EuroWire September 2021

Technical Article

[4] J.C. Haley, N. Palyam, C. Schneider, “New Ethylene Vinyl Acetate Copolymers for Wire and Cable Compounds,” IWCS, Orlando, 2017. [5] J.C. Haley, N. Palyam, C. Ringham, “New Ethylene Vinyl Acetate Copolymers for Wire and Cable Compounds,” IWCS, Providence, 2018. [6] M.L. Rosa, A. Tankink, M. Hoch, ”Highly Flexible Halogen Free and Flame Retardant Thermoplastic Cable Compounds Modified with EVM Polymers” IWCS, 2008.

Courtesy of IWCS Cable & Connectivity Symposium, Charlotte, North Carolina, USA

▲ Figure 2 : Per cent tensile elongation on compounded samples containing 60 per cent MDH

Figure 2 plots the per cent elongation at break results for each sample. These results are also listed in Table 2 . Experimental samples that do not contain any MA-g PE exhibit a substantial increase in elongation. Subsequent experimental samples show that increasing the amount of MA-g PE in a formulation has a tendency to decrease the per cent elongation of the sample. This decrease in per cent elongation with increasing MA-g PE concentration is more pronounced in formulations containing the new experimental EVA, until the two lines converge when the formulation contains 3 per cent MA-g PE. At 3 per cent MA-g PE, there is no longer a notable improvement in elongation fromuse of the new experimental EVA compared to standard EVA. The loss in improvement in elongation for compounds containing 3 per cent MA-g PE is seen both in the compounds containing 9 per cent LLDPE and compounds containing no LLDPE. Therefore, we conclude that this reduction in elongation improvement is not simply dilution of the experimental EVA within the formulation. Instead, we hypothesise that the experimental EVA is performing a function similar to theMA-g PE, such that the two are in competition within the formulation. As a result, increasing the MA-g PE mutes the improvement of our experimental EVA. That said, this shows potential for our new experimental EVA to reduce the need for use of MA-g PE. 5 Conclusions We have developed a new EVA copolymer designed for use in LSZH flame-retardant compounds. The material modification that we have made produces a substantial increase in the tensile elongation and decrease in viscosity of highly filled compounds of surface treated magnesium hydroxide without significant impact on surface and volume resistivity. The decrease in viscosity is significant, and increase in per cent elongation remains significant in formulations containing less than 3 per cent MA-g PE. n

Celanese EVA Polymers 8040 Dixie Highway Florence, KY 40142 USA

6 References

[1] I.O. Salyer, A.S. Kenyon, “Structure and property relationships in ethylene-vinyl acetate copolymers,” J. Polym. Sci. A-1 Polym. Chem., 9: 3083–3103 (1971). [2] S.E. Gerretsen, “Comparative Analysis of Low-Smoke, Zero-Halogen Compounds for Wire and Cable Applications,” SPE ANTEC, Indianapolis 2016., 45-50. [3] T.R. Hull, A. Witkowski, L. Hollingbery. “Fire retardant action of mineral fillers,” Polymer Degradation and Stability, 96 (8), 1462-9 (2011).

Tel: +1 859 372 3277 www.celanese.com

71

www.read-eurowire.com

September 2021