In situ generation of sulfur using silica as a carrier in the wet mixing of natural rubber latex

Abstract

Using sodium thiosulfate and hydrochloric acid as the raw materials and a silica aqueous dispersion as the carrier, sulfur is generated in situ by a chemical precipitation method, and an in situ sulfur‐silica/natural rubber (in situ S‐Silica/NR) composite is prepared. The in situ sulfur is characterized, and its effects on the natural rubber composites' cross‐linking density, vulcanization characteristics, mechanical properties, aging properties, dynamic mechanical properties, and Payne effect are studied. The experimental results show that the particle size of in situ sulfur is small, with a maximum of 5 μm, and the cross‐linking ability is stronger than commercial sulfur. Due to the strong surface adsorption force of silica, the interfacial bonding strength is enhanced, and the dispersion of the two components in the rubber matrix is improved. Compared with commercial sulfur‐silica/natural rubber (S‐Silica/NR) composites, the tensile strength is 20.3% higher, the elongation at break is 28.5% higher, and it better retains its aging properties and has a lower rolling resistance. This study provides a theoretical basis for the development of functional rubber vulcanizing agents and the preparation of high‐performance rubber composites.

Reinforcing mechanism and experimental study of environmentally friendly potassium oleate in silica/natural rubber system

“…The smaller the M L , the better the fluidity of the rubber composites. M H ‐ M L can be used to characterize the crosslinking density of vulcanizates 22 . Both the highest torque ( M H ) and the torque difference ( M H ‐ M L ) showed an increasing trend with the increase of PO dosage, indicating that PO can accelerate the cross‐linking reaction, and its dispersibility in the rubber matrix increases, thereby increasing the vulcanization efficiency 23 …”

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

“…After flocculation, sedimentation and drying, silica/rubber composite is obtained. [12][13][14] In the dry blending process, silica possesses some problems, such as difficulty mixing with rubber, poor dispersion, low content filling and dust pollution. Consuming a lot of water and rubber latex, time-consuming, low efficiency and unable to be produced continuously are the main reasons limiting its development.…”

“…Wet processing is that prepare silica slurry firstly, then use it to mix with rubber latex. After flocculation, sedimentation and drying, silica/rubber composite is obtained 12–14 . In the dry blending process, silica possesses some problems, such as difficulty mixing with rubber, poor dispersion, low content filling and dust pollution.…”

Improvement in strain‐induced crystallization and physicochemical property of natural rubber by protease treatment

“…12,13 Protein and phospholipids are the most important non-rubber components. 14 There are various kinds of amino acids in the protein of NR. Protein in NR can delay the aging of rubber and improve heat and oxygen aging resistance because some kinds of amino acids like glycine can play the role of antioxidants.…”

“…Natural rubber consists of more than 90% rubber hydrocarbons and less than 10% non‐rubber components 12,13 . Protein and phospholipids are the most important non‐rubber components 14 . There are various kinds of amino acids in the protein of NR.…”