Effect of long aramid fiber on the properties of styrene‐butadiene rubber composites based on extrusion

Abstract

In this paper, long aramid fiber (LAF) reinforced styrene-butadiene rubber/ carbon black composites was prepared via a high pressure and low shear rate extrusion process, and the average length of the remaining fiber exceeded 6 mm. With LAF as reinforcement phase, the bonding between the fiber coated with butadiene styrene vinyl-pyridine rubber latex and rubber matrix was increased. The results showed that the addition of LAF improved the properties of the composites, particularly in terms of dynamic fatigue life of the notched samples, which was increased by 352.7%. The long fibers with good interfacial bonding were peeled off in fatigue process, which can significantly absorb strain energy; thus, the propagation of fatigue cracks was effectively inhibited. This study proposes a feasible strategy to significantly improve the service life of rubber products under alternating stress, such as tires, by using the reinforcement of long fiber.

Fatigue‐crack‐propagation behavior and mechanism of long hemp‐fiber‐enhanced styrene–butadiene rubber/carbon black compounds

“…As observed in the figure, the E ′ numerical value of SBR/CB/HF‐V‐E is the maximum. This is owing to the formation of good interface bonding between the long HFs and the SBR molecular chain in the SBR matrix after being coated with VPL as well as the higher number of bonding sites between the long fibers and SBR chains, which makes the relative‐displacement between the fibers and SBR chains more restrictive 47 …”

“…This is owing to the formation of good interface bonding between the long HFs and the SBR molecular chain in the SBR matrix after being coated with VPL as well as the higher number of bonding sites between the long fibers and SBR chains, which makes the relative-displacement between the fibers and SBR chains more restrictive. 47 The curve of the loss modulus (E 00 ) versus temperature is shown in Figure 5B. Under the extrusion process, the long HF coated with VPL-reinforced SBR exhibited a higher loss modulus.…”

“…44,50 The peak values of tanδ in SBR/CB/HF-V and SBR/CB/HF-V-E are lower, confirming that the flexible interfacial layer produced by the VPL coating can evidently upgrade the interfacial-bonding effect between fiber and rubber. 47,51 Figure 5C displays that the SBR/CB/HF-V-E compounds prepared by the low-shear and high-pressure extrusion process had the lowest loss factor and lower glass transition temperature. This is because the combination of long fibers and flexible VPL coating conferred better binding sites between fiber and rubber, indicating that a highperformance fiber-reinforced vulcanized rubber composite can be prepared under this process.…”

Hybrid enhancement of silica and aramid pulp on improving performance and reducing dynamic heat generation of natural rubber composites

“…The properties of rubber composites can be improved by filling only a small amount of aramid fiber. 21,22 However, aramid fiber is a rigid material and the surface of aramid fiber is chemically inert and poorly combined with the matrix material. [23][24][25] When subjected to alternating stress, aramid fiber will produce friction with rubber molecular chains and particles in the rubber matrix, causing a lot of heat.…”

“…Aramid fiber has the characteristics of high modulus, high specific strength and wear resistance. The properties of rubber composites can be improved by filling only a small amount of aramid fiber 21,22 . However, aramid fiber is a rigid material and the surface of aramid fiber is chemically inert and poorly combined with the matrix material 23–25 .…”