نوع مقاله : مروری
نویسندگان
1 تهران ، پژوهشگاه پلیمر و پتروشیمی، پژوهشکده علوم ، گروه پلیمرهای زیست‌سازگار صندوق پستی 112-14975
2 تهران ، پژوهشگاه پلیمر و پتروشیمی، پژوهشکده مهندسی، گروه کاتالیست، صندوق پستی 112-14975
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
cyclic olefinic copolymers (COC) include an important class of polyolefins with special properties as soft or hard materials, depending on the content of norbornene monomer in the final copolymer composition. In common commercial copolymers, the amount of norbornene is more than 20% (by mol) which is randomly distributed in the microstructure of the copolymer and gives the final polymers an amorphous and optically transparent structure. An increase in norbornene content in the copolymer structure leads to a corresponding increase in the glass transition temperature (Tg) of the final copolymer. The remarkable optical properties of this type of COC strongly depend on their amorphous structure, which is not limited to the visible light wavelength range, so COCs can be used as transparent polymers in ultraviolet and vislible wavelengths to achieve suitable optically clear products. Due to their higher resistance to chemicals especially polar solvents COCs are used for producing laboratory equipment in a competitive manner with other polymers. On the other hand, COCs are inert biological materials, making them suitable candidates for packaging applications for medicines, including pre-filled syringes. Water is the main solvent used to produce the injectable products, so low water absorption by these copolymers ensures dimensional stability of the final product under ambient conditions. In a highly humid environment, water absorption capacity for COCs is limited to 4 and 10 times less than that of polycarbonate and polymethyl methacrylate polymers, respectively. In this study, after a brief introduction to COCs the polymerization methods by different catalysts are discussed, and the optical mechanical and thermal characteristics of these copolymers are discussed. Finally, the details of COC processing and its applications are mentioned
کلیدواژه‌ها [English]
)