1 Rajak, K. (2020). COVID-19 crisis prompting innovation in addressing personal protective equipment shortage. Journal of Patan Academy of Health Sciences, 7(1), 69-72. http://doi.org/10.3126/jpahs.v7i1.28867.

2 Cohen, J., & Rodgers, Y. V. D. M. (2020). Contributing factors to personal protective equipment shortages during the COVID-19 pandemic. Preventive Medicine, 141, 106263. http://doi.org/10.1016/j.ypmed.2020.106263. PMid:33017601.

3 Fischer, E. P., Fischer, M. C., Grass, D., Henrion, I., Warren, W. S., & Westman, E. (2020). Low-cost measurement of face mask efficacy for filtering expelled droplets during speech. Science Advances, 6(36), eabd3083. http://doi.org/10.1126/sciadv.abd3083. PMid:32917603.

4 Raurell-Torredà, M., Martínez-Estalella, G., Frade-Mera, M. J., Rodríguez-Rey, L. F. C., & San Pío, E. R. (2020). Reflections arising from the COVID-19 pandemic. Enfermeria Intensiva, 31(2), 90-93. http://doi.org/10.1016/j.enfie.2020.03.001. PMid:32284182.

5 Pathak, V. M., & Navneet, (2017). Review on the current status of polymer degradation: a microbial approach. Bioresources and Bioprocessing, 4(1), 15. http://doi.org/10.1186/s40643-017-0145-9.

6 D’Amato, G., Cecchi, L., D’Amato, M., & Annesi-Maesano, I. (2014). Climate change and respiratory diseases. European Respiratory Review, 23(132), 161-169. http://doi.org/10.1183/09059180.00001714. PMid:24881071.

7 Tekade, R. R., & Vidhale, S. G. (2023). Advancement in polymer blends and composites: a comprehensive review of structural, optical, thermal and electrical attributes for multifaceted Applications. Journal of Propulsion Technology, 44(4), 7190-7201. http://doi.org/10.52783/tjjpt.v44.i4.2554.

8 Dorigato, A. (2021). Recycling of polymer blends. Advanced Industrial and Engineering Polymer Research, 4(2), 53-69. http://doi.org/10.1016/j.aiepr.2021.02.005.

9 Yousaf, A., Al Rashid, A., Polat, R., & Koç, M. (2024). Potential and challenges of recycled polymer plastics and natural waste materials for additive manufacturing. Sustainable Materials and Technologies, 41, e01103. http://doi.org/10.1016/j.susmat.2024.e01103.

10 Silva, R. N., Santos, A. R., Patrício, P. S. O., & Fontes, W. C. (2024). Development and analysis of artificial ornamental stone with industrial wastes and epoxy resin. Sustainability, 16(17), 7715. http://doi.org/10.3390/su16177715.

11 Pan, D., Su, F., Liu, C., & Guo, Z. (2020). Research progress for plastic waste management and manufacture of value-added products. Advanced Composites and Hybrid Materials, 3(4), 443-461. http://doi.org/10.1007/s42114-020-00190-0.

12 Begum, S. A., Rane, A. V., & Kanny, K. (2020). Applications of compatibilized polymer blends in automobile industry. In A. A. Ajitha & S. Thomas (Eds.), Compatibilization of polymer blends: micro and nano scale phase morphologies, interphase characterization and properties (Chap. 20, pp. 563-593). Netherlands: Elsevier. http://doi.org/10.1016/B978-0-12-816006-0.00020-7.

13 Hou, X., Chen, S., Koh, J. J., Kong, J., Zhang, Y.-W., Yeo, J. C. C., Chen, H., & He, C. (2021). Entropy-driven ultratough blends from brittle polymers. ACS Macro Letters, 10(4), 406-411. http://doi.org/10.1021/acsmacrolett.0c00844. PMid:35549235.

