A Highly Transparent Thermoplastic Synthesized from Ethylene that Melts Above 200 °C

Polyolefin‐based thermoplastics are the most widely used polymers and produced in megaton scale. Their applicability depends strongly on the melting point, and a high‐melting ethylene‐based plastic would be highly desirable. Herein, we report the synthesis of isotactic poly(4‐ethylhex‐1‐ene) (P4EH), a highly transparent and ethylene‐based thermoplastic that melts above 220 °C and has an extremely low density. Molecular catalysts were used to synthesize atactic , syndiotactic , and isotactic P4EH with narrow molecular weight distributions. Ziegler–Natta catalysts were used to synthesize isotactic and processable P4EH. Processable i ‐P4EH was used to produce discs, and a transmittance of 92%, a haze of 8% and a clarity of 92% were measured. In addition, a density of 0.86 g cm −3 was observed.