--%>
Assignment Help - homework help

What are various structure based polymers?

This classification of polymers is based upon how the monomeric units are linked together. Based on their structure, the polymers are classified as:


1. Linear polymers: these are the polymers in which monomeric units are linked together to form long straight chains. The polymeric chains are stacked over one another to give a well packed structure. As a result of close packing, such polymers have densities, high tensile strength and high melting points. Common examples of such type of polymers are polyethylene, nylons and polyesters.

2. Branched chain polymers: in this type of polymers, the monomeric units are linked to constitute, long chains (called the main-chain). There are side chains of varied lengths which comprise branches. Branched chain polymers are irregularly packed and thus, they have low density, lower tensile strength and lower melting points as compared to linear polymers. Amylopectin and glycogen are common examples of this type.

3. Network polymers or Cross-linked: in this type of polymers, the monomeric units are linked together to constitute a three-dimensional network. The links involved are called cross-links. Cross-linked polymers are hard, rigid and brittle because of their network structure. Common examples of this type of polymers are Bakelite, melamine formaldehyde resin, etc.

 

 

   Related Questions in Chemistry

  • Q : Molal elevation constant of water The

    The boiling point of 0.1 molal aqueous solution of urea is 100.18oC  at 1 atm. The molal elevation constant of water is: (a) 1.8    (b) 0.18   (c) 18    (d) 18.6Answer: (a) Kb

    		•
  • Q : What do you mean by the term enzymes

    What do you mean by the term enzymes? Briefly illustrate it.

    		•
  • Q : Explain Second Order Rate Equations.

    Integration of the second order rate equations also produces convenient expressions for dealing with concentration time results.A reaction is classified as second order if the rate of the reaction is proportional to the square of the concentration of one o

    		•
  • Q : Amines why o-toluidine is a weaker base

    why o-toluidine is a weaker base than aniline?

    		•
  • Q : Some basic concepts of chemistry an

    an atom of an element is 10.1 times heavier than the mass of a carbon atom.What is its mass in amu?

    		•
  • Q : Problem based on molality of glucose

    Select the right answer of the question. If 18 gm of glucose (C6H12O6) is present in 1000 gm of an aqueous solution of glucose, it is said to be: (a)1 molal (b)1.1 molal (c)0.5 molal (d)0.1 molal

    		•
  • Q : Freezing point of equimolal aqueous

    The freezing point of equi-molal aqueous solution will be maximum for:            (a) C6H5NH3+Cl-(aniline hydrochloride)  (b) Ca(NO3

    		•
  • Q : State substituted hydrocarbon Elaborate

    Elaborate a substituted hydrocarbon?

    		•
  • Q : Donnan Membrane Equilibria The electric

    The electric charge acquired by macromolecules affects the equilibrium set up across a semipermeable membrane.Laboratory studies of macromolecule solutions as in osmotic pressure and dialysis studies confine the macromolecules to one compartment while allo

    		•
  • Q : Explain reactions of carbonyl oxygen

    In these reaction oxygen atom of carbonyl group is replaced by either one divalent group or two monovalent groups. Reaction by ammonia derivatives: aldehydes and ketones react with a number of ammonia derivatives such as hydroxylaminem hydrazine, semicarbazide etc. in weak acidic medium.

    		•