X waste composites, and (b) SEM images of cryo-fractured surfaces of PPE-9 waste composites
Fig.5  (a) Elastic modulus (G’), (b) Viscous modulus (G”) and (c) Complex viscosity (|h*|) of PPE-X waste composites as a function of frequency (f) at 220°C
1 Baldé C P ,  Wang F, Kuehr  R, Huisman J . The Global E-Waste Monitor- 2014. Bonn, Germany: United Nations University, IAS- SCYCLE, 2014, 1
2 Cayumil R, Khanna  R, Ikram-Ul-Haq M ,  Rajarao R ,  Hill A, Sahajwalla  V. Generation of copper rich metallic phases from waste printed circuit boards. Waste Management (New York, N.Y.), 2015, 34(10): 1783–1792
3 Shen C, Chen  Y, Huang S ,  Wang Z, Yu  C, Qiao M ,  Xu Y, Setty  K, Zhang J ,  Zhu Y, Lin  Q. Dioxin-like compounds in agricultural soils near e-waste recycling sites from Taizhou area, China: Chemical and bioanalytical characterization. Environment International, 2009, 35(1): 50–55
4 Widmer R, Oswald-Krapf  H, Sinha-Khetriwal D ,  Schnellmann M ,  Böni H . Global perspectives on e-waste. Environmental Impact Assessment Review, 2005, 25(5): 436–458
5 Kasper A, Berselli  G, Freitas B ,  Tenório J ,  Bernardes A ,  Veit H. Printed wiring boards for mobile phones: Characterization and recycling of copper. Waste Management (New York, N.Y.), 2011, 31(12): 2536–2545
6 Cayumil R, Khanna  R, Rajarao R ,  Mukherjee P S ,  Sahajwalla V . Concentration of precious metals during their recovery from electronic waste. Waste Management (New York, N.Y.), 2016, 57: 121–130
7 Arshadi M, Mousavi  S M. Enhancement of simultaneous gold and copper extraction from computer printed circuit boards using Bacillus megaterium. Bioresource Technology, 2015, 175: 315–324
8 Bigum M, Brogaard  L, Christensen T H . Metal recovery from high-grade WEEE: A life cycle assessment. Journal of Hazardous Materials, 2012, 207: 8–14
9 Guo J, Tang  Y, Xu Z . Wood plastic composite produced by nonmetals from pulverized waste printed circuit boards. Environmental Science & Technology, 2009, 44(1): 463–468
10 Hall W J, Williams  P T. Separation and recovery of materials from scrap printed circuit boards. Resources, Conservation and Recycling, 2007, 51(3): 691–709
11 Hopewell J, Dvorak  R, Kosior E . Plastics recycling: challenges and opportunities. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 2009, 364(1526): 2115–2126
12 Dodds J, Domenico  W, Evans D ,  Fish L, Lassahn  P, Toth W . Scrap Tires: A Resource and Technology Evaluation of Tire Pyrolysis and Other Selected Alternate Technologies. Washington, DC: US Department of Energy, 1983
13 Zaharia M, Sahajwalla  V, Kim B C ,  Khanna R ,  Saha-Chaudhury N ,  O’Kane P ,  Dicker J ,  Skidmore C ,  Knights D . Recycling of rubber tires in electric arc furnace steelmaking: Simultaneous combustion of metallurgical coke and rubber tyres blends. Energy & Fuels, 2009, 23(5): 2467–2474
14 Igwe I O, Ejim  A A. Studies on mechanical and end-use properties of natural rubber filled with snail shell powder. Materials Sciences and Applications, 2011, 2(07): 801–809
15 Eldin N N, Senouci  A B. Rubber-tire particles as concrete aggregate. Journal of Materials in Civil Engineering, 1993, 5(4): 478–496
16 Al-Salem S M, Lettieri  P, Baeyens J . Recycling and recovery routes of plastic solid waste (PSW): A review. Waste Management (New York, N.Y.), 2009, 29(10): 2625–2643
17 Sahajwalla V, Cayumil  R, Khanna R ,  Ikram-Ul-Haq M ,  Rajarao R ,  Mukherjee P S ,  Hill A. Recycling polymer-rich waste printed circuit boards at high temperatures: Recovery of value-added carbon resources. Journal of Sustainable Metallurgy, 2015, 1(1): 75–84
