Wuhan Handern Halogen Free Flame Retardant Polypropylene
DATE：2020/6/11 8:32:24 / READ： / SOURCE：This station
Wuhan Handern Halogen Free Flame Retardant Polypropylene
The synergistic system of halogen-based flame retardants and antimony compounds forms toxic compounds, corrosive gases and soot during combustion or thermal cracking (even high-temperature processing). Out of environmental protection requirements, the call for non-flammable flame retardants is increasing day by day, and halogen-free flame retardant PP is also emerging. www.handern.com Paper laminating machine
Among the flame retardants that have been used and can be used for halogen-free flame retardant PP, the most promising and engineering application prospect is the intumescent flame retardant (IFR). When the PP containing FR burns and thermally cracks, it passes through the condensed phase The carbon formation mechanism that occurs in the process plays a flame retardant role, and the oxygen index of some polymers has a good correlation with the amount of carbon formed during combustion.
In recent years, a series of phosphorus-nitrogen mixed IFRs suitable for PP have been developed. When the components in the mixed FR are used alone, the flame retardancy of PP is not good, but when they are used together, the flame retardancy of PP is significantly improved due to the increase in carbon formation rate. There is also an IFR composed of expanded graphite and other synergists, which is also receiving attention. www.handern.com Paper laminating machine In addition, in recent years, some monomers IFR which have three sources (acid source, carbon source and foaming source) in the same molecule have been synthesized, and their application in P is being studied. Flame retardant P with DFR, when the dosage is 20% to 30%, O can reach more than 30, can pass the UL94V0 level, no dripping, not easy to come out, the smoke and toxic gases generated during combustion or thermal cracking are less than antimony antimony The flame retardant system is greatly reduced. However, the application of FR is also subject to certain restrictions, mainly because their thermal stability cannot fully meet the needs, the hygroscopicity is large, and the addition amount is also high.
Another type of halogen-free flame retardants used for flame retardant PP are aluminum hydroxide and magnesium hydroxide, which have been applied in the flame retardant PP industry. These two inorganic flame retardants are non-toxic, non-volatile, and do not cause corrosion Gas, and smoke suppression, but the amount of addition is large, which has a very adverse effect on the physical and mechanical properties of P and melt flow properties. In addition, the decomposition temperature of aluminum hydroxide is still low, and it is only suitable for flame retardant PP products that can be processed at lower temperatures. Using some special technologies (such as surface treatment) can improve the heat resistance of aluminum hydroxide and its dispersibility in PP, and can successfully produce PP that is flame retardant with aluminum hydroxide.
When flame retardant PP is flame retarded with a halogen-free silicon-based flame retardant, the flame retardant can be partially incorporated into the P structure through a cross-linking mechanism similar to the interpenetrating polymer network (IPN) part, which is not easy to migrate and can obtain durable flame retardancy. Sex. www.handern.com Paper laminating machine
Microencapsulated gelatinized red phosphorus and its masterbatch with PP as a truncated body can also be used as halogen-free flame retardants for P. It is often used in conjunction with chlorine oxide and magnesium hydroxide. But red phosphorus has better flame retardant effect on oxygen-containing polymers (such as PC, PET, etc.), and it has a worse flame retardant effect on PP. www.handern.com Paper laminating machine
Ammonium polyphosphate (AP) is the main component of mixed IFR. It is often used together with other synergists to form IFR. Most of these synergists are gas sources and sources, such as pentaerythritol (PETOI), three-step chloramine (MA), Trisalicylic acid (IHEIC), etc. When flame retardant P is used by IEFR, firstly mix PP and IFR on the mixing machine (twin-screw extruder, two-way open mixer, refiner, etc.) in the molten state, the temperature can be 160～200℃0, the speed of the mixer It is 40r/min, and the mixing time is 4～12min. Subsequently, the mixed sample was registered and shaped at 170-230°C. www.handern.com Paper laminating machine
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