Abstract
<title>Abstract</title> <p>The production of polymeric materials that are both strong and lightweight has long been a primary objective in the fiber and film industries. Accurate control of the necking process and the deformation of the entanglement network is essential for effective material stretching. We systematically examine the nonlinear mechanical behavior of neat polyethylene and compare it with that of low-entangled bimodal polyethylene blends. Our findings indicate that the necking mode is strongly influenced by the ratio of the crystalline phase strength to the strain-hardening modulus. Highly dilute polyethylene exhibits sudden, pronounced necking during room-temperature stretching, thereby restricting continuous thinning and limiting the achievable Hencky strain. Although highly dilute PE fractures at low draw ratios at room temperature, the same material exhibits more uniform, rubber-like deformation, resulting in more efficient drawing and higher strength, allowing the preparation of high-modulus fibers. These results challenge the traditional belief in the fiber and film sectors that "higher draw ratios lead to higher strength.” Instead, the path to high-performance materials relies on the precise control of the deformation of the physical entanglement network.</p>