7. Переведите отрывок на слух по предложению.
In polymer chemistry, a series of condensation reactions take place whereby monomers or monomer chains add to each other to form longer chains. This may also be termed as «condensation polymerization» or «step-growth polymerization». It occurs either as a homopolymerization of an A-B monomer or a polymerization of two co-monomers A-A and B-B. Small molecule condensates are usually liberated, unlike in addition polymerization where there is no liberation of small molecules. A high conversion rate is required to achieve high molecular weights.
In general, condensation polymers form more slowly than addition polymers, often requiring heat. They are generally lower in molecular weight. Monomers are consumed early in the reaction; the terminal functional groups remain active throughout and short chains combine to form longer chains.
8. Переведите предложения на русский язык письменно.
1. In the synthesis of polymers, monomers react and become covalently bonded with one another through the loss of a water molecule.
2. A condensation reaction may be considered as the opposite of a hydrolysis reaction.
3. Most commonly known condensation polymers are proteins, and fabrics such as nylon, silk, or polyester.
4. Addition polymerization involves the breaking of double or triple bonds, which are used to link monomers into chains.
5. Chain growth polymers grow to high molecular weight at a very fast rate.
6. Condensation polymers, unlike addition polymers are biodegradable.
7. The first useful addition polymer was made by accident in 1933 by chemists Reginald Gibson and Eric Fawcett.
8. Addition polymers are widely used today in the form of rubber.
9. Addition polymers are non-biodegradable and hard to recycle.
10. An addition polymer is a polymer which is formed by an addition reaction, where many monomers bond together via rearrangement of bonds without the loss of any atom or molecule.
9. Переведите предложения на английский язык письменно.
1. В реакции поликонденсации могут вступать как один мономер с двумя различными функциональными группами, так и два мономера, несущие различные функциональные группы.
2. Практически все биополимеры (белки, ДНК и РНК, целлюлоза, хитин и пр.) синтезируются в живых организмах поликонденсацией с участием соответствующих комплексов ферментов.