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Diatomaceous Earth as Rubber and Plastic Filler: Mechanisms of Wear Resistance and Anti-Aging Performance Enhancement

Sep 13, 2026

1. Introduction

Polymer materials including rubber and plastic are widely applied in industrial manufacturing, construction engineering, daily consumer goods and automotive industries due to their excellent ductility, moldability and low density. However, pure polymer substrates generally suffer from inherent defects such as poor surface hardness, weak wear resistance, susceptibility to ultraviolet aging, thermal oxidation degradation and dimensional instability under long-term service conditions. To compensate for these performance deficiencies, inorganic functional fillers have become essential auxiliary materials for polymer modification.

Traditional fillers such as calcium carbonate, talc powder and kaolin merely serve as inexpensive filling materials to reduce production costs, with limited enhancement on mechanical properties and aging resistance. Diatomaceous earth, as a biogenic porous functional mineral, possesses a unique three-dimensional skeleton structure, high structural rigidity, large specific surface area and superior chemical inertness. When applied as a high-performance filler for rubber and plastic products, it can effectively improve the microstructure of polymer composites, significantly enhance wear resistance, anti-ultraviolet and thermal aging properties, and optimize the overall mechanical stability of products. This paper systematically elaborates the modification mechanism and practical application advantages of diatomaceous earth in rubber and plastic reinforcement.

2. Microstructural Basis of Diatomite for Polymer Modification

The excellent modification performance of diatomaceous earth originates from its unique microscopic morphological characteristics. Different from the smooth and dense particle structure of traditional inorganic fillers, diatomaceous earth retains complete porous fossil skeleton particles. The hierarchical pore structure and rugged surface morphology enable it to form powerful physical interfacial bonding with rubber and plastic resin matrices.

During the mixing and vulcanization or molding process, the resin molecules can penetrate into the internal pore channels of diatomite particles, forming a stable mechanical interlocking structure. This tight composite interface greatly improves the bonding strength between the filler and the polymer matrix, avoids interfacial separation and microcrack propagation, and fundamentally enhances the structural compactness and mechanical durability of composite materials. In addition, the high-purity amorphous silica component of diatomaceous earth provides excellent weather resistance and structural stability for polymer products.

3. Mechanism of Diatomite Enhancing Wear Resistance of Rubber and Plastic Products

Wear resistance is a key indicator to evaluate the service life and operational stability of rubber and plastic products. Pure polymer materials are prone to surface abrasion, peeling and material loss under friction, extrusion and cyclic loading. Diatomaceous earth significantly improves the surface hardness and friction resistance of products through multiple physical reinforcement mechanisms.

3.1 Improving Matrix Compactness and Surface Hardness

Uniformly dispersed diatomite particles can fill the internal micro-pores and micro-defects of rubber and plastic matrices, reduce structural voids, and improve the overall compactness and uniformity of composite materials. The rigid siliceous skeleton of diatomite effectively increases the surface hardness of polymer products, reduces plastic deformation under friction, and inhibits the generation and expansion of surface microcracks, thereby lowering abrasive wear loss.

3.2 Dispersing External Friction Stress

The three-dimensional porous structure of diatomite forms a micro-buffering system inside the polymer matrix. When the product is subjected to external friction and extrusion stress, the diatomite skeleton can disperse and transfer local concentrated stress, avoid concentrated wear and local damage, and make the surface friction force uniformly distributed. This mechanism greatly improves the overall friction resistance and fatigue wear performance of rubber and plastic products.

3.3 Reducing Adhesive Wear and Scratch Damage

Traditional polymer materials are prone to adhesive wear and surface scratching during friction contact. Diatomite-modified products form a micro-rough wear-resistant surface with stable rigid particle distribution, which effectively reduces the contact area and adhesive force between the product surface and friction pairs, avoids adhesive peeling and scratch damage, and significantly improves the surface wear resistance of rubber and plastic products.

4. Mechanism of Diatomite Improving Anti-Aging Performance of Polymer Products

Rubber and plastic products are susceptible to aging degradation under long-term exposure to ultraviolet radiation, high temperature, oxygen and humid environments, resulting in surface discoloration, powdering, cracking, brittle fracture and reduced mechanical strength. Diatomaceous earth can effectively inhibit multiple aging processes and improve the long-term weather resistance of products.

4.1 Ultraviolet Shielding and Anti-Photoaging Effect

Diatomite’s unique porous micro-nano structure has excellent ultraviolet scattering and shielding performance. It can effectively absorb and reflect UVA and UVB ultraviolet rays in sunlight, prevent ultraviolet rays from penetrating into the polymer matrix, and inhibit the breakage of polymer molecular chains caused by ultraviolet radiation. This significantly delays photoaging, fading and powdering of outdoor plastic and rubber products.

4.2 Inhibiting Thermal Oxidative Aging Degradation

The stable chemical inertness of diatomaceous earth can isolate part of oxygen and heat, reduce the thermal oxidation reaction rate of polymer molecules under high-temperature conditions, and inhibit the aging and cross-linking degradation of rubber and plastic matrices. Meanwhile, the compact composite structure reduces the penetration of water vapor and oxygen, alleviates internal oxidative corrosion and aging fatigue, and improves the thermal stability of products.

4.3 Improving Dimensional Stability and Anti-Cracking Performance

Long-term aging of polymer products is often accompanied by thermal expansion and contraction deformation and structural cracking. Diatomite filler with low thermal conductivity and stable structural performance can effectively balance the internal stress of the matrix, reduce thermal deformation and shrinkage cracking, maintain the dimensional stability of products in complex temperature environments, and extend the overall service life.

5. Additional Comprehensive Performance Improvements

In addition to core wear resistance and anti-aging enhancement, diatomaceous earth can further optimize the comprehensive properties of rubber and plastic products. Its porous structure improves the heat insulation and sound insulation performance of polymer materials; its stable inorganic structure enhances chemical corrosion resistance and oil resistance; its good dispersion performance improves the processing fluidity and molding uniformity of composite materials. Compared with single traditional fillers, diatomite realizes multi-dimensional performance upgrading of polymer products.

6. Comparative Advantages Over Traditional Polymer Fillers

Conventional fillers such as calcium carbonate, talc and kaolin only provide simple physical filling and cost reduction effects, with limited improvement on wear resistance and aging resistance. Most traditional fillers have smooth and dense particle surfaces, weak interfacial bonding with polymer matrices, and are prone to interfacial peeling and internal defects after long-term use, which may even reduce the mechanical stability of products.

As a multifunctional modified filler, diatomaceous earth achieves strong interfacial bonding through physical interlocking structure, effectively improving the compactness and mechanical strength of composites. It integrates wear resistance enhancement, ultraviolet aging resistance, thermal oxidation stability and corrosion resistance optimization, which cannot be realized by traditional single-performance fillers. It is an ideal high-efficiency modified filler for high-end rubber and plastic products.

7. Conclusion

Diatomaceous earth, as a high-performance green inorganic filler, significantly enhances the wear resistance of rubber and plastic products by improving matrix compactness, dispersing friction stress and reducing surface adhesive wear. Meanwhile, its excellent ultraviolet shielding and thermal oxidation stabilization effects effectively inhibit the photoaging and thermal aging degradation of polymer matrices, greatly improving the long-term service stability and weather resistance of products.

With the continuous upgrading of high-performance polymer materials, diatomaceous earth will gradually replace traditional single-function fillers and become an important functional modified material in the rubber and plastic industry, providing reliable technical support for the development of high wear-resistant, anti-aging and long-life polymer products.

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