What is suspension polymerization process?
Suspension polymerization is a process in which monomer(s), relatively insoluble in water, is (are) dispersed as liquid droplets with steric stabilizer and vigorous stirring to produce polymer particles as a dispersed solid phase.
Which solvent is used in suspension polymerization?
Explanation: The process of suspension polymerization requires water soluble polymer stabilizers like CMC, PVA or gelatin, etc. to raise medium viscosity and stabilize the suspension.
What is the advantage of suspension polymerization?
The main advantages of suspension polymerization over emulsion systems are that no surfactants, which are difficult to remove from the product, are used, and no ionic end groups are present, which may be unstable during processing at high temperatures.
What is the difference between PMMA and MMA?
The solid form of MMA is called PMMA (poly methyl methacrylate) and has a completely different chemical structure, as well as very different properties. It is not extremely difficult to remove, it does not make an overly hard and rigid nail, and it does not require roughing up of the nail plate.
What is the difference between emulsion and suspension polymerization?
The two differences between emulsion and suspension polymerization are: 1) that a suspension polymerization is a mechanical process, and must have a stabilizing agent until the droplets are far apart, and 2) the emulsion polymerization is a chemical process which requires a surfactant to make the monomer “emulsify.”
Why suspension polymerization is also called as bead polymerization?
Particle properties Suspension polymerization is divided into two main types, depending on the morphology of the particles that result. In bead polymerization, the polymer is soluble in its monomer and the result is a smooth, translucent bead.
Why surfactant is used in suspension polymerization?
The surfactants and electrolytes stabilize the monomer droplets and polymers particles and reduce the viscosity, whereas the water soluble polymers and dispersed (nano)particles increase the viscosity and act as a protective coating. This prevents coalescence or agglomeration of the sticky polymer particles.
Which are the examples of suspension polymerization?
For suspension polymerization, initiation, propogation, and termination take place inside the droplet. examples include the polymerization of methyl methacrylate, and vinyl chloride. The solution polymerization of butadiene, isobutylene and isoprene require a pressure system.
What type of monomer is used in suspension polymerization?
One of the most common suspending agents is polyvinyl alcohol (PVA). Usually, the monomer conversion is complete unlike in bulk polymerization, and the initiator used in this is monomer-soluble.
What are the disadvantages of PMMA?
Limitations of PMMA
- Poor impact resistance.
- Limited heat resistance (80°C)
- Limited chemical resistance, prone to attack by organic solvents.
- Poor wear and abrasion resistance.
- Cracking under load is possible.
What is PMMA polymer used for?
PMMA is used in biomaterial applications such as bone cement, lenses, bone substitutes, and drug delivery systems. It is used to remove wrinkles and scars on skin tissue permanently. In dental implants, polymer material PMMA is substituted for missing dental roots.
What is acrylic PMMA used for?
PMMA or acrylic is a widely used transparent plastic material known for its applications in various markets from car windows, smartphone screens to aquariums. It is a tough plastic, easy to shape and a great alternative to the high cost and less resilient glass.
What is the difference between an emulsion and a suspension?
An emulsion is similar to a suspension only in that it is a mixture of two components. That is where the similarities end, however. Unlike a suspension, which can consist of two components of any phase, an emulsion is a mixture of two liquids.
Which of the following is not used as stabilizers in the suspension polymerization?
which of the following is not used as stabilizers in the suspension polymerisation? Explanation: Heptane is not used as stabilizers in the suspension polymerisation.
Which polymer is prepared by using suspension polymerization technique?
This process is used in the production of many commercial resins, including polyvinyl chloride (PVC), a widely used plastic, styrene resins including polystyrene, expanded polystyrene, and high-impact polystyrene, as well as poly(styrene-acrylonitrile) and poly(methyl methacrylate).
What is the difference between suspension and emulsion polymerization?
What are the advantages of suspension?
Advantages of a Suspension:
- A suspension is a dosage form that can improve the chemical stability of certain drugs.
- Suspension can improve the taste of various unpleasant/bitter tastes of the drug by masking them.
- The drug in suspension exhibits a higher rate of bioavailability than other dosage forms.
What is suspension polymerization?
Suspension polymerization. Suspension polymerization is a heterogeneous radical polymerization process that uses mechanical agitation to mix a monomer or mixture of monomers in a liquid phase, such as water, while the monomers polymerize, forming spheres of polymer. This process is used in the production of many commercial resins,…
What are the initiators used in suspension polymerization?
Suspension Polymerization Vessel The initiators employed for suspension polymerization are mostly peroxides, and in some cases, azo compounds (AIBN). Typical initiators are benzoyl, t-butyl, diacetyl and lauroyl peroxide.
What is suspension polymerization of vinyl fluoride?
In the suspension polymerization technique, liquid vinyl fluoride is suspended in water with the help of a dispersion stabilizer [13]. Polymerization is initiated by an organic peroxide such as diisopropyl peroxydicarbonate below the critical temperature of vinyl fluoride [14,15].
What is the difference between bead and suspension polymerization?
Suspension polymerization is divided into two main types, depending on the morphology of the particles that result. In bead polymerization, the polymer is soluble in its monomer and the result is a smooth, translucent bead.