This page contains a Flash digital edition of a book.
ADDITIVES | FLAME RETARDANTS


“The APP product line will reduce total dosage, improve price and properties of the compounds,” he says. A line of products targeting mineral additives such as aluminium hydroxide/magnesium hydroxide (ATH/MDH) is also going to be launched next year, following promising results achieved with customers. The main claimed benefits include improved mechanical properties, lower density and better processability, as well as improved burning properties of the material. Paul says that Paxymer also aims to start expand-


ing its product offering to include synergists for engineering resins. This work will begin in 2018 and the aim is to have a range available in the medium term. In the meantime, the company’s line of highly filled masterbatch products developed


for converters is said to be growing rapidly in the pipe/conduit market both for PP and PE products. Mechanical properties in combination with excel- lent smoke values and excellent processability are said to be driving the growth.


Synergistic solutions Dow Corning describes its Dow Corning 43-821 additive as the first in a new family of unique synergists for flame-retardant PA compounds. The phosphorus-free additive is said to deliver “excel- lent” FR properties, including strong char forma- tion, anti-dripping, and reduced heat generation. Speaking at the Performance Polyamides 2017


conference organised by Compounding World publisher AMI in Cologne in June, Dow Corning


Fighting fire…but with wood?


It may sound a crazy idea, but researchers at the Fraunhofer LBF research institute in Germany are developing flame retardants based on wood – or more precisely on the wood waste product lignin. It seems this is available in abundant quantities as a by-product from paper produc- tion with up to 98% of it currently disposed of by burning for energy recovery. Following on from its involvement in the EU-sponsored Phoenix research into FR nanostructured materials, Fraunhofer LBF believes it has developed a more sustainable use for this lignin as a flame retardant additive by binding it with phosphorus. Even untreated, lignin is known to


be able to reduce the flammability of plastics. However, Fraunhofer LBF says the flame inhibition effect is too low in most cases. In addition, due to its poor compatibility with most plastics, the addition of lignin also reduces mechanical properties. Combining lignin and phosphorus compounds together increases the flame retardant effect, says the institute, but the result is still limited due to the spatial separation in the final compound. “We were able to solve this problem by chemically binding the phosphorus to the lignin,” says Dr Roland Klein, group leader of interface design at Fraunhofer LBF. The institute has already provided project partners with large quantities


of material for processing with different plastics. Fire tests carried out at the University of Lille on a mass loss calorimeter showed a lower heat development in plastics that con- tained the Fraunhofer LBF “phospho- rylated lignin” compared to those containing pure lignin. Fraunhofer has also addressed distribution problems of the modified lignin in polypropylene. “With a further chemical modification of the lignin [to increase hydrophobicity], we were able to improve its compatibility with polypropylene,” says Klein. This showed up in a finer morphology and improved mechanical properties of the compound. � www.lbf.fraunhofer.de/en


SOURCE: FRAUNHOFER LBF


A researcher at Fraunhofer LBF engaged in a project to use phosphorous modified lignin as a flame retardant


38 COMPOUNDING WORLD | December 2017


Heat release rate data for an ABS polymer with no fire retardant, with lignin and with Fraunhofer’s phosphorylated lignin


www.compoundingworld.com


PHOTO: FRAUNHOFER LBF


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78