At present, the main treatment methods of waste rubber products are processed into recycled rubber and ground into vulcanized rubber powder, mainly including tire rubber powder, EPDM rubber powder and nitrile rubber powder, which are mostly filled in PP, PE, PVC, EVA, ABS. The materials are modified in the composite materials; the nitrile rubber powder has the best modification effect, and the toughness of the composite material can be significantly increased in the ABS composite material; however, in the actual production, the nitrile rubber powder is used for the ABS composite material modification. The amount is not as much as possible, and it is necessary to control the dosage reasonably.
1. Nitrile rubber powder improves the toughness of ABS composites
Nitrile rubber powder is a renewable resource of waste nitrile rubber products such as nitrile gloves. It is heat-resistant, wear-resistant, solvent-resistant, and highly flexible. It has good compatibility with various polymers and is a variety of rubber and plastic products. Commonly used modified rubber powder; research shows that the addition of waste nitrile rubber powder in ABS composite can improve the impact strength of composite materials. When the mass fraction of nitrile rubber powder is about 60%, the impact strength is increased by more than 30%. It has obvious toughening effect; it can be seen that the addition of nitrile rubber powder can significantly improve the toughness of ABS composite.
2. Advantages of nitrile rubber powder in ABS composites
At present, the common rubber powders on the market include tire rubber powder, EPDM rubber powder and nitrile rubber powder. Different rubber powders have different effects in ABS composite materials. When adding tire rubber powder, EPDM rubber powder and nitrile rubber powder in ABS composite materials, the impact strength of ABS composite materials with tire rubber powder and EPDM rubber powder will increase with the increase of mass fraction. The increase is slightly increased, and it decreases rapidly after increasing to a certain value. When the mass fraction is 20%, the impact strength of the composite material is basically unchanged, and the toughening effect is not obvious. Relatively speaking, nitrile rubber powder can significantly increase the toughness of materials in ABS composites.
When the mass fraction of rubber powder in ABS composite is higher than 20%, the composite material begins to exhibit the characteristics of rubber, and the elongation at break will increase rapidly; and the ABS composite material with tire rubber powder and EPDM rubber powder is added. The ABS composite modified with nitrile rubber powder with the same mass fraction has the largest elongation at break.
3, nitrile rubber powder modified ABS composite material to control the dosage
Under normal circumstances, the nitrile rubber powder added to the ABS material will be dispersed in the ABS, destroying the continuity of the ABS material, and the dispersion point of the rubber powder is easily broken when subjected to external force stretching, thereby causing the tensile strength of the ABS composite material to decrease. . A small amount of nitrile rubber powder uniformly dispersed in the ABS composite material will buffer part of the external force in the ABS material, and the bending strength of the composite material will increase slightly; however, when the amount of the nitrile rubber powder is too large, the interface between the rubber powder and the ABS material cannot be adhered. The dispersibility of the nitrile rubber powder in ABS is reduced, resulting in a significant decrease in the bending strength of the ABS composite under external force.
In the actual production, the use of nitrile rubber powder in the ABS material can significantly improve the impact strength and elongation at break of the composite, and the toughening effect is remarkable; however, the excessive use of the nitrile rubber powder will seriously affect the tensile strength of the composite. And bending strength, therefore, it is necessary to properly control the amount of nitrile rubber powder in the ABS composite.