The development process of halogen-free flame retardants is a process that continues to evolve with the progress of science and technology and the continuous improvement of environmental protection needs. The following is a detailed review of the development history of halogen-free flame retardants:
Early developmental stage
The concept of flame retardants dates back to the ancient Greek period, when wood was impregnated in a solution of potassium aluminum sulfate to give it flame retardant properties. However, early flame retardants were mainly used in wood and fabrics, and the technology was relatively simple.
In the 1930s, flame retardants began to be applied in resin materials, marking an important milestone in flame retardant technology.
In the early 1950s, Hooker Chemical Company developed flame-retardant unsaturated polyester with reactive monomer chloromycetic acid, opening up a new way in the field of flame retardant. Subsequently, new reactive flame retardant monomers containing bromine and/or phosphorus continued to appear.
In the 1960s, brominated flame retardants became large-scale production chemicals and were used in many resin materials. During this period, the flame retardant industry has gradually developed and grown, and many flame retardant products have been produced, and the application field is also expanding rapidly.
Controversy and transition stage
Since 1986, the toxicity and environmental issues of PBDE flame retardants have been debated in the field of flame retardants. These controversies have prompted a search for greener and safer alternatives to flame retardants.
With the improvement of flame retardant requirements and the enhancement of environmental protection awareness, halogen-free, smoke suppression and toxicity reduction of flame retardants have become the research frontier. Halogen-free flame retardants are favored because of their low toxicity and small environmental impact.
Rapid development stage
Since the 1990s, halogen-free flame retardant technology has made significant progress. Inorganic metal compound flame retardants (such as aluminum hydroxide and magnesium hydroxide), expandable graphite, nitrogen flame retardants, silicon flame retardants and phosphorus flame retardants and other halogen-free flame retardants have been developed and applied.
These halogen-free flame retardants have their own characteristics in flame retarding mechanism, performance and application fields. For example, aluminum hydroxide and magnesium hydroxide inhibit combustion by endothermic decomposition and dehydration; The expandable graphite expands at high temperature to form a carbon layer to isolate oxygen. Nitrogen flame retardants release non-combustible gas when heated to take away heat; Silicon-based flame retardants form inorganic layers to prevent volatiles from escaping during combustion. Phosphorous flame retardants promote dehydration and carbonization of polymers by generating phosphoric acid, metaphosphate and other substances.
With the enhancement of global environmental awareness and the improvement of environmental regulations in various countries, the market demand for halogen-free flame retardants is growing rapidly. Halogen-free flame retardants are widely used in construction materials, cables, electrical equipment, automotive interior and other fields.
Current situation and future trend
At present, the halogen-free flame retardant industry is in rapid development. The global halogen-free flame retardant market continues to expand and is expected to maintain a high growth rate in the next few years.
The development trend of halogen-free flame retardants is to move towards a more environmentally friendly, efficient and multi-functional direction. In the future, with the advancement of technology and the expansion of application fields, the performance of halogen-free flame retardants will be further improved to meet the needs of more high-end application fields.
In summary, the development process of halogen-free flame retardants is a gradual evolution process from simple to complex, from low efficiency to high efficiency, from high toxicity to environmental protection. With the continuous progress of science and technology and the continuous improvement of environmental awareness, halogen-free flame retardants will play a more important role in the future.
