Utilization of tire rubber and recycled polyolefins into thermoplastic elastomers
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One can see that the higher GTR content in TPEs the lower tensile properties of the product. Additional homogenization by rolling pre-heated GTR/bitumen blend and/or final product (cf. Table 11) further improved the tensile strength and, especially, ultimate elongation of the resulting TPEs. This fact evidences of an effective compatibilization of the TPE blend components [37]. Table 11. Tensile properties of individual polymers and blends produced. The data presented in the parentheses represent the properties after ageing at 70 oC for 24 hours. Blend code
B1 B2 B3 B4 B5 B6
B7 B8 B9 B10 B11
B12 B13 B14
B15 B16 B17 B18
a)
Composition
Code of Tensile Ultimate producing strength, elongation, % method MPa Mastication by using Brabender plasticorder
Hardness (Shore A)
Recipe “a” HDPE-pc/EPDM A 13.0 (20.0) 840 (754) HDPE-pc/EPDM/GTR A 4.4 (6.7) 114 (120) HDPE-pc/EPDM/ (GTR/bitumen) A 4.1 (6.5) 168 (176) B 4.9 (8.0) 528 (536) HDPE-pc/EPDM/ (GTR/bitumen) C 6.0 (10.2) 540 (535) HDPE-pc/EPDM/ (GTR/bitumen) HDPE-pc/EPDM/ D 6.1 (10.7) 615 (590) (GTR/bitumen) Recipe “b” HDPE-pc/EPDM A 11.6 (17.9) 750 (593) HDPE-pc/EPDM/ GTR A 3.7 (6.7) 46 (58) HDPE-pc/EPDM/ (GTR/bitumen) A 3.9 (7.0) 85 (97) B 4.0 (5.2) 127 (194) HDPE-pc/EPDM/ (GTR/bitumen) C 5.9 (5.3) 377 (325) HDPE-pc/EPDM/ (GTR/bitumen) Recipe “c” A 6.8 265 HDPE-pc/SBRa) A 7.0 18 HDPE-pc/SBRa)/GTR HDPE-pc/SBRa)/(GTR/bitumen) C 8.4 355 Mastication by using single-screw extruder Recipe “a” HDPE-pc /EPDM/ E 7.5 270 (GTR/bitumen) F 9.0 300 HDPE-pc /EPDM/ (GTR/bitumen) G 9.8 425 HDPE-pc /EPDM/ (GTR/bitumen) H 13.6 515 HDPE-pc /EPDM/ (GTR/bitumen)
Curing system used, phr per 100 phr of SBR in mix formulations: Sulfur 0.9; Tetramethyl thiuram disulfide 0.1 0.1; ZnO 5.0; Stearic acid 2.0; 2-mercaptobenzothiazole 1.0.
93 96 94 93 93 93
90 95 93 93 92
83 79 84
88 89 86 86