Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 28: Problem 660

Outline all steps in a possible synthesis from non-polymeric starting materials of each of the following polymers. (a) Elastic fibers, used in girdles and bathing suits (Spandex, Lycra). (b) A polyester resin, used in making pipe, boats automobile bodies, etc.

Short Answer

Expert verified
(a) Elastic fibers (Spandex, Lycra): Synthesize Spandex by preparing a long-chain diol (e.g., 1,4-butanediol) and a diisocyanate (e.g., 4,4'-methylenebis(phenyl isocyanate)) as starting monomers. Conduct the polymerization reaction in a suitable solvent under controlled temperature conditions using a step-growth mechanism to form an alternating copolymer containing urethane linkages and polyester segments. (b) Polyester Resin: Synthesize polyester resin by preparing a dicarboxylic acid (or its anhydride, e.g., phthalic anhydride) and a diol (e.g., propylene glycol) as starting monomers. Conduct the polymerization reaction in a suitable solvent under controlled temperature through a step-growth mechanism to form an alternating copolymer containing ester linkages and various pendant functional groups.

Step by step solution

01

Identify the Structure of Spandex

Spandex is a copolymer made up of two types of monomers: a long-chain diol and a diisocyanate. The chemical structure of spandex contains repeating units of polyester and urethane groups.
02

Synthesis of Spandex from Monomers

To synthesize Spandex, we first need to prepare the two starting monomers: a long-chain diol (e.g., 1,4-butanediol) and a diisocyanate (e.g., 4,4'-methylenebis(phenyl isocyanate)). The polymerization process involves the formation of a urethane linkage through a reaction between the-isocyanate groups of the diisocyanate and the hydroxyl groups of the diol.
03

Polymerization Reaction

The polymerization reaction is conducted in a suitable solvent under controlled temperature conditions. The reaction proceeds through a step-growth polymerization mechanism, in which the growth of the polymer chain happens by the stepwise addition of monomers. The diisocyanate and diol monomers react to form an alternating copolymer containing urethane linkages and polyester segments. (b) Polyester Resin
04

Identify the Structure of Polyester Resin

Polyester resins are polymers formed by the condensation reaction between diols and dicarboxylic acids or their derivatives. These polymers usually have a linear backbone with ester linkages and various pendant functional groups. The monomers involved are typically an aromatic dicarboxylic acid (e.g., phthalic anhydride) and a diol (e.g., propylene glycol).
05

Synthesis of Polyester Resin from Monomers

To synthesize a polyester resin, we first need to prepare the starting monomers: a dicarboxylic acid (or its anhydride) and a diol. The polymerization process involves the formation of ester linkages through a condensation reaction between the carboxylic acid groups (or the anhydride) and the hydroxyl groups of the diol.
06

Polymerization Reaction

The polymerization reaction is conducted in a suitable solvent and under controlled temperature conditions. The reaction proceeds through a step-growth polymerization mechanism in which the growth of the polymer chain happens by the stepwise addition of monomers. The dicarboxylic acid and diol monomers react to form an alternating copolymer containing ester linkages and various pendant functional groups, depending on the specific monomers used.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Natural rubber is attacked readily by ozone. If the resulting material is treated with \(\mathrm{H}_{2} \mathrm{O}_{2}\) in acetic acid, the major product isolated is levulinic acid \(\left(\mathrm{C}_{5} \mathrm{H}_{8} \mathrm{O}_{3}\right)\). (a) What is the structure of levulinic acid? (b) If a rubber plant is fed radioactive sodium acetate labeled only at the acetate methyl \(\left({ }^{*} \mathrm{CH}_{3} \mathrm{CO}^{-}{ }_{2} \mathrm{Na}^{+}\right)\), radioactive rubber can be obtained from the latex of the plant after a short time. Degradation of this rubber by ozone yields radioactive levulinic acid. Which specific carbon atoms of the levulinic acid would you expect to be radioactive?

High-pressure polyethylene differs from polyethylene, made with the aid of Ziegler catalysts, in having a lower density and lower \(\mathrm{T}_{\mathrm{m}} .\) It has been suggested that this is due to branches in the chains of the high-pressure material. Explain how such branches might arise in the polymerization process and how they would affect the density and \(\mathrm{T}_{\mathrm{m}}\).

Linseed oil and tung oil, important constituents of paints, are esters derived from acids that contain two or three double bonds per molecule: 9,12 -octadecadienoic acid, for example. On exposure to air, paint forms a tough protective film; oddly enough, after the initial rapid evaporation of solvent, this 'drying" of paint is accompanied by a gain in weight. What kind of process do you think is involved? Be as specific as you can be.

Show how the successive use of cation- and anionexchange resins could be used to remove sodium chloride from water.

When formaldehyde is polymerized to a linear polymer in heptane solvent, with \(\left(\mathrm{C}_{6} \mathrm{H}_{5}\right){ }_{3} \mathrm{P}\) or a proton as a catalyst, it yields a thermally unstable material (A) that unzips readily to re-form formaldehyde. However, if the end of the polymer is 'capped", the product is a highly crystalline, tough polymer. The example below, \(\mathrm{B}\), is called Delrin and is already replacing nylon as a molding resin. Suggest a reason for the stability gained by capping the polymer.
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Chemical Analysis

Read Explanation

Kinetics

Read Explanation

Organic Chemistry

Read Explanation

Nuclear Chemistry

Read Explanation

Chemistry Branches

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free