Experiment 1 - Nylon Interfacial Polymerization | PSC 341, Lab Reports of Chemistry

Download Experiment 1 - Nylon Interfacial Polymerization | PSC 341 and more Lab Reports Chemistry in PDF only on Docsity! Drs. D.A.Savin, D.L. Patton Polymer Techniques PSC341L/720 Electronic Handout 2008 D.A.Savin Experiment 1: Nylon Interfacial Polymerization Condensation Polymerization Polymerization reactions may be broadly classified as step-growth and chain-growth reactions. In step-growth reactions, polymer chains grow in a slow, step-wise manner; while in chain- growth reactions polymer chains grow rapidly to high molecular weight. Condensation and some ring-opening polymerizations are examples of step-growth reactions. Free radical and UV- initiated polymerizations are examples of chain-growth reactions. You will prepare polymers by each of these techniques in the laboratory this fall. In step-growth polymerizations, any two species can react together: monomer + monomer
dimer monomer + dimer
trimer dimer + dimer
tetramer dimer + trimer
pentamer monomer + trimer
tetramer etc. Thus, reaction mixtures are characterized by a wide distribution of molecular species. Monomer disappears early in the reaction, there is slow build of molecular weight, and high molecular weight polymer typically appears only at long reaction times. Drs. D.A.Savin, D.L. Patton Polymer Techniques PSC341L/720 Electronic Handout 2008 D.A.Savin Condensation polymerization reactions involve the loss of a small molecule, such as water. The following are some examples of reactions to afford common step-growth polymers: Polyamide: H2N R NH2 HO R' O O OH N H R N H O R' O + H2O + Examples of polyamides: R = R' = Kevlar (tm) R = (CH2)6 R' = (CH2)4 Nylon 6-6 Polyurethane: HO R OH R N H + H2O + O R' OCN R' NCO O N H O O Drs. D.A.Savin, D.L. Patton Polymer Techniques PSC341L/720 Electronic Handout 2008 D.A.Savin Interfacial Polymerization In interfacial polymerization, reaction proceeds at the interface of two immiscible liquid phases. Each phase contains one monomer. In our experiment, the acid chloride resides in the organic phase and the diamine in the aqueous phase. Polymerization rate is controlled by the rate of diffusion of reactants to the interface. In contrast to bulk condensation polymerization, in interfacial polymerization high molecular weights are achieved rapidly. High molecular weights are produced at room temperature, and strict control of stoichiometry of reactants is not required. Polycarbonate is an example of a commercial polymer that is commonly produced via interfacial polymerization. Study Questions 1. What would be the effect of adding a monofunctional monomer to the reaction mixture? 2. Describe the differences in properties for Nylon 6-6 vs Nylon 6-10. 3. What are some disadvantages of interfacial polymerization in comparison to bulk polymerization? 4. What is the effect of equilibrium constant (Keq) on molecular weight in condensation polymerization. Drs. D.A.Savin, D.L. Patton Polymer Techniques PSC341L/720 Electronic Handout 2008 D.A.Savin Appendix A: Some Tradenames and Producers of Nylon 6 and Nylon 66 Type Polyamides 2 Tradename Producer Ultramid  BASF Capron  Durethan  LANXESS (Spin-off from Bayer) VYDYNE  Solutia (Originally Monsanto) Aegis  Capran  Honeywell (some in trade from BASF) Akulon  DSM Engineering Polymers Zytel  DuPont Polynil  Nilit Technyl Rhodia Appendix B: 2000 Global Consumption of Polyamides, Thousands of Tons Total Nylon Fiber 3 4000 Engineering Thermoplastics 4 1800 Nonwoven Fibers 5 50 Appendix C: Properties of Common Aliphatic Nylons 6 Property Nylon 6-6 Nylon 6 Nylon 6-10 HDT (heat deflection temp) / o C 75 80 80 Melting point / o C 265 215 220 Tensile Strength /kPa 82,750 62,000 55,000 Drs. D.A.Savin, D.L. Patton Polymer Techniques PSC341L/720 Electronic Handout 2008 D.A.Savin References: General References 7,8,9,10 1 Ram, Arie “Fundamentals of Polymer Engineering” Plenum Press: New York, 1997. 2 http://www.ides.com/generics/Nylon/Nylon_products.htm 3 http://www.plasticsnews.com/subscriber/fyi.html?id=1060185162 4 http://pardos.marketing.free.fr/37.htm 5 http://www.engr.utk.edu/mse/pages/Textiles/Nylon%20fibers.htm 6 Seymour, R. B. “Polymers for Engineering Applications” ASM International, 1987. 7 Allcock, H. R.; Lampe, R. W.; Mark, J. E. “Contemporary Polymer Chemistry”, Ed. 3, Pearson Education: Upper Saddle River, NJ, 2003. 8 http://www.matweb.com/reference/nylonmfr.asp 9 http://www.pbs.org/wgbh/aso/databank/entries/btcaro.html 10 http://www.invista.com/