Page 55 - 《橡塑技术与装备》英文版2025年12月

MATERIALS AND FORMULATIONS

and chemical methods to desulfurize CR, aiming to utilize CR, HDA, and oil in a mass ratio of 20:1:3, and stir them
the strong shear and high temperature of the Haake mixer, as for 10 minutes at 500/min using a mixer. Then, add them
well as the selective de-crosslinking of HDA, to break the C-S to a Haake internal mixer and mix for 10 minutes to obtain
bond, S-S bond, disulfide bond, and polysulfide bond in CR. desulfurized rubber powder of different processes. The specific
By changing the temperature, speed, and HDA content of the desulfurization conditions are shown in Table 3.
Haake mixer, the degree of desulfurization of desulfurized Table 3 Desulfurization conditions for desulfurized
rubber powder (DCR) is analyzed to determine the optimal rubber powder from Hacker mixer
Rotational Speed
desulfurization process. After blending DCR with SBS to Temperature T/℃ -1 HDA Content H/g
R/(r.min )
produce composite modified asphalt (PMA), the influence of DCRT140R80H10 140 80 10
DCRT160R80H10 160 80 10
CR desulfurization process on asphalt performance is explored. DCRT180R80H10 180 80 10
DCRT160R40H10 160 40 10
DCRT160R60H10 160 60 10
1 Experimental part DCRT160R80H20 160 80 20
1.1 Raw materials DCRT160R80H30 160 80 30
Rubber powder (CR), purchased from Jiangsu
Zhonghong Environmental Protection Co., Ltd., is obtained Preparation of SBS/DCR composite modified asphalt:
First, mix DCR with ω(SBS)=2% and ω(SBS)=40% in a
by removing metal, textile, and other related impurities from
Haake mixer at 160℃ and 80/min for 10 minutes to obtain
tires, followed by crushing, grinding, and screening to obtain
rubber powder below 40 mesh. Its basic composition is shown the SBS/DCR composite. Then, preheat 90# base asphalt
in an oven at 120℃ for 30 minutes to melt it. Under an
in Table 1. Hexadecylamine (HDA) and carbon disulfide
environment at 200℃, slowly add 42% (mass fraction) of
(CS2), purchased from Macklin Biochemical Technology Co.,
Ltd. in Shanghai, China, are of HPLC 99.9% purity. Glycerol the SBS/DCR composite, stir at 1200 r/min for 2 hours,
and then shear at 5000 r/min for 1 hour. Finally, SBS/DCR
triglycidyl ether, used as a compatibilizer, is purchased from
composite modified asphalt is obtained, which is named
Macklin Biochemical Technology Co., Ltd. in Shanghai, with
a purity of 99.9%. Waste engine oil (oil) is purchased from PMAT140R80H10, PMAT160R80H10, PMAT180R80H10,
Shanxi Changhe Automobile Repair Factory. 90# matrix PMAT160R40H10, PMAT160R60H10, PMAT160R80H20,
and PMAT160R80H30.
asphalt, Kunlun asphalt, has its basic properties shown in Table
2. Linear SBS (trade name YH-791H (SBS1301-1)), purchased 1.3 Test method
from Sinopec Baling Petrochemical Co., Ltd., has a styrene- 1.3.1 Testing of DCR
butadiene mass ratio of 30:70. (1) Sol content test
The sol content was determined by Soxhlet extraction.
Table 1 Basic composition of 40 mesh CR
Indicator Test Results First, the sample (approximately 0.2 g) was extracted in
Operating oil/% 6.58 boiling acetone for 12 hours, then dried in a vacuum oven at
Rubber hydrocarbon/% 54.77
Carbon black / % 26.96 80 ℃ to remove the solvent until reaching constant weight,
Ash content /% 11.69 and the mass was measured (w 1 ). Subsequently, the sample was
extracted in boiling toluene for 12 hours. Finally, the sample
Table 2 Physical properties of 90# matrix asphalt
Indicator Test Results was dried in an oven at 80 ℃ until reaching constant weight,
Penetration/(25 ℃ ,0.1 mm) 85.7 and the mass was measured as (w 2 ). The sol content was
Softening point 44.5
Ductility / (5 ℃ , cm) 0 calculated using equation (1):
Elastic recovery/% 8.13 Sol content(%)= w 1 −w 2 ×10 (1)
Viscosity /(180 ℃ ,Pa·s) 0.12 w 1
(2) Crosslinking density test
The crosslinking density was determined by the
1.2 Sample preparation
Preparation of desulfurized rubber powder: Weigh equilibrium swelling method. Initially, the sample

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