Types of polymerisation, Mechanical Engineering

Types Of Polymerisation

When some of bifunctional molecules connect in a chain structure, the reaction is termed as addition polymerisation.  However, these polymerizations do not take place on its but has to be initiated, propagated and after that terminated. Presence of split H2O2 or 2HO usually initiates the reaction. Hydrogen peroxide is heated to split in two free radicals 2HO that initiates polymerisation.  The energy of the chain polymer is lower than that of the independent monomers such form the chain and thus the chain grows in length fast after initiation. By addition of trace impurity the reaction is terminated. The reaction termination may airse because of two ends of joining of the chain or because of supply of exhaustion of the monomers also. Ethylene or C2H4 polymerising in polyethylene and vinylchloride or C2H3Cl polymerising in polyvinyl chloride are the illustrations of addition polymers.

The improvements in polymer technology have led to the knwoing that monomers of two various types can join in a single chain in co-polymerisation.  For illustration, monomers of vinylaecetate and vinylchloride form a chain of copolymers as demonstrates in figure of Co-polymerisation of Vinylchloride or C2H3Cl and Vinylacetate or OCOCH3. Vinylacetate molecule along with dual bond between oxygen and carbon is also demonstrates in same figure. This double bond opens into two bonds to join along with another opened bond of carbon of vinylchloride.

                                                                    151_Polymerization 4.png

                                 Figure: Co-polymerisation of Vinylchloride or C2H3Cl and Vinylacetate or OCOCH3

A copolymer is greatly like a solid solution in crystalline materials because its properties are very much dissimilar than those of constituents.A third type of polymerisation reaction happens when a second non-polymerisation molecule is generated as a byproduct. This reaction is termed as condensation polymerization.  The genearl byproducts of condensation polymerisation are water, CH3OH or HCl. In a characteristic reaction of polycondensation among hexamethylenediamine and adipic acid long chain nylon molecules are produced along with water as a byproduct.

Posted Date: 2/27/2013 4:39:55 AM | Location : United States







Related Discussions:- Types of polymerisation, Assignment Help, Ask Question on Types of polymerisation, Get Answer, Expert's Help, Types of polymerisation Discussions

Write discussion on Types of polymerisation
Your posts are moderated
Related Questions
Structural Steels Low alloy steels are utilized for structural causes. That type of steels is needed to possess high yield stress, excellent ductility and high fatigue resist

CLASSIFICATION OF POWER SOURCES ACCORDING TO CONSTRUCTION & DESIGN To give the desired output a power source may be constructed with different components. Therefore, a classifi

VISUAL REALISM: Hidden line and surface removal eliminates the ambiguities of the displays of three-dimensional models and is considered the first step toward visual realism.

A "swing" ride at a carnival consists of chairs that are swung in a circle by 12.0 m cables attached to a vertical rotating pole, as the drawing shows. (θ = 60.0°) Suppose the tota

Water flows into the sink shown in figure 5 at a flow rate of 8 L/min. If the drain is closed, the water will eventually flow through the overflow drain holes rather than over the

Draw a graph of velocity and shear stress distribution profile for viscous flow between two parallel plates.

A parallel plate capacitor is charged to a total charge Q and then the battery is removed. A slab of material with dielectric constant ? is inserted between the plates. (Justify y

Working of stream engine: The high pressure steam from boiler is supplied to the steam chest. The high pressure steam enters cylinder through inlet port and exerts pressure on


A pump is used to deliver discharge of 0.05 m 3 /s from a river to a storage reservoir. The system consists of 500 m of 0.15 m cast iron pipe with a 90 o bend with a rad