IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 18, Issue 2 Ser. II (Mar. – Apr. 2021), PP 50-56 www.iosrjournals.org DOI: 10.9790/1684-1802025056 www.iosrjournals.org 50 | Page Characterization of virgin Poly(butylene Terephthalate) and recycled Poly(butylene Terephthalate) from toothbrush bristles Nga Thi-Hong Pham 1 1 (Mechanical Engineering Faculty, HCMC University of Technology and Education, 1 Vo Van Ngan st., Thu Duc district, HCM City, 71307, Vietnam) Abstract: Background: Recycling engineering plastics has been a hot topic that has received a lot of attention. Poly (butylene terephthalate) (PBT) is a brittle material that is generally not suitable for certain applications, while the source of toothbrush bristles recycling is enormous. Research on recycled materials not only has a positive impact on the environment but also can reduce material costs by using recycled materials. Materials and Methods: In this research, blends of recycling PBT, which comes from PBT toothbrush bristles, and origin PBT were researched. Tensile strength, flexural strength, Charpy impact testing are studied according to ASTM D638, ASTM D790, and ASTM D256 standard. The samples then were measured through SHORE hardness measurement methods according to ASTM D2240 and microstructure is observed by using a high-resolution FESEM microscope. Results: The virgin PBT and R-PBT are very brittle, the fracture mechanism of these samples is also brittle fracture. The average tensile strength of R-PBT samples was significantly higher than the PBT samples. However, the tensile elastic, flexural elastic, and impact strength of PBT are higher than that of R-PBT sample. About microstructure, virgin PBT sample and R-PBT sample show white particles. No crack initiation area was observed on the fracture surface and no crack propagation was investigated in an unstable way. PBT sample has a smoother organization than R-PBT sample. Conclusion: recycled blends showed to have competitive mechanical properties compared to virgin materials Key Word: Poly (butylene terephthalate), Recycling Poly(butylene Terephthalate), Microstructure, Tensile strength, Flexural strength. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 22-03-2021 Date of Acceptance: 06-04-2021 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction In recent decades, plastic recycling has been a hot topic that has received a lot of attention, especially recycling engineering plastics [1-3]. The environmental troubles caused by polymer waste have prompted actions to reuse and recycle those materials [4-6]. Some methods are applied in polymer recycling technology such as depolymerization, burning polymers for energy recovery, mechanical recycling... In which mechanical recycling has more advantages. However, the degradation of the material is one of the major problems with this polymer recycling method [7-9]. Author Miguel Jorge Reig [10] researches recycled ABS/recycled PC blend. The results showed that the inclusion of the PC in the blend caused the viscosity difference, which was greater as the higher the PC content. Viscosity correction with proposed correction is valid when compared with tested blends of recycled materials. Paul Miller [11] elaborated recycling HDPE with 8 different virgin polyolefins. The results showed that long-chain mixes, such as film blowing grade materials, showed significant variation in viscosity ratio compared to long-chain blends, such as injection molding grade materials. Li Sheng [12] analyzed PE special material for pipe, recycled PE, PE/recycled PE blends, and pipe products, found an easy strategy to define PE/recycled PE blends by assessing Fe and Ca content. In addition, many scientists also add compatibilizers to the recycling mix. Gregor Radonjic [13] used EPR as a compatibilizer to blend recycled LDPE/PP 80/20 and recycled HDPE/PP 80/20 blends. With the addition of EPR, the notched impact strength and elongation at yield of the recycled LDPE/PP 80/20 blend were significantly improved and Young's modulus and elongation at yield improved slightly. Notched impact strength of recycling HDPE/PP 80/20 blend has been improved to some extent. Xiaodong Liu [14] studied four different plastics from scrapped Volvo cars. They are ABS and ABS/PC, PMMA and PA. Blending recycled ABS and PC/ABS (70/30) with a small amount of methyl methacrylate-butadiene-styrene core-shell impact modifiers has better properties than any of their individual ingredients. Approximately 10% PMMA from the rear light cover can conform to PC/ABS blends made. Property profile will be improved. Studies of recycled polymers show that the chemical structure, melting temperature, and thermal properties of the whole primary mix change negligibly when recycled. In the study of Emel Kuram [15],