Research progress of flame retardant polypropylene

2015-04-13

Polypropylene is used as a light, non-toxic, easy processing, good mechanical properties, resistance to chemical corrosion and othermaterials, has been widely used in many fields. But PP itself is very easy to burning, and the burning high calorific value, burning and dropletspread of flame, so that the polypropylene is severely restricted in flame retardant. With the expansion of PP applications, flame retardant PP has received more and more attention, but the halogen flame-retardant PPmany environmental problems. In recent years, with the study of halogenflame retardant polypropylene depth, based on the development of flame retardant polypropylene is becoming more and more clear.

Development and application of flame retardant polypropylene

Flame retardant polypropylene material design based on the currentresearch at home and abroad and its key, can be discussed from 3aspects of the above ideas spread.

Development of flame retardant polypropylene molecular level

Development of halogen flame retardant polypropylene is one of therepresentatives of this idea, it will produce hydrogen halide in thermal decomposition, while the hydrogen halide as a kind of active substance,and combustion of polymeric materials produced by the reaction of active free radical reaction. In order to reduce the concentration of freeradicals, and alleviate or even terminated polypropylene thermaldecomposition process of chain reaction, to prevent the purpose of combustion. Although this level of flame retardant effect is very good, butthe two pollution halogen has been greatly limits the application ofhalogen flame retardant, at home and abroad for the application ofhalogen flame retardant synergistic flame retardant gradually to thedirection of development, so as to reduce the increasing amount ofhalogen flame retardants. And look for alternative materials in an attempt to continue at the molecular level, the development of flame retardant polypropylene.

Development of flame retardant polypropylene applied physics level

The thermal decomposition process of polypropylene in the combustionwill produce a lot of heat, the heat will further accelerate polypropylenethermal decomposition rate, so it can be through the introduction ofadditives, heat absorption of polypropylene thermal decompositionprocess, thereby reducing the temperature of the composites reached the barrier, the purpose of combustion. Hydroxide flame retardant flame retardant polypropylene on the physical aspects of the design and development of a common flame retardant, classification from thecomposition and structure of magnesium hydroxide and aluminum hydroxide, mainly layered double hydroxides. This kind of flame retardant, good thermal stability, does not produce toxic gases in the combustion process, but also effectively reduces the release of smoke,flame retardant and smoke, to fill the role in flame retardantpolypropylene process, but also can produce synergistic flame retardantwith a variety of substances. But in order to get a better flame retardant effect, will need to increase the amount of sodium hydroxide, which leads to the processing performance of products, mechanical properties were destroyed.

Research prospect

Halogen free flame retardant modified by a decisive role to expand the scope of application of polypropylene, polypropylene, compared with the traditional halogen flame retardant, the flame retardant effect declined,but friendly to people's safety and the environment has become a strongsupport for the development and application of halogen free flame retardant. In recent years, a variety of non halogen flame retardant has been rapid development, but the lack of, in the application is vulnerable to the limit, as people gradually improve the material requirements,application and development of flame retardant polypropylene gradually added from the blind and simple ratio to material design, according to the requirements of the use of flame retardant polypropylene, design and development of the material, thus greatly enhance the flame retardant polypropylene material development and application prospect.