Ring opening Polymerisation.

Ring opening Polymerisation

Ring opening Polymerisation have some features similar with addition and condensation polymerisation mechanism, they show at least one important different features from each of these polymerisation. In ring opening polymerisation the small molecules does not split up, while in condensation polymers it does. This Polymerisation is different from olefins polymerisation , in the sense that the driving force for this polymerisation is not derived from the loss of unsaturation of monomers.

This polymerisation generally gives linear compounds. These have generally same composition as that of the monomers. Not all Cyclic compounds undergo ring opening polymerisation. The general ring opening polymerisation is given by equation below.

Ring opening polymerisation.

Where X is heteroatom or a group.

Some common example of ring opening polymerisation reaction.

Examples of ring opening polymerisation.

Comments

Polylactic acid/PLA.

Polylactic acid/PLA. Polylactic acid is a biodegradable thermoplastic polymer . Polylactic acid is obtained from lactic acid monomer. Polylactic acid. Polylactic acid is stable to UV radiation. Polylactic acid has good resistance to moisture. Polylactic acid has good elasticity. Polylactic acid is an aliphatic polyester . It can be used as a food packaging polymer. Polylactic acid is suitable for textile fibre applications such as shirts, carpets, sportswear etc. Polylactic acid is used in implants and medical devices (screws, sutures etc). Polylactic acid is suitable for use in floor mats. Uses of Polylactic acid. Questions on Polylactic acid/PLA; Q1) What is Polylactic acid? Ans) Polylactic acid is a biodegradable thermoplastic polymer. Q2) What is the monomer of Polylactic acid? Ans) Polylactic acid is obtained from lactic acid monomer. Q3) Write some properties of Polylactic acid? Ans) Some properties of Polylactic acid are given below; ...

Determination of molecular weight by osmotic pressure method

Determination of molecular weight by osmotic pressure method. Osmotic pressure method is also called membrane osmometry. This method is widely used to determine the number average molecular weight of polymers. This method is based on the phenomenon of osmosis. If a pure solvent is separated from a solution through a semipermeable membrane, due to concentration (chemical potential) difference between the solvent and solution, the solvent will flow into the solution through semipermeable membrane. The pressure applied on the solution to completely stop the flow of solvent into it through semipermeable membrane is called osmotic pressure. The theory of osmotic pressure also applies to a solution of polymers. Ordinary solution obeys Van't Hoff equation i.e π=cRT/M Where π is osmotic pressure, c is concentration in mass per unit volume, R is gas constant, T is temperature and M is molar mass. The polymer solution are non ideal. Taking into account their deviation and us...

Determination of molecular weight of polymers by viscosity method.

Determination of molecular weight of polymers by viscosity method. It is a simple method for determining the molecular weight of polymers. Addition of polymers in the solvent increases the viscosity of the solvent, due to introduction of inhomogeneities by the polymers. If η₀ is the viscosity of the solvent and η is the viscosity of the solution at the same temperature, then the relative viscosity is given by Relative viscosity. Specific viscosity: It is defined as the relative increase in viscosity and is given as Specific viscosity. Reduced viscosity: It is defined as the relative increase in viscosity per unit concentration (C) of polymer and is given as Reduced viscosity. Intrinsic viscosity: The reduced viscosity is dependent on concentration (C). If a graph is plotted between reduced viscosity vs concentration then the extraplotation value when C=0 is called intrinsic viscosity. Intrinsic viscosity. Graph of reduced vi...

Polymers

Search This Blog