(a) Hard contact lenses, which first became popular in the 1960s, were made by polymerizing methyl methacrylate [CH2 = C(CH3)CO2CH3] to form poly(methyl methacrylate) (PMMA). Draw the structure of PMMA. (b) More comfortable softer contact lenses introduced in the 1970s were made by polymerizing hydroxyethyl methacrylate [CH2 = C(CH3)CO2CH2CH2OH] to form poly(hydroxyethyl methacrylate) (poly-HEMA). Draw the structure of poly-HEMA. Since neither polymer allows oxygen from the air to pass through to the retina, newer contact lenses that are both comfortable and oxygen-permeable have now been developed.

(a) Hard contact lenses, which first became popular in the 1960s, were made by polymerizing methyl methacrylate [CH2 = C(CH3)CO2CH3] to form poly(methyl methacrylate) (PMMA). Draw the structure of PMMA. (b) More comfortable softer contact lenses introduced in the 1970s were made by polymerizing hydroxyethyl methacrylate [CH2 = C(CH3)CO2CH2CH2OH] to form poly(hydroxyethyl methacrylate) (poly-HEMA). Draw the structure of poly-HEMA. Since neither polymer allows oxygen from the air to pass through to the retina, newer contact lenses that are both comfortable and oxygen-permeable have now been developed.

Introductory Chemistry For Today

8th Edition

ISBN:9781285644561

Author:Seager

Publisher:Seager

Chapter12: Unsaturated Hydrocarbons

Section: Chapter Questions

Problem 12.35E

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Similar questions

(a) Hard contact lenses, which first became popular in the 1960s, were made by polymerizing methyl methacrylate [CH2=C(CH3)CO2CH3] to form poly(methyl methacrylate) (PMMA). Draw the structure of PMMA. (b) More-comfortable softer contact lenses introduced in the 1970s were made by polymerizing hydroxyethyl methacrylate [CH2=C(CH3)CO2CH2CH2OH] to form poly(hydroxyethyl methacrylate) (poly-HEMA). Draw the structure of poly-HEMA. Because neither polymer allows oxygen from the air to pass through to the retina, newer contact lenses that are both comfortable and oxygen-permeable have now been developed.
3. Dacron is the brand name for the polymer that is made from ethane-1,2-diol and benzene-1,4-dicarboxylic acid. (a) What type of polymer is Dacron? (b) When the two monomers combine, what type of reaction do they undergo and what molecule is eliminated? (c) What is the name for the linkages that join the monomers together?(d) Draw the monomers and the polymer of the reaction to create Dacron. (Use a condensed structural formula in your answer.) HC-C styrene H-O-C- ethane-1,2-diol I H OH НО. 206 H -C-0-H H benzene-1.4-dicarboxylic acid.
(a) Hard contact lenses, which first became popular in the 1960s, were made by polymerizing methyl methacrylate [CH; =C(CH,)CO,CH3] to form poly(methyl methacrylate) (PMMA). Draw the structure of PMMA. (b) More comfortable softer contact lenses introduced in the 1970s were made by polymerizing hydroxyethyl methacrylate [CH2=C{CH)CO,CH,CH2OH] to form poly(hydroxyethyl methacrylate) (poly-HEMA). Draw the structure of poly-HEMA. Since neither polymer allows oxygen from the air to pass through to the retina, newer contact lenses that are both comfortable and oxygen-permeable have now been developed.
A polymer closely related to PET is PBT, which is made from terephthalic acid and butane-1,4-diol.(a) Propose a structure for PBT and write the condensed formula for the structure.(b) What does PBT stand for? That is, what do you expect the trivial name of PBT to be?(c) Would you expect PBT to have a higher or lower melting point than PET? Justify your answer.(d) PBT, rather than PET, is used in molding because it crystallizes faster. Explain why PBT crystallizes more quickly than PET.
Poly(lactic acid) (PLA) has received much recent attention because the lactic acid monomer [CH3CH(OH)COOH] from which it is made can be obtained from carbohydrates rather than petroleum. This makes PLA a more “environmentally friendly” polyester. (A more in-depth discussion of green polymer synthesis is presented in Chapter 30.) Draw the structure of PLA.
(a) Draw the structure of polystyrene, which is formed by polymerizing the monomer styrene, C6H5CH=CH2. (b) What monomer is used to form poly(vinyl acetate), a polymer used in paints and adhesives?
(a) What is the empirical formula of cellulose? (b) Whatis the monomer that forms the basis of the cellulose polymer?(c) What bond connects the monomer units in cellulose:amide, acid, ether, ester, or alcohol?
Poly(lactic acid) (PLA) has received much recent attention because the lactic acid monomer [CH3CH(OH)COOH] from which it is made can be obtained from carbohydrates rather than petroleum. This makes PLA a more “environmentally friendly” polyester. (A further discussion of green polymer synthesis is presented in Chapter 28.) Draw the structure of PLA.
Explain why styrene (CH2=CHPh) can be polymerized to polystyrene by all three methods of chain-growth polymerization.
Can you explain condensation polymerization and give an example with structure of one with 2 carboxylic acid groups and 2 OH groups.
(a) Describe the polymerization of a blend of maleic anhydride and 2-methyl-1,3- propanediol in the presence of an acid catalyst. Draw a chemical reaction scheme showing the intermediate and final products that are formed. Describe the reaction conditions that you would use to maximize the yield of polymer. (b) Draw the structure of the polymer, showing the repeat unit and end groups, that is obtained when the mole ratio of maleic anhydride to diol is 0.95 (c) What is the number average molecular weight of the polymer of Part (b) when the extent of reaction of maleic anhydride is (i) 90% and (ii) 100%. (d) Describe how the structure of the polymer is altered when it is further reacted with styrene in the presence of peroxide.
Poly(vinyl alcohol), PVA, is produced from poly(vinyl acetate) by converting the acetate groups into hydroxyl groups (Section 26.6a.1). As the number of hydroxyl groups in PVA increases, the solubility of the polymer in water decreases. How do you explain this behavior?