11.8 Polymers

Polymers are large molecules built up from many smaller molecules which called monomers.

1. Addition polymerisation

n(alkene) → addition polymer

2. Condensation polymerisation

(1) Polyester

dicarboxylic acid + diol → polyester

eg: PET (polyethylene terephthalate, 聚对苯二甲酸二甲酯. This name is not required to memorize.)

PET can be hydrolysed back monomer for re-polymerising.

(2) polyamide

dicarboxylic acid + diamine → polyamide

3. Summary of different types of polymers

Addition polymersCondensation polymers
Reactant
(Monomer)
a single monomer
“C=C”
two monomers
“2 x COOH” and “2 x OH”
or “2 x COOH” and “2 x NH2
Reaction
(taking place)
addition
opening “C=C”
condensation
loss of small molecule (eg: H2O)
Productsa single product: polymer
non-biodegradable
resistant to acids
two products: polymer + small molecule
biodegradable (nylon: 40-50 yrs)
PET can be hydrolyzed by acids or alkalis.

4. Natural polymer: Proteins

Amino acid → proteins
There are 20 different amino acids, and listed in the following table. (You are not required to memorized the detailed name and structure of a specific amino acid.)

Amino acids can be described by the following general structure.


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《 “11.8 Polymers” 》 有 3 条评论

  1. Jathnason 的头像
    Jathnason

    老师,你这要背的这些元素也太多了,要昏过去了

    1. Chemistry Teacher (Wang J.J.) 的头像

      哪些元素要背了啊?特地还写了这些内容不需要知道,仔细看一下

      1. Jathnason 的头像
        Jathnason

        我的我的,看错了

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