Polymers and Liquid Crystals 1 What kind of reaction will bring about the formation of a polymer from the monomers succinic acid HOOCCH2CH2COOH and ethylenediamine H2NCH2CH2NH2 O C H H C C H H HO A B C D E 2 O H C H H H N C C N H H H OH addition condensation ring opening redox double displacement Below is a piece of a polymer What is the structure of the monomer for this polymer H F H C H A C C F C C C H H F H F F B F C C H H F C F C F F C F C H F C H F H F C H H C H H H F D C F F F E H C F F C C F Supplemental Problems F Chem 112 Spring 2012 1 3 As a polymer becomes more crystalline A B C D E 4 its melting point decreases its density decreases its stiffness decreases its yield stress strength decreases none of the above are correct A polymer that is shaped irreversibly through chemical processes e g cross linking is called A B C D E thermoplastic elastomer thermosetting plastic plasticizer copolymer H H C C H Cl polyvinylchloride H H C C H H n n polyethylene 5 The polyvinylchloride above would form a stiffer polymer than the polyethylene due to the presence of A B C D E Dipole dipole interactions between polymer chains Hydrogen bonding between polymer chains Covalent cross linking between polymer chains Ionic bonding between polymer chains Metallic ions between polymer chains Supplemental Problems Chem 112 Spring 2012 2 6 Which of the following factors determine the physical properties of silicone polymers 1 degree of cross linking 2 length of chain 3 composition of side group A B C D E 1 only 2 only 3 only 1 and 3 only 1 2 and 3 7 Which one of the following is most likely to exhibit liquid crystalline behavior 8 A CH3O C6H4 N N C6H4 CH2CH2CH3 B CH3O C6H4 COOH C CH3O C6H4 CH2CH2CH3 D CH3O CH2CH2 N N CH2CH2CH3 E CH2CH COOCH3 n Which one of the following is likely to be the monomer unit of a polymer synthesized by addition polymerization A HOOC CH2 6COOH B CH3 2SiCl2 C CH3CH CH2 D CH3COOH E CH3CH2CH3 9 Pick the polymer s that are made by addition polymerization reactions 1 Polyethylene A 1 2 and 3 B 1 and 3 C 2 and 3 D 1 only E 3 only Supplemental Problems 2 Polyamide 3 Polyester Chem 112 Spring 2012 3