18 Guo Q, Yue  X, Wang M ,  Liu Y. Pyrolysis of scrap printed circuit board plastic particles in a fluidized bed. Powder Technology, 2010, 198(3): 422–428
19 Zhou Y, Qiu  K. A new technology for recycling materials from waste printed circuit boards. Journal of Hazardous Materials, 2010, 175(1–3): 823–828
20 Zhou Y, Wu  W, Qiu K . Recycling of organic materials and solder from waste printed circuit boards by vacuum pyrolysis-centrifugation coupling technology. Waste Management (New York, N.Y.), 2011, 31(12): 2569–2576
21 Khanna R, Ikram-Ul-Haq  M, Cayumil R ,  Rajarao R ,  Sahajwalla V . Novel carbon micro fibers and foams from waste printed circuit boards. Fuel Processing Technology, 2015, 134(473): 473–479
22 Mou P, Xiang  D, Duan G . Products made from nonmetallic materials reclaimed from waste printed circuit boards. Tsinghua Science and Technology, 2007, 12(3): 276–283
23 Guo J, Li  Q J, Rao Z ,  Xu. Phenolic molding compound filled with nonmetals of waste PCBs. Environmental Science & Technology, 2007, 42(2): 624–628
24 Guo J, Rao  Q, Xu Z . Application of glass-nonmetals of waste printed circuit boards to produce phenolic moulding compound. Journal of Hazardous Materials, 2007, 153(1–2): 728
25 Zheng Y, Shen  Z, Cai C ,  Ma S, Xing  Y. The reuse of nonmetals recycled from waste printed circuit boards as reinforcing fillers in the polypropylene composites. Journal of Hazardous Materials, 2009, 163(2–3): 600–606
26 Wang X, Guo  Y, Liu J ,  Qiao Q, Liang  J. PVC-based composite material containing recycled non-metallic printed circuit board (PCB) powders. Journal of Environmental Management, 2010, 91(12): 2505–2510
27 Peijs T. Composites for recyclability. Materials Today, 2003, 6(4): 30–35
28 Kumar A, Choudhary  V, Khanna R ,  Cayumil R ,  Ikram-ul-Haq M ,  Mukherjee P S ,  Sahajwalla V . Polymer composites utilizing electronic waste as reinforcing fillers: mechanical and rheological properties. Current Applied Polymer Science, 2016, 1(1): 1
29 Premalal H G B ,  Ismail H ,  Bahrain A . Comparison of the mechanical properties of rice husk powder filled polypropylene composites with talc filled polypropylene composites. Polymer Testing, 2002, 21(7): 833–839
30 Matsuda Y, Hara  M, Mano T ,  Okamoto K ,  Ishikawa M . Effect of the compatibility on toughness of injection‐molded polypropylene blended with EPR and SEBS. Polymer Engineering and Science, 2006, 46(1): 29–38
31 Wahit M U, Hassan  A, Ishak Z A M ,  Rahmat A R ,  Othman N . The effect of rubber type and rubber functionality on the morphological and mechanical properties of rubber-toughened polyamide 6/polypropylene nanocomposites. Polymer Journal, 2006, 38(8): 767–780
32 Tordjeman P, Robert  C, Marin G ,  Gerard P . The effect of α, β crystalline structures on the mechanical properties of polypropylene. European Physical Journal E, 2001, 4(4): 459–465
33 Grein C, Gahleitner  M. On the influence of nucleation on the toughness of iPP/EPR blends with different rubber molecular architectures. Express Polymer Letters, 2008, 2(6): 392–397
34 Ehsani M, Borsi  H, Gockenbach E ,  Morshedian J ,  Bakhshandeh G R . An investigation of dynamic mechanical, thermal, and electrical properties of housing materials for outdoor polymeric insulators. European Polymer Journal, 2008, 40(11): 2495–2503
35 Liang J Z, Li  R K Y. Rubber toughening in polypropylene: A review. Journal of Applied Polymer Science, 2000, 77(2): 409–417<409::AID-APP18>3.0.CO;2-N
[1] Biswajit Debnath, Ranjana Chowdhury, Sadhan Kumar Ghosh. Sustainability of metal recovery from E-waste[J]. Front. Environ. Sci. Eng., 2018, 12(6): 2-.
