Thread Content
Introduction to ABS resin: ABS is an acrylonitrile-butadiene-styrene terpolymer that not only possesses excellent mechanical properties with a balanced combination of rigidity, hardness, and toughness, but also excels in terms of coloring ability, surface gloss, processability, dimensional stability, low-temperature resistance, and chemical resistance. ABS has poor flame-retardant properties; its Limiting Oxygen Index (LOI) is only around 19.0%. It also lacks thermal stability and is prone to burning, which makes it difficult to carry out rescue operations in the event of a fire. ABS/polycarbonate (PC) alloys possess good heat resistance, impact resistance, and processability, which greatly expands the applications of ABS resin. However, their LOI is only around 24.0%, and their flame-retardant properties are poor, posing safety hazards. Therefore, improving the flame-retardant properties of ABS and ABS/PC alloys, expanding their range of applications, and enabling them to meet fire safety standards for use in fields such as automobiles, electrical appliances, and electronics where plastics can replace steel, holds great market potential. Flame retardant classifications: ★ Halogen-based flame retardants ★ Phosphorus-based flame retardants ★ Nitrogen-based flame retardants ★ Silicon-based flame retardants ★ Metal hydroxide flame retardants ★ Intumescent flame retardants. Flame retardant mechanisms: The combustion of most substances requires four conditions: a combustible material, an oxidizing agent, a heat source, and free radicals for chain reactions. By suppressing one or more of these conditions during the combustion process, it is possible to achieve flame retardancy. Therefore, the flame retardant mechanisms can be categorized as follows: ★ Heat absorption and cooling ★ Gas-phase dilution ★ Insulation layer protection ★ Termination of free radical chain reactions. Applications of dibutyl tin maleate (TMG 234): ★ Used as a heat stabilizer for ABS/PVC alloys; the recommended addition level is 0.03–1%. ★ Used as a heat stabilizer for flame-retardant ABS, especially when halogen-based flame retardants such as hexabromocyclododecane are used; the recommended addition level is 0.1–1%. ★ Used in ABS/PTFE blends with flame-retardant properties. ★ Used as a coupling agent for glass fiber-reinforced thermoplastic ABS to improve its impact strength. ★ Used as a dispersant for TiO2 in ABS. Applications: Flame-retardant ABS and ABS/PVC alloys. Properties: Heat stability, light stability, flame retardancy. Form: Solid powder; easy to add, does not precipitate