14 Ferreira, T., Mendes, G. A., de Oliveira, A. M., & Dias, C. G. B. T. (2022). Manufacture and characterization of Polypropylene (PP) and High-Density Polyethylene (HDPE) blocks for potential use as masonry component in civil construction. Polymers, 14(12), 2463. http://doi.org/10.3390/polym14122463. PMid:35746039.

15 Huang, W., Wang, K., Tu, C., Xu, X., Tian, Q., Ma, C., Fu, Q., & Yan, W. (2022). Synergistic effects of DOPO-based derivative and organo-montmorillonite on flame retardancy, thermal stability and mechanical properties of polypropylene. Polymers, 14(12), 2372. http://doi.org/10.3390/polym14122372. PMid:35745948.

16 Matias, Á. A., Lima, M. S., Pereira, J., Pereira, P., Barros, R., Coelho, J. F. J., & Serra, A. C. (2020). Use of recycled polypropylene/poly (ethylene terephthalate) blends to manufacture water pipes: an industrial scale study. Waste Management, 101, 250-258. http://doi.org/10.1016/j.wasman.2019.10.001. PMid:31634811.

17 Velásquez, E. J., Garrido, L., Guarda, A., Galotto, M. J., & López de Dicastillo, C. (2019). Increasing the incorporation of recycled PET on polymeric blends through the reinforcement with commercial nanoclays. Applied Clay Science, 180, 105185. http://doi.org/10.1016/j.clay.2019.105185.

18 Koh, J. J., Zhang, X., & He, C. (2018). Fully biodegradable Poly(lactic acid)/Starch blends: a review of toughening strategies. International Journal of Biological Macromolecules, 109, 99-113. http://doi.org/10.1016/j.ijbiomac.2017.12.048. PMid:29248552.

19 Chen, R. S., Ab Ghani, M. H., Salleh, M. N., Ahmad, S., & Gan, S. (2014). Influence of blend composition and compatibilizer on mechanical and morphological properties of recycled HDPE/PET blends. Materials Sciences and Applications, 5(13), 943-952. http://doi.org/10.4236/msa.2014.513096.

20 Fernandes, B. L., & Domingues, A. J. (2007). Caracterização mecânica de polipropileno reciclado para a indústria automotiva. Polímeros. Ciência e Tecnologia, 17(2), 85-87. http://doi.org/10.1590/S0104-14282007000200005.

21 Ohta, H., Tohno, H., & Uruji, T. (2002). Use of recycled plastic as truck and bus component material (Technical Review, No. 14). Tokyo: Mitsubishi Motors Corporation. Retrieved in 2024, June 12, from http://mmc-manuals.ru/manuals/misc/technical_review/technical_review_2002.pdf

22 Ladhari, A., Kucukpinar, E., Stoll, H., & Sängerlaub, S. (2021). Comparison of properties with relevance for the automotive sector in mechanically recycled and virgin polypropylene. Recycling, 6(4), 76. http://doi.org/10.3390/recycling6040076.

23 Santos, A. R., Silva, R. N., Santos, N. M., Vieira, M. F. C., Patrício, P. S. O., & Fontes, W. C. (2024). Production of a wood-plastic composite with wastes from disposable masks and corrugated cardboard: a sustainable post-pandemic approach. Sustainability, 16(22), 9726. http://doi.org/10.3390/su16229726.

24 Coura, I. R., Carmignano, O. R. D. R., Heitmann, A. P., Lameiras, F. S., Lago, R. M., & Patrício, P. S. O. (2021). Use of iron mine tailing as fillers to polyethylene. Scientific Reports, 11(1), 7091. http://doi.org/10.1038/s41598-021-86456-z. PMid:33782479.

25 Qiu, W., Zhang, F., Endo, T., & Hirotsu, T. (2003). Preparation and characteristics of composites of high-crystalline cellulose with polypropylene: effects of maleated polypropylene and cellulose content. Journal of Applied Polymer Science, 87(2), 337-345. http://doi.org/10.1002/app.11446.