[2] Weihua Zhao, Meixiang Wang, Jianwei Li, Yu Huang, Baikun Li, Cong Pan, Xiyao Li, Yongzhen Peng. Optimization of denitrifying phosphorus removal in a pre-denitrification anaerobic/anoxic/post-aeration+ nitrification sequence batch reactor (pre-A2NSBR) system: Nitrate recycling, carbon/nitrogen ratio and carbon source type[J]. Front. Environ. Sci. Eng., 2018, 12(5): 8-.
[3] Zechong Guo, Lei Gao, Ling Wang, Wenzong Liu, Aijie Wang. Enhanced methane recovery and exoelectrogen-methanogen evolution from low-strength wastewater in an up-flow biofilm reactor with conductive granular graphite fillers[J]. Front. Environ. Sci. Eng., 2018, 12(4): 13-.
[4] Hyunhee Kim, Yong-Chul Jang, Yeonjung Hwang, Youngjae Ko, Hyunmyeong Yun. End-of-life batteries management and material flow analysis in South Korea[J]. Front. Environ. Sci. Eng., 2018, 12(3): 3-.
[5] Mengmeng Wang, Quanyin Tan, Joseph F. Chiang, Jinhui Li. Recovery of rare and precious metals from urban mines—A review[J]. Front. Environ. Sci. Eng., 2017, 11(5): 1-.
[6] Evangelia C. Vouvoudi, Aristea T. Rousi, Dimitris S. Achilias. Thermal degradation characteristics and products obtained after pyrolysis of specific polymers found in Waste Electrical and Electronic Equipment[J]. Front. Environ. Sci. Eng., 2017, 11(5): 9-.
[7] Xiaolong Song, Jingwei Wang, Jianxin Yang, Bin Lu. An updated review and conceptual model for optimizing WEEE management in China from a life cycle perspective[J]. Front. Environ. Sci. Eng., 2017, 11(5): 3-.
[8] Zebing Wu, Wenyi Yuan, Jinhui Li, Xiaoyan Wang, Lili Liu, Jingwei Wang. A critical review on the recycling of copper and precious metals from waste printed circuit boards using hydrometallurgy[J]. Front. Environ. Sci. Eng., 2017, 11(5): 8-.
[9] Paul Vanegas, Jef R. Peeters, Dirk Cattrysse, Wim Dewulf, Joost R. Duflou. Improvement potential of today’s WEEE recycling performance: The case of LCD TVs in Belgium[J]. Front. Environ. Sci. Eng., 2017, 11(5): 13-.
[10] John C. Radcliffe, Declan Page, Bruce Naumann, Peter Dillon. Fifty Years of Water Sensitive Urban Design, Salisbury, South Australia[J]. Front. Environ. Sci. Eng., 2017, 11(4): 7-.
[11] Ahmad Kalbasi Ashtari, Amir M. Samani Majd, Gerald L. Riskowski, Saqib Mukhtar, Lingying Zhao. Removing ammonia from air with a constant pH, slightly acidic water spray wet scrubber using recycled scrubbing solution[J]. Front. Environ. Sci. Eng., 2016, 10(6): 3-.
[12] Liangliang WEI,Kun WANG,Xiangjuan KONG,Guangyi LIU,Shuang CUI,Qingliang ZHAO,Fuyi CUI. Application of ultra-sonication, acid precipitation and membrane filtration for co-recovery of protein and humic acid from sewage sludge[J]. Front. Environ. Sci. Eng., 2016, 10(2): 327-335.
[13] Dongdong MA,Hongwen GAO. Reuse of heavy metal-accumulating Cynondon dactylon in remediation of water contaminated by heavy metals[J]. Front. Environ. Sci. Eng., 2014, 8(6): 952-959.
[14] Xianlai ZENG,Jinhui LI. Spent rechargeable lithium batteries in e-waste: composition and its implications[J]. Front.Environ.Sci.Eng., 2014, 8(5): 792-796.
[15] Minmin LIU,Ying ZHAO,Beidou XI,Li’an HOU,Xunfeng XIA. Performance of a hybrid anaerobic-contact oxidation biofilm baffled reactor for the treatment of decentralized molasses wastewater[J]. Front.Environ.Sci.Eng., 2014, 8(4): 598-606.
Full text