Physical modification Methods and advances of PP
2013.09.06 08:43Although PP has many advantages,in the low-temperature impact resistance,easy to aging,molding shrinkage rate,easy burning, dyeing,have a fundamental weakness,so as a structural material and engineering plastic materials Limited,this must be the modification of PP for various kinds of,to broaden its scope of application,the modified PP from general plastics into the ranks of Engineering plastics.?xml:namespace>
Modification of PP includes two categories:one is a chemical modification,the other is a physical modification.
Physical Modification
The physical modification is the addition of other inorganic materials,organic materials,and other varieties of plastic,rubber varieties,thermoplastic elastomer in PP matrix,or some additives have special function,the PP composite material through mixing,kneading and obtained excellent performance.The physical modification can be divided into:filling modification,modification,blending modification,functional modification.
The physical modification process is simple,do not need complex or special equipment,use of plastic molding factory original equipment.But in the modified products require special properties,you need to add special equipment,such as a magnetic plastic extruder,need to add enhanced magnetic field equipment etc.
1.filling modification
Organic inorganic filler,filler amount in PP resin,to improve product performance,and can reduce the material cost.PP filled with inorganic fillers are commonly used:mica powder,calcium carbonate,talc,wollastonite,carbon black,gypsum,red mud,lithopone,barium sulfate,organic fillers are commonly used:wood flour,rice husk powder,peanut shell powder.
2.reinforced modified
Reinforced modified PP can replace the engineering plastics,the reinforcing material is glass fiber,asbestos fibers,crystal fibers and beryllium,boron,silicon carbide,and filler modification of mica.Talcum powder processing HERSHEY'S,also can be used as reinforced materials used.
Blending modification is the use of other plastic,rubber,or thermoplastic elastomer blends with PP,fill in the crystal ball larger PP,in order to improve the toughness and low temperature brittleness of PP.
Addition of rubber or elastomer is the main way of the modified PP,as in PP can add the world:butadiene rubber,ethylene propylene rubber,styrene butadiene block copolymer (SBS) ethylene propylene diene three copolymer (EPDM),natural rubber,butadiene rubber etc.
3.other modified
Flame retardant:PP as the combustible material,the decomposition temperature of 320-400 ℃,the ignition temperature of 350 ℃,horizontal burning rate of 37 mm/min,oxygen index 18.5.
Antistatic modification:adding carbon black as conductive filler in PP,can make the surface resistance of products is reduced to below 10 ohms.
There are other used or plating surface treatment:two processing of modification,in the PP to add antioxidant,anti UV agent to improve the heat,light aging properties of nuclear modifier.
By Emily