What Are the Best Flame Retardants for Polypropylene (PP)?
Introduction
Polypropylene (PP), one of the five major general-purpose plastics, is widely used across industries. However, its flammability limits its applications. This article explores PP’s combustion process, flame retardants, and their applications in packaging.
Combustion Process and Mechanisms
- Combustion Process
- Thermal Decomposition: As temperature rises, weak bonds break, leading to the formation of flammable gases.
- Ignition: Flammable gases mix with oxygen, reaching ignition conditions.
- Sustained Combustion: Burning releases heat, accelerating decomposition and sustaining the fire.
2.Flame Retardant Mechanisms
- Chain Reaction Termination: Interrupts free radical reactions.
- Surface Isolation: Forms a protective layer on the surface.
- Heat Exchange Interruption: Absorbs heat, preventing sustained combustion.
Flame Retardants for PP
- Metal Hydroxide Flame Retardants
- Activated Carbon Modified Magnesium Hydroxide: Enhances compatibility and flame retardancy. Optimal at 25wt%, LOI reaches 28.9%.
- POE and Nano-CaCO3: Improve mechanical strength while maintaining flame retardancy.
2.Boron-Based Flame Retardants
- BN@MGO: Enhanced affinity and uniform distribution, suitable for electronic devices.
- APP/MCA-K-ZB: Achieves UL-94 V-0 rating with LOI of 32.7%.
3.Silicon-Based Flame Retardants
- HNTs-Si: Forms dense char layers, improving thermal stability and flexibility.
- Nano-Sb2O3 and OMMT: Enhance crystallinity and tensile strength.
4.Phosphorus-Based Flame Retardants
- Sorbitol and Ammonium Polyphosphate: Form protective char layers, enhancing flame retardancy.
- SPDEB and Ammonium Polyphosphate: Capture free radicals, reducing combustible gases.
5.Nitrogen-Based Flame Retardants
- MPP and Ammonium Phosphate: Release non-flammable gases, diluting flammable gases.
- APP@MEL-TA: Improves dispersion and forms a gas barrier.
6.Intumescent Flame Retardants
- NiCo2O4: Enhances carbonization and forms stable char layers.
- OS-MCAPP and PEIC: Promote high-quality char formation, achieving UL-94 V-0 rating.
Applications in Packaging
- Battery Enclosures
- PP/Ammonium Polyphosphate/Triazine: Low density, high impact resistance, and excellent flame retardancy.
2.Part Component Packaging
- PP/MHSH/Al2O3/N-P: High thermal stability, enhanced mechanical properties.
3.Food Containers
- Recycled PP with IFR: High potential for recycling and reuse.
Current Challenges
- High Additive Levels: Affect mechanical properties.
- Halogen-Containing Retardants: Environmental concerns.
- Cost: Expensive retardants increase production costs.
About Baozhuan New Material
Chongqing Baozhuan New Material Technology Co.,Ltd has a team of senior R & D, marketing and sale in the polymer industry, focusing on the innovative R & D, production and sales of high-end plastic additives.The main products are silicone masterbatch, silicone powder, flame retardant, flame retardant synergist, light stabilizer, rheological agent, laser marking additives, compatilizing dispersant, lubricating dispersant, adsorbent and so on. Adhering to the business philosophy of integrity, innovation, pragmatism and efficiency, the company is committed to becoming an expert in the overall solution of high-quality polymer additives.
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Chongqing Baozhuan New Material Technology Co.,Ltd has a team of senior R & D, marketing and sale in the polymer industry, focusing on the innovative R & D, production and sales of high-end additives.
The main products are silicone masterbatch, silicone powder, flame retardant, flame retardant synergist, light stabilizer, rheological agent, laser marking additives, compatilizing dispersant, lubricating dispersant, adsorbent,etc.Official website Address:https://www.additivebz.com/
