What are Polymers? (Что такое полимеры?). А. Н. Безруков

– repeating material portion – внутримолекулярный – complex network – supramolecular level – первичная структура – двойная спираль.

      11. Контрольные вопросы.

      1. What scale of polymer structure and properties is called supramolecular?

      2. Describe two main types of organization in supramolecular polymer aggregates.

      3. What is a crystalline phase?

      4. Which one, HDPE or LDPE, is more amorphous?

      5. Are polymer crystals more regular than the low molecular weight ones?

      12. Передайте основное содержание текстов урока на русском и английском языках.

      Unit 4

      PHASE BEHAVIOR OF POLYMERS

      1. Прочитайте текст вслух.

      Consider a polymer which is slowly cooling down. At a certain temperature, the average kinetic energy of macromolecules no longer exceeds the binding energy between neighbouring molecules and the growth of organized solid crystal begins. Formation of an ordered system takes a certain amount of time since the molecules must move from their current location to energetically preferred points at crystal nodes.

      As temperature falls, molecular motion slows down further and, if the cooling rate is fast enough, molecules never reach their destination – the substance enters dynamic arrest and a disordered, glassy solid (or supercooled liquid) forms. Such arrest apparently takes place at a certain temperature, which is called the glass transition temperature (Tg).