Ch 15Introduction to Polymer Chemistry — Class 12 Chemistry, concept-first.

Polymer chemistry grew into its own branch of chemistry over the last several decades because of the huge body of knowledge built up around it and its ever-widening use in everyday life.

A single polymer can be described from several independent angles at once, so chemists classify polymers along several separate axes rather than one single scheme.

Based on where they come from, polymers fall into three categories. Natural polymers are obtained directly from a natural source and are further split into plant polymers (e.g.

How the monomer units link together -- the chain configuration -- gives a second, independent way to classify a polymer, into three general types (shown in Fig. 15.1).

Polymerization is the fundamental process that converts small, low molecular mass monomers carrying reactive functional groups into a single high molecular mass polymer molecule, joined together throu…

A polymer's mechanical behaviour -- how stretchy, tough or rigid it is -- is governed mainly by the strength of the intermolecular forces between its chains, giving four classes.

Polymers can also be classified by how many distinct kinds of monomer make up their repeating units. Homopolymers contain only one type of repeating unit, usually formed from a single monomer -- polyt…

The final classification basis is biodegradability: whether or not microbes in the environment can break the polymer down.

Having covered the general classification schemes, this section surveys the individual polymers of greatest commercial and everyday importance -- natural rubber and its vulcanization, the two forms of…

Elastomers are popularly known as rubbers; everyday elastomeric articles include balloons, shoe soles, tyres, surgeon's gloves and garden hoses.

Polythene ('polyethylene' being its formal chemical name) is the IUPAC-named simplest and most widely used hydrocarbon thermoplastic, with the repeating structure -[CH2-CH2]n-; it is produced commerci…

Teflon is the common name for polytetrafluoroethylene, made by polymerizing tetrafluoroethylene gas (CF2=CF2) using free-radical initiators such as hydrogen peroxide or ammonium persulphate under high…

Polyacrylonitrile is made by addition (peroxide-initiated) polymerization of the monomer acrylonitrile (CH2=CHCN, a vinyl monomer carrying a nitrile -CN group), giving the repeating structure -[CH2-CH…

Polyamide polymers -- generally known as nylons -- carry the -CO-NH- (amide) linkage between their repeating units, and can be made by condensation polymerization between a dicarboxylic acid and a dia…

Polyester polymers join their repeating units through an ester linkage. The commercially most important polyester fibre is terylene (also called dacron), made by condensation polymerization of ethylen…

Bakelite, the oldest synthetic polymer, is the thermosetting resin obtained by reacting phenol with formaldehyde, catalyzed by acid or base, through a three-stage process (Fig.

Buna-S, also known by its trade name SBR (styrene-butadiene rubber), is an elastomer that is a copolymer of styrene with 1,3-butadiene (Fig.

Neoprene is a synthetic rubber formed by addition polymerization of the monomer chloroprene (2-chloro-1,3-butadiene, CH2=C(Cl)-CH=CH2), which polymerizes rapidly in the presence of oxygen to give the…

Viscose rayon is a semisynthetic fibre made from regenerated cellulose. Cellulose -- a linear polymer of glucose units, molecular formula (C6H10O5)n, conveniently written Cell-OH -- is obtained as woo…

A bulk sample of a polymer is never made of chains of one single, exact length -- it is a complex mixture of molecules with a whole range of molecular masses.

Alongside their enormous range of useful applications, polymers are also blamed for a real environmental cost: most synthetic plastics resist attack by soil microbes and persist in the environment for…

PHBV -- poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) -- is a biodegradable aliphatic polyester copolymer built from two different bifunctional beta-hydroxy carboxylic acid monomers: beta-hydroxy…

Nylon 2-nylon 6 is a biodegradable polyamide copolymer built from two different amino acid monomers: glycine, the simplest amino acid, which contributes the 'nylon 2' portion of the repeating chain (i…

Beyond the individually-named polymers already covered in section 15.3, many further polymers are used extensively across industry and everyday products.

The end-of-chapter questions of this group, exactly as the book prints them.

The end-of-chapter questions of this group, exactly as the book prints them.

The end-of-chapter questions of this group, exactly as the book prints them.

The end-of-chapter questions of this group, exactly as the book prints them.

The end-of-chapter questions of this group, exactly as the book prints them.

The end-of-chapter questions of this group, exactly as the book prints them.

Sample papers and previous-year board questions for this subject.