26 Kim, H.-S., Lee, B.-H., Choi, S.-W., Kim, S., & Kim, H.-J. (2007). The effect of types of maleic anhydride-grafted polypropylene (MAPP) on the interfacial adhesion properties of bio-flour-filled polypropylene composites. Composites. Part A, Applied Science and Manufacturing, 38(6), 1473-1482. http://doi.org/10.1016/j.compositesa.2007.01.004.

27 Gabriel, D. S., & Tiana, A. N. (2020). Mechanical properties improvement of recycled polypropylene with material value conservation schemes using virgin plastic blends. Materials Science Forum, 1015, 76-81. http://doi.org/10.4028/www.scientific.net/MSF.1015.76.

28 Hyie, K. M., Budin, S., Martinus, N., Salleh, Z., & Masdek, N. R. N. (2019). Tensile and flexural investigation on polypropylene recycling. Journal of Physics: Conference Series, 1174, 012005. http://doi.org/10.1088/1742-6596/1174/1/012005.

29 Stoian, S. A., Gabor, A. R., Albu, A.-M., Nicolae, C. A., Raditoiu, V., & Panaitescu, D. M. (2019). Recycled polypropylene with improved thermal stability and melt processability. Journal of Thermal Analysis and Calorimetry, 138(4), 2469-2480. http://doi.org/10.1007/s10973-019-08824-2.

30 Braskem. (2017). Data sheet: polypropylene H 503. Retrieved in 2024, June 12, from https://www.braskem.com.br/busca-de-produtos?p=314

31 World Health Organization – WHO. (2020). Advice on the use of masks in the context of COVID-19: interim guidance. Geneva: WHO. Retrieved in 2024, June 12, from https://iris.who.int/handle/10665/332293

32 American Society for Testing and Materials – ASTM. (2014). ASTM D638-14: standard test method for tensile properties of plastics. West Conshohocken: ASTM.

33 American Society for Testing and Materials – ASTM. (2007). ASTM D790-07: standard test methods for flexural properties of unreinforced and reinforced plastics and electrical insulating materials. West Conshohocken: ASTM.

34 American Society for Testing and Materials – ASTM. (1998). ASTM D570-98: standard test method for water absorption of plastics. West Conshohocken: ASTM.

35 Lanyi, F. J., Wenzke, N., Kaschta, J., & Schubert, D. W. (2020). On the determination of the enthalpy of fusion of α-crystalline isotactic polypropylene using differential scanning calorimetry, X-ray diffraction, and fourier-transform infrared spectroscopy: an old story revisited. Advanced Engineering Materials, 22(9), 1900796. http://doi.org/10.1002/adem.201900796.

36 Traxler, I., Kaineder, H., & Fischer, J. (2023). Simultaneous modification of properties relevant to the processing and application of virgin and post-consumer polypropylene. Polymers, 15(7), 1717. http://doi.org/10.3390/polym15071717. PMid:37050331.

37 Tratzi, P., Giuliani, C., Torre, M., Tomassetti, L., Petrucci, R., Iannoni, A., Torre, L., Genova, S., Paolini, V., Petracchini, F., & Di Carlo, G. (2021). Effect of hard plastic waste on the quality of recycled polypropylene blends. Recycling, 6(3), 58. http://doi.org/10.3390/recycling6030058.

38 Zander, N. E., Gillan, M., Burckhard, Z., & Gardea, F. (2019). Recycled polypropylene blends as novel 3D printing materials. Additive Manufacturing, 25, 122-130. http://doi.org/10.1016/j.addma.2018.11.009.

39 Handayani, S. U., Fahrudin, M., Mangestiyono, W., & Muhamad, A. F. H. (2021). Mechanical properties of commercial recycled polypropylene from plastic waste. Journal of Vocational Studies on Applied Research, 3(1), 1-4. http://doi.org/10.14710/jvsar.v3i1.10868.

