Skip to main content

Poly ( vinyl acetate).

Poly (vinyl acetate) or PVA or PVAc.

  • Poly(vinyl acetate) is a synthetic polymer.
  • It is also known as poly(ethenyl ethanoate), wood glue, white glue, carpenter's glue, school glue, PVA glue, Elmer's glue.
  • It is prepared by the free radical polymerisation of vinyl acetate in the presence of free radical initiator like benzoyl peroxide.
    This image shows synthesis of poly(vinyl acetate) from vinyl acetate.
    Poly(vinyl acetate).
  • Poly(vinyl acetate) is an amorphous polymer.
  • It is a colourless, transparent, soft and sticky material.
  • It is soluble in organic solvents.
  • It is resistant to heat but turns slightly yellow on prolonged storage above 120°C.
  • It is used in adhesives, lacquers.
  • It is used for making chewing gums, surgical dressings etc.
  • It is used for the manufacture of poly(vinyl alcohol) etc.
  • It is used in water based emulsion paints.
    This image shows uses of poly(vinyl acetate) in adhesives, lacquers, surgical dressings,water based emulsion paints and chewing gums.
    Uses of poly(vinyl acetate).

Questions on Poly(vinyl acetate);

Q1) What is Poly(vinyl acetate)?
Ans) Poly(vinyl acetate) is a synthetic polymer. 
Q2) What is the monomer of Poly(vinyl acetate)?
Ans) Vinyl acetate is the monomer of Poly(vinyl acetate).
Q3) How is Poly(vinyl acetate) prepared?
Ans) Poly(vinyl acetate) is prepared by the free radical polymerisation of vinyl acetate in the presence of free radical initiator like benzoyl peroxide.
Q4) Write some properties of Poly(vinyl acetate)?
Ans) Some properties of Poly(vinyl acetate) are given below;
1) It is a colourless, transparent, soft and sticky material.
2) It is soluble in organic solvents.
3) It is resistant to heat but turns slightly yellow on prolonged storage above 120°C.
4) Poly(vinyl acetate) is an amorphous polymer.
Q5) Write some uses of Poly(vinyl acetate)?
Ans) Some uses of Poly(vinyl acetate) are given below;
1) Poly(vinyl acetate) is used in adhesives, lacquers.
2) Poly(vinyl acetate) is used for making chewing gums, surgical dressings etc.
3) It is used for the manufacture of poly(vinyl alcohol) etc.
4) Poly(vinyl acetate) is used in water based emulsion paints. Next


Comments

Popular posts from this blog

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 viscosity vs concentr

Determination of molecular weight by Light scattering method.

Determination of molecular weight by Light scattering method. Due to big size macromolecules in solution, turbidity is produced. The light rays get scattered, when pass through macromolecule solution due to turbidity. The turbidity T is given by Where I₀ is the intensity of incident light. Iₜ is the intensity of transmitted light after passing through a solution of length l.        In case of proteins or higher polymers the turbidity is small and is determine from the intensity of light scattered at 90° to the beam. This can be done by using a simple photometer as shown in figure below. Turbidity increase with increase in concentration as well as molecular weight. The Turbidity is related to molecular weight by the equation given by Debye. Hc/T=1/M+2Bc Where B is second virial coefficient and H is a constant. If we plot a graph between Hc/T vs c we get a straight line with intercept 1/M. Thus This curve was plotted by Zimm, so is called Zimm's Curve. Thus the c

Kinetics of copolymerisation and Composition of copolymer.

Kinetics of copolymerisation and Composition of copolymer. We must know that Where r₁ and r₂ are the reactivity ratio's for the given pair of monomers. Where the above equation is called Copolymerisation equation and it gives the copolymerisation composition without using radical concentration. Types of copolymerisation ( kinetics significance) Let us take the reactivity ratio's product of monomers i.e Product of reactivity ratios. Depending on whether this product is less, greater or equal to unity copolymers are divided into three types. 1)Ideal copolymerisation Here the product of reactivity ratios is equal to unity, i.e r₁r₂=1 2) Alternating copolymerisation Here the product of reactivity ratios is equal to zero, i.e r₁r₂=0. 3)Block copolymerisation Here the product of reactivity ratios is greater than 1, i.e r₁r₂>1.