giass ture (Tg) is the temperature range where a polymer chain gains of the polymer chains depends on (1) the presence of stiffening ated in the polymer backbone and (2) the presence of functional backbone. These functional groups attached to the polymer back For example, polyethylene terephthalate (PET) has a higher glass tra ene adipate. The terephthalic acid moiety in polyethylene ably an inflexible unit. Furthermore, the terephthalic acid moie e and restricts polymer chain mobility. On the other hand, the ene adipate is flexible; thus, making the polymer backbone chains pendant groups in the glass transition temperature is very evident n temperatures of low density polyethylene (LDPE) and polyvinyl al higher glass transition temperature than LDPE attributed to the p OH) which can form strong hydrogen bonds with other polymer ch
giass ture (Tg) is the temperature range where a polymer chain gains of the polymer chains depends on (1) the presence of stiffening ated in the polymer backbone and (2) the presence of functional backbone. These functional groups attached to the polymer back For example, polyethylene terephthalate (PET) has a higher glass tra ene adipate. The terephthalic acid moiety in polyethylene ably an inflexible unit. Furthermore, the terephthalic acid moie e and restricts polymer chain mobility. On the other hand, the ene adipate is flexible; thus, making the polymer backbone chains pendant groups in the glass transition temperature is very evident n temperatures of low density polyethylene (LDPE) and polyvinyl al higher glass transition temperature than LDPE attributed to the p OH) which can form strong hydrogen bonds with other polymer ch
Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
Related questions
Question
Note: I need a simple explanation for this lesson for my presentation. Thank you!

Transcribed Image Text:Properties of Polymers
The properties of the polymers are usually governed by its structure. One such important
property of polymers that is being analysed is the glass transition temperature. The glass transition
temperature (Tg) is the temperature range where a polymer chain gains segmental motion. The
flexibility of the polymer chains depends on (1) the presence of stiffening and flexibilizing groups
incorporated in the polymer backbone and (2) the presence of functional groups attached to the
polymer backbone. These functional groups attached to the polymer backbone is called pendant
groups. For example, polyethylene terephthalate (PET) has a higher glass transition temperature than
polyethylene adipate. The terephthalic acid moiety in polyethylene terephthalate (PET) is
considerably an inflexible unit. Furthermore, the terephthalic acid moiety stiffens the polymer
backbone and restricts polymer chain mobility. On the other hand, the adipic acid moiety in
polyethylene adipate is flexible; thus, making the polymer backbone chains more freely mobile. The
effect of pendant groups in the glass transition temperature is very evident by comparing the glass
transition temperatures of low density polyethylene (LDPE) and polyvinyl alcohol (PVA). PVA has a
relatively higher glass transition temperature than LDPE attributed to the presence of the hydroxyl
group (-OH) which can form strong hydrogen bonds with other polymer chains. Whereas in LDPE,
each polymer chains can only interact with each other via the much weaker London dispersion forces.
The glass transition temperature of polymers also increase due to polymer backbone symmetry and
the presence of crosslinks. Adding additives such as plasticizers, on the other hand, decreases the
glass transition temperatures of polymers.
Table. Approximate glass transition temperatures (Tg) for selected polymers
Glass Transition
Polymer
Chemical Structure
Temperature (Tg)
OH
Polyethylene Adipate
223
Polyethylene
Terephthalate (PET)
342
in
нн
Low density
148
polyethylene (LDPE)
Polyvinyl Alcohol (PVA)
358
НО
Another important property of polymers is its melting temperature. Melting temperature (Tm)
is the temperature range in which the whole polymer chains become mobile. Synonymous to Tg, the
melting temperature is higher for polymers having stiffening groups in the backbone and pendant
groups that may form stronger intermolecular forces of attraction.
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 4 steps with 3 images

Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.Recommended textbooks for you

Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning

Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education

Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning

Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning

Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education

Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning

Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education

Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning

Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY