Online Training Courses

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1 Online Training Courses FR Systems Selection for E&E Applications Dr. Sitaram Rampalli Date: December 7, 2011 Could you recommend us a good FR for ABS to get Vertical Burning test VO? One of the good FR for ABS is polymeric brominated epoxy (BEO). With BEO, a rating of V-0 (1.6 mm) is achieved at a bromine level of 11%. BEO also helps in improving the thermomechanical properties of the formulation with no surface blooming. According 34 slide - How many TPP we need to add to PC/ABS and what ratio PC/ABS do you recommend? In the case of PC/ABS, TPP is one of the best suited flame retardants. The exact level of TPP is difficult for me to recommend without knowing a lot more details on the exact composition of the base polymer and other additives present in the system. The usual range of loading for TPP is anywhere from 10-16%. The required loading also depends on the PC/ABS ratio. In many commercial PC/ABS blends, ABS ratio is approximately 25%. It is very important to conduct some experiments to determine the exact loading required to achieve the required flame and other essential properties in your material. PTFE powder is also added to these formulations to improve the anti-dripping properties. Could you give us an examples of using nanofillers in the industrial compounds, is it preferred to combine nano with traditional FR or to use along? Refer to slide #13 about nano-fillers. Usually it is preferred to combine nano-fillers with traditional fillers to achieve the required flame retardant properties. What synergistic FR systems could you recommend for PP, PE, ABS/PC? Halogen free Zinc borate is one of the most widely used synergist for halogen free PP and PE systems. I am not very familiar with a synergist that can be used along with PC/ABS halogen free system. There are some studies on the use of nitrogen compounds along with phosphorous containing flame retardants but I am not sure if it would work in PC/ABS.

2 What is the maximum injection temperature to use with metal hydroxide compound (MDH)? The decomposition temperature of MDH starts at around 350 C. In my opinion, the maximum injection temperature that can be used should be far below 350 C to prevent any decomposition of MDH. A temperature in the range of C should work for injection molding. However, it is recommended to run the thermogravimetric (TGA) scan on the sample to determine the exact start of the decomposition temperature of the MDH. Slide 8, what happens when particle size alters? Since ATH or MDH have to be compounded with the polymer a very high loading (60-65%) is required to reach the optimum level of flame retardancy. Particle size and distribution plays an important role in optimizing both mechanical and flame properties of the polymer. The main function of the uniform particle size is that it helps in uniform packing of the filler more effectively at these higher loadings and hence giving lower viscosity. This ultimately helps in better flow properties under the conditions of extrusion or injection molding operations. Uniform particle size also helps in fire performance in a more predictable way. What is your opinion regarding halogenated FR future taking into consideration NGO pressure (greenpeace) and European regulation evolution (Reach/Rohs)? In my opinion, it will be still a long process before all the halogenated FRs are completely banned. Certain brominated compounds are still offering excellent flame related performance in some of the E&E products at a reasonably low cost. Even though, I am in support of the non-halogenated FRs for use in all the consumer products, a total shift away from halogenated FRs might hamper the progress of the industrial production. Is it possible to have a V0 level with nanocomposite FR on Polyamide? if so, what will be the loading? I don t believe that it is possible to achieve V-0 rating with 100% nanocomposite. Besides, nanocomposites are somewhat expensive to use by themselves. In most of the instances, they are used in conjunction with another primary flame retardant additive. At what temperature does talc release inert gases? The decomposition of Talc starts around 500 C. Talc is essentially a hydrated magnesium silicate, Mg 3 Si 4 O 10 (OH) 2. In addition to the main composition, talc also contains other mineral impurities such as, enstatite, dolomites, calcites, magnesites and quartz. The main gaseous product that comes out of talc is water vapor with minor amounts of carbon dioxde. What is the definition of "condensed phase"? Liquids and solids are often referred to as condensed phases because the particles are very close together.

