silicone adjuvant

Domestic Silicone Tougheners Outperform International Leaders in Polycarbonate (PC) Applications

For a long time, the niche market of silicone-acrylate core-shell impact modifiers has long been technologically dominated by a small number of foreign enterprises. However, continuous investment in domestic new material R&D is breaking this monopoly. Domestic silicone tougheners not only fully match imported top-tier products in silicone content but also surpass overseas counterparts in key indicators including hydrolysis resistance, hydrothermal aging resistance, high-temperature processing stability, and low-temperature impact toughness.

Domestic and foreign manufacturers adopt identical technical routes chemically: silicone copolymerized acrylate core-shell structure. The inner core is hybrid silicone-acrylate rubber phase, and the outer shell consists of polymethyl methacrylate (PMMA, MMA resin). Silicone content is controlled at 20±1 wt% to guarantee favorable compatibility with PC matrix resin.

Nevertheless, domestic manufacturers have pioneered distinct pathways in molecular design and process control: Overseas products prioritize balanced mechanical performance at ambient and low temperatures. Optimized shell grafting ratio enables efficient stress transfer at room temperature, delivering outstanding impact performance under standard conditions; these are typical general-purpose balanced modifiers. By contrast, domestic grades are customized for PC applications exposed to hydrothermal aging, high-temperature processing and low-temperature service environments. Via regulating silicone crosslink density and interfacial bonding force, they retain baseline room-temperature impact performance while greatly improving hydrolytic stability, thermoforming stability and low-temperature toughness in PC composites.

Hydrothermal Durability: Generational Performance Gap

Test data shows both general-purpose modifiers deliver nearly equivalent impact strength under dry ambient conditions. But once subjected to high-temperature high-humidity aging, the durability gap of their modified PC materials expands exponentially. After 504 hours of 85°C/85%RH damp-heat aging (Double 85 aging), PC filled with foreign tougheners becomes fully brittle and unusable, while domestic-modified PC retains approximately 70% of its original impact strength. This proves domestic products achieve service lifespans several times longer than imported general-purpose grades for harsh scenarios such as outdoor exposure, humid coastal environments and high-moisture service conditions.

High-Temperature Thermoforming Stability: Hidden Advantage for Processing

Simulated production testing with 18 minutes of thermal residence at 300°C yields an Izod notched impact strength of 722 J/m for domestic material, corresponding to a performance retention rate of 92.4%. In comparison, foreign material drops to 703 J/m with only 89.7% retention.
Furthermore, domestic tougheners exhibit remarkable low-temperature impact resistance at -30°C, perfectly matching demanding applications requiring extreme environmental tolerance, including new energy vehicle PC components, outdoor electronic enclosures and photovoltaic junction boxes.