Silica nanoparticles reinforced natural rubber latex composites: The effects of silica dimension and polydispersity on performance

Abstract

The nano‐size autonomous monodisperse silica (AS) particles were prepared by hydrolysis and condensation of tetraethoxysilane using l‐lysine as catalyst. The silica/natural rubber (NR) masterbatches were then produced via latex compounding, in which NR latex was mixed with the above AS dispersion. The commercial precipitated silica (PS) was introduced as a control. The effects of both AS and PS particles on the interfacial and mechanical properties of composites were systematically examined. It was found that the AS formed bead‐like morphology wherein the clear particle edges can be distinguished in rubber matrix. Compared with PS/NR, the AS/NR composites were proved to possess more bound rubber and weaker filler–filler interaction resulting in higher tensile strength, abrasive resistance, and resilience. Meanwhile, the efficiency of premodified AS and PS surfaces using bis‐(3‐triethoxysilylpropyl) tetrasulfide on reinforcing the properties of silica/NR composites was studied. The results presented that the overall properties of modified silica/NR vulcanizates were improved significantly. In special, the values of heating building‐up and compression set showed an evident decline which was of great significance for tire tread or other rubber products. For the dynamic properties, the magic angle spinning/NR composites had lower rolling resistance. In short, AS may be applied as an ideal substitution of PS in rubber. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47449.

Covalently functionalized uniform amino-silica nanoparticles. Synthesis and validation of amine group accessibility and stability

“…5,6 Silica nanoparticles with surface modication are of great interest as potential supports for proteins, 7 therapeutic drugs, [8][9][10][11] uorophores, 12,13 active groups for separation/catalysis, [14][15][16][17][18][19] and polymers. 13,[20][21][22] Surface modication also allows redispersion and colloidal stability in a variety of media, [23][24][25] which has been difficult specically for silica due to the high density of surface silanol groups causing irreversible aggregation. 26 It has been reported that irreversible aggregation becomes more severe as particle sizes decrease, 24,27 but in the case of mesoporous particles complete redispersion can be obtained aer drying with the aid of sonication, with the smallest hydrodynamic diameter obtained approximately 40 nm.…”

Surface Modified Nanocellulose and Its Reinforcement in Natural Rubber Matrix Nanocomposites: A Review

“… [ 20 ] Silica -precipitated silica (PS), autonomous monodisperse silica (AS) Silane treatment Silica dimension and polydispersity Tensile Strength and Abrasive Resistance PS reinforced rubber showed better tensile strength and abrasive resistance than AS reinforced rubber. [ 21 ] Silica from rice husk Alkali treatment Silica loading of 60 phr Curing Characteristic The result shows that the curing time of the rubber composites decrease with increasing silica loading. Tensile Strength The tensile strength was determined at the break point of the specimen.…”

Preparation and performance of oleylamine modified silica‐reinforced natural rubber composites

“…12,13 Consequently, unmodified silica can easily aggregate into larger-sized particles in rubber matrix through the interaction between silanols, and cause poor reinforcement effect. 14,15 The surface modification of silica is a very effective route to prevent the aggregation of silica particles, and silane-coupling agents are widely used to modify surface of inorganic particles. The silanols formed by hydrolysis of silane-coupling agent can dehydrate and condense with the silanols on the surface of silica to form silyl ether, which is chemically bonded to the surface of silica to prevent the formation of silica aggregates.…”

“…However, with a large number of polar silanols on the surface, silica exhibits strong hydrophilicity and poor compatibility with most hydrophobic rubber matrices 12,13 . Consequently, unmodified silica can easily aggregate into larger‐sized particles in rubber matrix through the interaction between silanols, and cause poor reinforcement effect 14,15 …”