3 Does a transparent FR exist for PC? Or have PC itself FR properties? I doubt if there are any transparent FR systems out there in the market at this moment. As far as PC goes PC has some inherent flame retardant properties. The limiting oxygen index is around 25. However, this is not considered as a very high value and hence can not be used for high end flame retardancy applications. It is possible to make PC more flame retardant without sacrificing too much of transparency. Bromine containing flame retardants such as tetrabromobisphenol A oligocarbonate is one example. Usually around 8% loading is necessary to reach V-0 rating at 1.6 mm thickness. Addition of small amounts of PTFE powder will provide anti-drip properties to PC. Addition of PTFE will help in reducing the flame retardant in the formulation. The resulting FR PC will be translucent instead of transparent. What is the greatest market or technical needs with regard to the use of metal hydroxides in polyolefins? A vast majority of market for metal hydroxide is in the area of polyolefins, elastomers and other thermoset plastics. Metal hydroxides are used quite extensively in wire and cable industry. Besides providing zero halogen benefits, these flame retardants are relatively less expensive. The technical needs are: right particle size, proper surface coating to promote compatibility with the polymers, and good flame retardancy. Are there any quantitative criteria that would exclude some FR from some E&E application? What about conductivity measurements on FR additive itself? One of the important quantitative criteria is that the added FR should not adversely affect the mechanical properties of the system. Further, the FR additive should be compatible with the resin system that is used. Yes it is possible to do conductivity measurements on the FR additive itself. But it is more meaningful to measure the conductivity on the compounded formulation to determine if that is suitable for a given application or not. Is it possible to regrind MDH polyamide? given the thermal sensitivity to magnesium hydroxide compounds, can we reuse the injection scraps in injection molding (eg regrinding) Low percentage of regrind consisting of MDH/PA can be added to the virgin batch, provided there is no excess heat history on the regrind. Good temperature control is very important and care must be taken not to exceed the temperature limits suggested for MDH. Otherwise, there is a danger of losing the water of hydration from MDH thereby rendering it useless as a flame retardant additive. I think it is important to run some analytical tests such as TGA on the regrind to make sure that there is no composition change in the regrind compared to the starting material. I would also recommend cryogenic regrind process to minimize the degradation of the scrap.

4 Can you elaborate on the method for measuring the dielectric properties? It is not possible here to discuss all details of these tests. I can direct you to the following sources for finding the details on these tests: Dielectric Constant and Dissipation Factor: ASTM D150, IEC 60250; Dielectric Strength: ASTM D149, IEC 60243; Comparative Tracking Index (CTI): ASTM D3638, IEC 112. To achieve the flame retardancy (V0) using nonaclays with polyolifins, do they need to be exfoliated? Exfoliation leads to homogeneous dispersion of silicate layers within the polymer matrix as opposed to intercalation. Exfoliation thus increases polymer-clay interactions, making the entire surface of the layers available for the polymer. This type of system will exhibit better mechanical and physical properties. In practice, when you compound a nano-composite with a polyolefin like EVA, not everything will show up as exfoliated. It could be a blend of both exfoliated and intercalated structures. As far as flame retardant performance, I don t believe that there will be any difference as long as you have some form of nano-composite in the formulation. Just a comment to slide 36: the cost of ammonium polyphosphate of $0.45/lb seems to be very low? Is this correct? The price given $0.45/lb is according to some of the Chinese suppliers. I have no specific pricing information on the international market. As you know the price changes according to the volume. What a FR formulation for PC/ABS compound with low smoke and toxicity level could you recommend Phosphate flame retardants are best suited for PC/ABS. These include: Triaryl phosphates such as triphenyl phosphate (TPP), resorcinol bis-(diphenyl phosphate) etc. In practical product development, the level (amount) of arylphosphate necessary to reach V0 rating depends on the PC/ABS ratio. Typically, higher the PC/ABS ratio, the lower the phosphorous concentration required for V-0 rating. Thickness of the part is also equally important to optimize the FR loading. You may have to conduct some experiments to optimize the FR loading into the PC/ABS. Sometimes Talc or Aluminum oxides are added as synergists. According to your presentation hydroxides are broadly used for E&E applications, but can we use them if we need a high value of dielectric breakdown strength? It is generally true that bound water in most of the metal hydroxides will decrease the breakdown strength. However, it depends on how much strength is needed in a given formulation. Typical value of breakdown strength for ATH is: 11.8 kv/mm Since ATH is used in combination with a polymer and it is well dispersed, the actual value might be different.

5 What is the recommended particle size of talc to use as a flame retardant? I cannot recommend a particular grade or particle size Talc for your specific application because I have no idea what product you are interested in. As far as I know the average particle size is around 2.8 microns. You need to contact the manufacturers of Talc to get more specific information. Slide 13 silicades, what kind were you talking about? Are you not thinking about nano clays? Focusing on polycarbonates can you suggest any good FR systems so to keep the good transparency. We need to keep the same hays performance. Asia names as well. See the above answer about PC. Excuse me but can you be a bit more specific about Asia? Are you looking for agencies dealing with Asian standards or Asian regulatory agencies? You can contact me on my and I will look up the information for you. We are always happy to hear about what you think, what are your needs for training, information so please let us know by writing at the following address: e-training@ specialchem.com