this ppt contain physical, mechanical and chemical properties of the polymer compound and their mechanical weight distribution. this ppt make an idea about all of the mentioned agenda.

1. • Submitted by
Keshob kumer Ghose
ID: 2016000300001
Section: A
Batch: 27
• Submitted to
Sonia Zaman
Senior lecturer
Department of pharmacy
Southeast university
Presentation on polymer science

4. POLYMER SCIENCE
Keshob kumer Ghose

5. FUNCTION OF POLYMER
• Suspending agent
• Emulsifying agent
• Adhesive
• Coating
• adjuvant

6. GOAL OF THIS PRESENTATION
• Physical properties
• Chemical properties
• Mechanical properties
• Molecular weight
• distribution
MARTIN’S PHYSICAL PHARMACY AND PHARMACEUTICAL SCIENCES

7. DEPENDENCE OF POLYMERS
• structure
• molecular weight
• Linearity
• intra- and intermolecular interactions
MARTIN’S PHYSICAL PHARMACY AND PHARMACEUTICAL SCIENCES

8. PHYSICAL PROPERTIES
The physical properties of a polymer, such as its strength and flexibility depend on:
• Chain length - in general, the longer the chains the stronger the polymer.
• Side groups - polar side groups give stronger attraction between polymer chains,
making the polymer stronger.
• Branching - straight, un branched chains can pack together more closely than highly
branched chains, giving polymers that are more crystalline and therefore stronger.
• Cross-linking - if polymer chains are linked together extensively by covalent bonds,
the polymer is harder and more difficult to melt.
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9. CRYSTALLINE AND AMORPHOUS
POLYMERS
• Crystallinity provide packaging in which it act as a barrier.
• Semi crystallinity or also known as amorphous provide coating that ensure the drug
in its particular environment.
• Crystal is formed due to the linearity and intrapariticular attraction stabilize the
polymer which ensure sharp melting point.
• Amorphous polymer compound has no sharp melting.
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10. CRYSTALLINE AND AMORPHOUS
POLYMERS
• From a pharmaceutical prospective,
• good barrier properties are needed when polymers are used as a packaging
material or as a coating. Crystallinity increases the barrier properties of the polymer.
Small molecules like drugs or solvents usually cannot penetrate or diffuse through
crystalline domains. Therefore, crystalline polymers display better barrier properties
and durability in the presence of attacking molecules.
• Amorphous provide drug release.
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11. THERMAL TRANSITIONS
• Tm represents the first order transition state.
• Tg represents the second order transition state.
• These two thermal transitions reflect the structural movement of the crystalline and
amorphous regions of a polymer chain.
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12. MARTIN’S PHYSICAL
PHARMACY AND
PHARMACEUTICAL
SCIENCES

13. GLASS TRANSITION TEMPERATURE
• Tg is an important factor for solid dosage forms:
• Nicotine gum which is the perfect example of this one.
• Segmental motion affect Tg.
• At a given weight, a low density polymer occupies more volume as compared with
its high-density counterpart. This means the polymer chain in general and the chain
segments in particular can move with more ease resulting in a lower Tg value.
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14. PLASTICIZED POLYMERS
• A plasticizer is added to a polymer formulation to enhance its flexibility and to help
its processing. It facilitates relative movement of polymer chains against each other.
The addition of a plasticizer to a polymer results in a reduction in the glass
transition temperature of the mixture. Di-Ethylhexyl Phthalate.
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15. MOLECULAR WEIGHT
• Addition of a monomer to a growing macroradical during polymer synthesis occurs
by a diffusion or a random walk process. Monomers may or may not be added
equally to the growing macroradicals. As a result, a polymer batch may contain
polymer chains with different lengths (molecular weights) and hence different
molecular weight distributions. A very narrow molecular weight distribution is very
much desired for a polymer that is intended to be mechanically strong.
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16. MECHANICAL PROPERTIES
• Depending on their structure, molecular weight, and intermolecular forces, polymers
resist differently when they are stressed. They can resist against stretching (tensile
strength), compression (compressive strength), bending (flexural strength), sudden
stress (impact strength), and dynamic loading (fatigue). With increasing molecular
weight and hence the level of intermolecular forces, polymers display superior
properties under an applied stress. As far as structure is concerned, a flexible
polymer can perform better under stretching whereas a rigid polymer is better
under compression.
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17. MECHANICAL PROPERTIES
Strength
In simple words, the strength is the stress required to break the sample. There are
several types of the strength, namely
• tensile (stretching of the polymer)
• compressional (compressing the polymer)
• flexural (bending of the polymer)
• torsional (twisting of the polymer)
• impact (hammering) The polymers follow the following order of increasing
strength: linear < branched < cross-linked < network
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18. stress
Break
Elongation
Percent Elongation to Break (Ultimate Elongation):
It is the strain in the material on its breakage. It measures the percentage change in the length
of the material before fracture. It is a measure of ductility.
Mechanical properties
http://onlinelibrary.wiley.com/doi/10.10
02/9781118950623.app1/pdf

19. MECHANICAL PROPERTIES
• Toughness: The toughness of a material is given by the area under a stress–strain
curve
stress
Break
Elongation
http://onlinelibrary.wiley.com/doi/10.100
2/9781118950623.app1/pdf

20. CHEMICAL PROPERTIES
• Compared to conventional molecules with different side molecules, the polymer is
enabled with hydrogen bonding and ionic bonding resulting in better cross-linking
strength.
• Dipole-dipole bonding side chains enable the polymer for high flexibility.
• Polymers with Van der Waals forces linking chains are known to be weak, but give
the polymer a low melting point.
https://byjus.com/chemistry/polymers/

21. MOLECULAR WEIGHT AND POLYMER
PROPERTIES
• Polymer melts and polymer solutions are handled with more difficulty as their
molecular weight increases. This is due to a phenomenon called entanglement,
which affects the flow of the polymer chains.
• As molecular weight increases, polymer chains are more likely entangled into each
other at certain molecular weights.
• This results in poor polymer flow either in solid state (as a melt) or in solution state
(as a solution). For many applications, there is a working range of molecular weights
that a given polymer in solid or solution state can successfully be processed.
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22. MOLECULAR WEIGHT DISTRIBUTION
There are two fundamental properties of polymers:
• chemical structure
• molecular weight distribution
These two structural characteristics determine all properties of a polymer.
http://polymerdatabase.com/polymer%20physics/Molecular%20Weight.html

23. MOLECULAR WEIGHT AND
DISTRIBUTION
• The average molecular weight or molar mass of a polymer depends on the
molecular weight distribution, which, in turn, depends on the type of monomer and
the polymerization process conditions.
• The average molecular weight can be expressed as a number, weight, or viscosity
average molecular weight.
• The ratio of weight and number molecular weight is called the polydispersity index.
It is a measure for the broadness of a molecular weight distribution of a polymer.
http://polymerdatabase.com/polymer%20physics/Molecular%20Weight.html

24. THANK YOU