40 Bahlouli, N., Pessey, D., Raveyre, C., Guillet, J., Ahzi, S., Dahoun, A., & Hiver, J. M. (2012). Recycling effects on the rheological and thermomechanical properties of polypropylene-based composites. Materials & Design, 33, 451-458. http://doi.org/10.1016/j.matdes.2011.04.049.

41 Jones, H., McClements, J., Ray, D., Hindle, C. S., Kalloudis, M., & Koutsos, V. (2023). Thermomechanical properties of virgin and recycled polypropylene: high-density polyethylene blends. Polymers, 15(21), 4200. http://doi.org/10.3390/polym15214200. PMid:37959880.

42 Bernagozzi, G., Arrigo, R., Ponzielli, G., & Frache, A. (2024). Towards effective recycling routes for polypropylene: influence of a repair additive on flow characteristics and processability. Polymer Degradation & Stability, 223, 110714. http://doi.org/10.1016/j.polymdegradstab.2024.110714.

43 Mohamad, N., Abd Latiff, A., Abd Razak, J., Ab Maulod, H. E., Liew, P. J., Kasim, M. S., & Ahsan, Q. (2021). Morphological characteristics and wear mechanism of recycled carbon fibre prepreg reinforced polypropylene composites. Malaysian Journal on Composites Science and Manufacturing, 5(1), 1-10. http://doi.org/10.37934/mjcsm.5.1.110.

44 Caicedo, C., Vázquez-Arce, A. R., Ossa, O. H., De La Cruz, H., & Maciel-Cerda, A. (2018). Physicomechanical behavior of composites of polypropylene, and mineral fillers with different process cycles. Dyna, 85(207), 260-268. http://doi.org/10.15446/dyna.v85n207.71894.

45 Barbosa, L. G., Piaia, M., & Ceni, G. H. (2017). Analysis of impact and tensile properties of recycled polypropylene. International Journal of Materials Engineering, 7(6), 117-120. http://doi.org/10.5923/j.ijme.20170706.03.

46 Raj, M. M., Patel, H. V., Raj, L. M., & Patel, N. K. (2013). Studies on mechanical properties of recycled polypropylene blended with virgin polypropylene. International Journal of Science Innovations Today, 2(3), 194-203. Retrieved in 2024, June 12, from http://www.ijsit.com/admin/ijsit_files/STUDIES%20ON%20MECHANICAL%20PROPERTIES%20OF%20RECYCLED%20POLYPROPYLENE%20BLENDED%20WITH%20VIRGIN%20POLYPROPYLENE_IJSIT_2.3.3.pdf

47 Pantani, R., Sorrentino, A., Speranza, V., & Titomanlio, G. (2004). Molecular orientation in injection molding: experiments and analysis. Rheologica Acta, 43(2), 109-118. http://doi.org/10.1007/s00397-003-0325-8.

48 Sha, B., Dimov, S., Griffiths, C., & Packianather, M. S. (2007). Investigation of micro-injection moulding: factors affecting the replication quality. Journal of Materials Processing Technology, 183(2-3), 284-296. http://doi.org/10.1016/j.jmatprotec.2006.10.019.

49 Wang, K., Addiego, F., Bahlouli, N., Ahzi, S., Rémond, Y., & Toniazzo, V. (2014). Impact response of recycled polypropylene-based composites under a wide range of temperature: effect of filler content and recycling. Composites Science and Technology, 95, 89-99. http://doi.org/10.1016/j.compscitech.2014.02.014.

50 Mourad, A.-H. I. (2010). Thermo-mechanical characteristics of thermally aged polyethylene/polypropylene blends. Materials & Design, 31(2), 918-929. http://doi.org/10.1016/j.matdes.2009.07.031.

51 Luna, C. B. B., Silva, W. A., Araújo, E. M., Silva, L. J. M. D., Melo, J. B. D. C. A., & Wellen, R. M. R. (2022). From waste to potential reuse: mixtures of polypropylene/recycled copolymer polypropylene from industrial containers: seeking sustainable materials. Sustainability, 14(11), 6509. http://doi.org/10.3390/su14116509.