Vistalon 1703P EPDM for a New Generation of Medium Voltage Cable Insulation

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1 Vistalon 13P EPDM for a New Generation of Medium Voltage Cable Insulation Vistalon 13P is the first in a new generation of ExxonMobil Chemical EP(D)M rubbers utilizing a new diene, Vinyl Norbornene (). is an isomer of ENB (Ethylidene Norbornene) commonly used as the diene in EPDM. However, the pendant vinyl group in has the tendency to incorporate in the polymer chain leading to uncontrolled polymerization and gelation. A recent breakthrough at ExxonMobil Chemical has made it possible to overcome this limitation. A proprietary polymerization process allows the incorporation of significant amounts of without gelation. Vistalon 13P contains about 0.9 wt % of. This diene level is about twenty to thirty percent of the diene content in the EP(D)M currently used in the wire and cable industry. Broad MWD Provided by vs. Other Termonomers Normalized Differential Wt. Fraction ENB Hexadiene Log Molecular Weight

2 Lower Viscosity at High Shear Rates Complex Viscosity (Pa-s) ENB: Vistalon 70, highly processable extrusion grade Frequency (rad/s) Typical Properties: Vistalon Grade Slate Typical Properties Medium Voltage Compound phr Vistalon 13P Calcined Clay 60 Zinc Oxide 5 Red Lead 5 Vinyl Silane 1 Antioxidant 1.5 Low density polyethylene 5 Paraffin Wax 5 Dicumyl Peroxide 5

3 Comparison of and Hexadiene Compounds (60 phr Clay) Physical Properties Tensile Strength 1, /Power Loss 28d/90 C Water Elongation 400 Elongation Retained 28d/1 C HEX Heat Aging Elongation Retained 28d/121 C Comparison of and Hexadiene Compounds (60 phr Clay) Processability Cure Rate rpm Cure State Mass Rate Mass 75 rpm HEX

4 Comparison of and ENB Compounds (60 phr Clay) Processability Cure Rate 75 rpm Cure State Mass Rate Mass 75 rpm ENB Easy processing Vistalon 13P makes wire and cable compounds easy to process, resulting in: High throughput at a given extruder RPM Low die pressure at a given throughput Smooth surface with low adhesion to the insulation shield for ease of stripping Potential to lower filler loading without melt fracture resulting in lower power loss. Variation of Flow Rate with Pressure Drop Variation of Roughness with Mass Rate Volumetric Flow Rate, Q (cc/min) Roughness, R t (microns) Rough (5.5) (7.0) (8.5) Die Pressure Drop, P (psi) 40 Smooth Mass Rate (gm/mm) ENB Hexadiene ENB Hexadiene (arrows indicate melt fracture)

5 High crosslink density tailored for continuous vulcanization Use of as the diene in Vistalon 13P leads to high crosslink density and fast cure rate at a fixed diene and peroxide level (Vistalon 13P is not sulfur curable), when compared to other dienes in use today. The fast cure rate is especially advantageous in the continuous vulcanization (CV) extrusion of cable insulation. In CV, there is a need to match high extrusion throughput with fast cure development to maximize cost effectiveness. The high crosslink density is advantageous for good electrical properties but physical properties, such as elongation to break, can be adversely affected. Therefore it is important to optimize the peroxide level to obtain the right balance between crosslink density and good physical properties. Variation of Cure Properties with Peroxide Level Variation of Physical Properties with Peroxide Level in 60 PHR Clay Compounds Cure (in-lbf) Cure Rate 130 (m - Np) Tensile Stress (psi) Tensile Strength (MPa) Cure Sate % Modulus Peroxide Level (phr) Cure Rate: in-lbf/min or dn.m/min Cure State: in-lbf or dn.m Peroxide Level (phr) Elongation (%) Peroxide Level (phr)

6 Extrudate Appearance 45 phr Clay HEX ENB Smooth Coarse Very Coarse Excellent heat aging The low diene content of Vistalon 13P combined with the need for lower curative levels leads to exceptional retention of physical properties even after prolonged aging at 1 C. Heat Aging of Electrical Compounds (1 C) Heat Aging of Electrical Compounds (121 C) Elongation Change from Unaged Value (%) Elongation Change from Unaged Value (%) Time (Days) Time (Days) Hexadine ENB Hexadine ENB

7 Low electrical loss Vistalon 13P is exceptionally clean. Properties associated with the molecule allow for the manufacture of this polymer in a clean environment with ultra-low levels of metal residues such as calcium, vanadium and iron. This leads to improved wet electrical properties. 00 Hours Wet Electrical Test Polymer Vistalon 13P Hexadiene No. of Trees, (n) Average Tree Length, 1 mm Tree Severity (nxl) Dissipation Factor, DF (%) Wet Electrical Properties of 60 phr Clay Formulations Room Temperature Original Days in 90 C Water ENB (Na+Ca=119) Hexadiene (Na+Ca=2) (Na+Ca=15)