The Polymer Society of Korea

김창근 (대한전선)

김창근 (대한전선)

Polypropylene (PP) is a promising insulating material for power cables due to its superior performance. Block PP, offering greater flexibility than homo PP, is investigated for insulation applications. However, stress whitening–induced degradation remains a concern. In this study, PP-based composites were prepared with a fixed total fraction of elastomer and Olefin Block Copolymer (OBC), while varying the OBC content to assess effects on electrical and mechanical properties. Increasing OBC content improved breakdown strength but also raised flexural modulus. Controlling flexural modulus is essential to prevent whitening because excessive modulus hinders cable winding. Currently, quantitative standards for the flexural modulus of PP-based cable insulators are insufficient in existing power cable specifications. Therefore, these results provide valuable direction for future material design and standardization efforts in the cable insulation field.