EP ORGANIC CHEMISTRY -MOD.MASTERING 18W
EP ORGANIC CHEMISTRY -MOD.MASTERING 18W
9th Edition
ISBN: 9780136781776
Author: Wade
Publisher: PEARSON CO
bartleby

Concept explainers

Question
Book Icon
Chapter 26, Problem 26.34SP
Interpretation Introduction

Interpretation: The mechanism for the formation of urea formaldehyde resin by showing the base catalyzed condensation of urea with formaldehyde is to be proposed.

Concept Introduction: Urea reacts with formaldehyde in the presence of ammonia as a catalyst to form urea formaldehyde resin. This polymerization reaction proceeds through the removal of proton from urea.

To determine: The mechanism for the formation of urea formaldehyde resin.

Blurred answer
Students have asked these similar questions
Plywood and particle board are often glued with cheap, waterproof urea-formaldehyde resins. Two to three moles of formaldehyde are mixed with one mole of urea and a little ammonia as a basic catalyst. The reaction is allowed to proceed until the mixture becomes syrupy, and then it is applied to the wood surface. The wood surfaces are held together under heat and pressure, while polymerization continues and cross-linking takes place. Propose a mechanism for the base-catalyzed condensation of urea with formaldehyde to give a linear polymer, and then show how further condensation leads to cross-linking.
Research in the “unzipping” of poly(vinyl chloride) indicates that certain defects in the polymer contribute to the rate of unzipping. These defects are arrangements of atoms that are different from the arrangements in the repeating unit shown in the condensed formula. Researchers have found that defects involving allylic chlorides and tertiary chlorides, specifically, promote the reaction. Review the mechanism for the unzipping and explain this observation.
In an end-group analysis of a polyester sample prepared from 4-hydroxybenzoic acid, the acid number was found to be 12.4 when it was titrated with standard potassium hydroxide, KOH. Determine the average degree of polymerization of this polyester sample. Given that the molecular weight of KOH= 56.1 g/mol and the molecular weight of the repeating unit of this polyester is 120 g/mol. Determine the osmotic pressure in milliliters of water at 25 °C for a 0.8 % (w/v) aqueous polymer sample solution at 5000 g/mol and 100,000 g/mol respectively. Ignore the nonideality of the solution. Comment on the effectivity. of this measurement technique. [Given that, gas constant, R = 8.3145 J mol¹¹ K-¹]
Knowledge Booster
Background pattern image
Chemistry
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.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
  • Text book image
    Organic Chemistry
    Chemistry
    ISBN:9781305580350
    Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote
    Publisher:Cengage Learning
Text book image
Organic Chemistry
Chemistry
ISBN:9781305580350
Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote
Publisher:Cengage Learning