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+ Polymer science
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Kifayat Kifayatkhan

What factors affect the degree of crystallinity in polymers and why?

Curious  Follow

Hello everyone.

Factors affecting crystallinity:

1.Length of the chain:Long chain ( high degree of polymerisation) are less likely to crystalize.

2.Branching:Branched chains are less likely to crystalize .

3.Copolymer :

Copolymer are different types :

Random copolymer does not show crystallinity.

Block copolymer does not show crystallinity.

Graft copolymer does not show crystallinity.

Alternating copolymer shows the crystallinity

4.Tacticity or storeoisomerism.

Atactic does not show crystallinity.

Syndiotactic show crystallinity.

Isotactic show crystallinity.

5.plastizers :

Low molecular weight addiives to a polymer to prevent crystallization by keeping chains separated from one another.

Crystalline having brittleness.

Amorphous have plasticity.

Thank you everyone.

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Brian Bilson  Follow

1.) Polymer structure and nature of functional groups: Crystallinity in polymers is governed by the extent of chain ordering, or chain folding. If the side groups of the polymer backbone are large and heavy, chain movement and folding is hindered, which reduces the probability of forming crystalline domains.

2.) Arrangement (Tacticity): In continuation of the above, chains (or side groups) that are arranged in an ordered manner can pack together more efficiently which leads to increased crystallinity.

3.) Secondary bonding: Both inter- and intra-molecular Hydrogen bonding play important roles in polymer crystallinity. With increased chain to chain secondary bonding, there is an increase in crystallinity of the polymer, making the material stronger.

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