10. Полимерные материалы пластические массы, каучуки и химические волокна.
10. Переведите словосочетания на слух в быстром темпе.
Высокая молекулярная масса natural polymer белки крахмал целлюлоза латекс to be joined sequentially амидная связь small molecules двойная связь между атомами углерода to form a chain быть сделанным из linear chains разветвленные цепи three-dimensional structures повторяющийся структурный фрагмент organic compounds неорганический полимер covalent chemical bond реакция полимеризации alternating silicon and oxygen atoms химическое превращение deoxyribonucleic acid natural polymer современная жизнь solid material соединяться последовательно waste water treatment линейные цепи nutritional emulsion полимерные наполнители plastics and elastomers твердое вещество disposable consumer goods очистка сточных вод high molecular weight образовывать цепь contemporary life трехмерные структуры.
11. Контрольные вопросы.
1. What are polymers?
2. What is the difference between natural and synthetic polymers?
3. What is the origin of the word «polymer»?
4. How are polymers formed?
5. Where can polymers be applied?
12. Передайте основное содержание текстов урока на русском и английском языках.
Unit 2
POLYMERIZATION
1. Прочитайте текст вслух.
Polymerization1is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many forms of polymerization and different systems exist to categorize them. The main categories are addition polymerization (also known as «chain-growth polymerization» or «chain polymerization») and condensation polymerization (also known as «step-growth polymerization» or «step polymerization»).
Addition polymerization involves the linking together of molecules incorporating double or triple chemical bonds. These unsaturated monomers (the identical molecules which make up the polymers) have extra internal bonds which are able to break and link up with other monomers to form the repeating chain. Addition polymerization is involved in the manufacture of polymers such as polyethylene, polypropylene and polyvinyl chloride (PVC). Basic addition polymerization steps are as follows:
Condensation polymerization occurs when monomers bond together through condensation reactions. Generally, a condensation reaction is a chemical reaction in which two molecules combine to form one single molecule, together with the loss of a small molecule. Typically, condensation polymerization reactions can be achieved through reacting2molecules incorporating alcohol, amine or carboxylic acid functional groups:
When an amine reacts with a carboxylic acid, the amide (or peptide) bond is formed with the release of water (hence, condensation polymerization). This is the process through which amino acids link up to form proteins, as well as how kevlar is formed: