EP ORGANIC CHEMISTRY -MOD.MASTERING 18W
9th Edition
ISBN: 9780136781776
Author: Wade
Publisher: PEARSON CO
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
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
To determine: The mechanism for the formation of urea formaldehyde resin.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents 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]
Chapter 26 Solutions
EP ORGANIC CHEMISTRY -MOD.MASTERING 18W
Ch. 26.2A - Show the intermediate that would result if the...Ch. 26.2A - Prob. 26.2PCh. 26.2A - Prob. 26.3PCh. 26.2B - Prob. 26.4PCh. 26.2B - Prob. 26.5PCh. 26.2B - Chain branching occurs in cationic polymerization...Ch. 26.2C - Prob. 26.7PCh. 26.2C - Prob. 26.8PCh. 26.2C - Chain branching is not as common with anionic...Ch. 26.3 - Prob. 26.10P
Ch. 26.5 - Prob. 26.11PCh. 26.6 - Prob. 26.12PCh. 26.7A - Prob. 26.13PCh. 26.7B - Prob. 26.14PCh. 26.7B - Prob. 26.15PCh. 26.7C - a. Propose a mechanism for the reaction of...Ch. 26.7C - Prob. 26.17PCh. 26.7D - Prob. 26.18PCh. 26.7D - Prob. 26.19PCh. 26.7D - Prob. 26.20PCh. 26 - Prob. 26.21SPCh. 26 - Prob. 26.22SPCh. 26 - Poly(trimethylene carbamate) is used in...Ch. 26 - Prob. 26.24SPCh. 26 - Urylon fibers are used in premium fishing nets...Ch. 26 - Prob. 26.26SPCh. 26 - Prob. 26.27SPCh. 26 - Polyoxymethylene (polyformaldehyde) is the tough,...Ch. 26 - Prob. 26.29SPCh. 26 - Prob. 26.30SPCh. 26 - Prob. 26.31SPCh. 26 - Prob. 26.32SPCh. 26 - Prob. 26.33SPCh. 26 - Prob. 26.34SPCh. 26 - The polyester named Lactomer is an alternating...Ch. 26 - Prob. 26.36SP
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.Similar questions
- Briefly discuss emulsion and suspension polymerization techniques.arrow_forwardShow the differences between the chain-growth and step-growth mechanisms of polymerization.arrow_forwardDiscuss the effects of solvent polarity in the anionic polymerizations of (a) styrene initiated with sodium naphthalenide and (b) 1,3-butadiene initiated with n-butyllithiumarrow_forward
- Write a mechanism for the acid-catalyzed polymerization of 1,4- benzenediisocyanate and ethylene glycol. To simplify your mechanism, consider only the reaction of one -NCO group with one -OH group. no=C=N + n HO -N-C- HO, H. 1,4-Benzenediisocyanate Ethylene glycol A polyurethanearrow_forwardProvide the mechanism for the step-growth polymerization of citric acid and ethylene glycol to form poly (ethylene glycol)-citrate. Show all steps.arrow_forwardStyrene can autoinitiate free radical polymerization and form polystyrene in the absence of an initiator. At temperatures >100 °C, radicals form due to homolysis of the T bond in the vinyl group. In the study of this reaction, researchers have found 1,2-diphenylcyclobutane in samples of heated styrene. The following mechanism for the formation of 1,2-diphenylcyclobutane has been proposed: Step 1: Homolysis of the vinyl T bond in a styrene molecule Step 2: Homolysis of the vinyl T bond in a second styrene molecule Step 3: Tail-to-tail addition of the radicals from Steps 1 and 2 Step 4: Radical coupling of the diradical formed in Step 3 (a) Use curved arrow notation to show the steps in this mechanism. (b) Are the steps in this mechanism consistent with those for free radical polymerization? (c) Why is the use of an initiator such as benzoyl peroxide more efficient in the synthesis of polystyrene than autoinitiated polymerization?arrow_forward
- Is there any difference between post-processing and post-treatment?arrow_forwardOrganic chemistry: brief introduction of interfacial polymerization by nylonarrow_forwardWhat is the basic mechanism of an Anionic polymer (acrylic acid based as carbomers) in regards to function and “activation”? How do they work and thicken?arrow_forward
- Chemicals for which the commercially important plastic resins are derived are themselves derived from natural products that are quite plentiful;These raw materials include coal, water lime stone, sulfur, salt and petroleum. True or false.arrow_forwardMacromolecules can also be formed from cyclic monomers such as cyclic hydrocarbons, ethers, esters, amides, siloxanes, and sulfur (eight-membered ring). Thus, ring-opening polymerization is of particular interest, since macromolecules of almost any chemical structure can be prepared. Choose two of the above type polymers to explain the mechanism and chemical reaction of polymerization process.arrow_forwardIn a groundwater 1,1,1 trichloroethane, hexachlorobenzene and 1,1,2 trichloroethane have leached from an underground industrial landfill. Which compound would you expect to move fastest with groundwater? Which would be easiest to remove by air stripping? Which would be best to remove by adsorption?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
Organic Chemistry
Chemistry
ISBN:9781305580350
Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote
Publisher:Cengage Learning