Wednesday, June 5, 2019

Synthesis and Characterization of Nylon-6,6 Polymer

Synthesis and Characterization of Nylon-6,6 PolymerAbstractSynthesis and characterization of nylon-6,6 polymer was performed in this try out. Nylon-6,6, was obtained from adipoyl chloride and 1,6-hexanediamine monomers, dissolved in cyclohexane and water. Employing interfacial polymerization technique, thin film of nylon proceeds was formed and collected. The final mathematical product were white peaces of small fragile strings with a total lot of 0.0694 g and 4 cm in length. Infrargond spectroscopy then characterized the final product and confirmed successeful synthesis of nylon-6,6 polymer due to the port of N-H thining, C=O stretching, and N-H bending from the substitute(prenominal) amide group and from the nylon polymer.IntroductionPolymers are macromolecules consisting of smaller subunits, called monomers.4 There are two main types of synthetic polymers, according to the chemical mechanism by which they are synthetically made step- growth and chain-growth polymers.4 One of the most popular synthetic polymers is nylon-6,6 due to low cost and ease of synthesis. There is no human activity where plastics are not used on a daily basis. Nylon in particular is widely used, due to variety of properties such as elasticity, flexibility, lightweight and strength.5 Clothing, electronics, packaging, cars, airplanes, medical supplies, cookware, ropes all examples of nylon fabrics.5In this experiment nylon is made by step- growth polymerization and condensation reaction. The monomers involved in this polymerization reaction are adipoyl chloride and 1,6-hexanediamine dissolved in cyclohexane, respectively. The chloride from the acid and the hydrogen proton from the amine group form a hydrochloric acid.4 The rest of the adipoyl chloride and hexanediamine entrust link together to form a bigger polymer molecule. In each end of this polymer is a primary amine group in one end or an acid chloride group in the opposite end.4 These groups can act in a similar way with other acid/amine groups from the adipoyl chloride and hexanediamine. If many steps of this process are repeated, nylon-6,6 polymer will be formed.4 Hydrochloric acid is generated as a byproduct upon nylon formation, therefore a strong base must be added to neutralize the acidity of HCl, and maintain the pH of the solution. In this experiment sodium hydroxide was used as base.Infrared (IR) spectroscopy will be applied as method of characterization. It will provide development regarding functional groups present in a molecule because the location of the absorption peaks ascertained have been associated with specific types of chemical bonds.6 It could be determine which functional groups from the outset monomers, are present in the nylon spectrum.Results hold over 1 Nylon-6,6 PolymerMass of nylon-6,60.0694 gLength4 cmAppearanceWhite fragile stringsTable 2 IR spectrum of adipoyl chlorideFunctional GroupMolecular MotionObserved Wavenumber (cm-1)Literature determine Range(cm-1)Peak in tensivenessPeak Shape AlkaneC-H adulterate2952.443000-2850WeakBroad acyl chlorideC=O Stretch1779.801820-1780Weak aggressivelyAlkaneC-H in plane bend1404.561480-1350 fairSharpAcyl chlorideC-Cl Stretch681.43800-600StrongSharpTable 3 IR spectrum of 1,6- hexanediamineFunctional GroupMolecular MotionObserved Wavenumber (cm-1)Literature Value Range(cm-1)Peak IntensityPeak Shape1 amineN-H Stretch3323.783300-3250MediumSharpAlkaneC-H Assym. Stretch2921.173000-2850StrongSharpAlkaneC-H Sym. Stretch2846.913000-2850StrongSharp1 amineN-H Bend1603.911640-1530MediumSharpTable 4 IR spectrum of nylon-6,6 polymerFunctional GroupMolecular MotionObserved Wavenumber (cm-1)Literature Value Range(cm-1)Peak IntensityPeak Shape2 amideN-H Stretch3299.03300-3250StrongSharpAlkaneC-H Assym. Stretch2932.03000-2850MediumSharpAlkaneC-H Sym. Stretch2859.03000-2850MediumSharp2 amideC=O Stretch1636.01680-1640 StrongSharp2 amideN-H Bend1538.01560-1530MediumSharpDiscussionIn this experiment, sythesis of nylon-6,6 was c arried out. The final product had an appearance of white pieces of small fragile strings with a total mass of 0.0694 g and 4 cm in length. A way of upward(a) the yield could be different molar ratios of water to solvent changing the solvent. No theorytical yield could be calculated for this reaction because all the polymer chains will have variety of different lengths.1The ability of nylon-6,6 to undergo hydrogen bonding results in high molecular order and high degree of interchain interaction as shown below2 (Figure 1). Each single chain of nylon fiber will interact with the adjacent one, forming a hydrogen bond between the nitrogen proton of the secondary amide and the lone pairs of the type O on the carbonyl, gum olibanum making the nylon polymers strong, difficult to separate and resistant to outside reaction.2The signals for the IR spectrum of adipoyl chloride, are presented in Table 2. The spectrum shows the characteristic weak and narrow paraffin wax peak, C-H stretch at 29 52.44 cm-1. This measure out was within the range 3000-2850 cm-1 for the secondary paraffin series functional groups. The weak and sharp C=O stretch appeared at 1779.80 cm-1 thus correlating with the literary works value 1820-1780 cm-1. A C-H bend for alkanes should appear at 1480-1350 cm-1, which did appear at 1404.56 cm-1 as a medium and sharp peak. A C-Cl stretch was observed at 681.43 cm-1, within the expected range of 800-600 cm-1. This peak appeared weak to strong and sharp.The IR spectrum for 1,6-hexanediamine exhibits the following stretches N-H stretch N-H bend alkane C-H asymmetric stretch and an alkane C-H symmetric stretch. The primary amine is causing the N-H stretch. The literature value for this stretch is from 3300 to 3250 cm-1, which corresponds to the experimental value of 3323.78 cm-1. The peak strength is medium and the shape is sharp. There is another(prenominal) sharp peak with medium intensity caused by the primary amine as well, which appear to be a N-H b end. The experimental value of 1603.91 cm-1 correlates well with the literature value range of 1640-1530 cm-1. There is C-H asymmetric stretch observed at 2921.17 cm-1 and it corresponds to the literature value range of 3000-2850 cm-1, caused by the alkane. It exhibited strong intensity. The C-H symmetric stretch travel in the appropriate range of literature values 3000-2850 cm-1 and it is caused by the alkane as well (See table 3).Analysis of IR spectrum of nylon-6,6 polymer showed successful synthesis. There were quint distinct peaks associated with this compound include the following N-H stretch C=O stretch C-H symmetric stretch C-H antisymmetric stretch and N-H bend. The N-H stretch had an observed peak value of 3300.81 cm-1 and its caused by the secondary amine. It correlates well with the literature values of 3300-3250 cm-1 and with the N-H stretch of 1,6-hexadiamine at 3323.78 cm-1. The two peaks have the same shapes, just slightly different intensities. Nylon-6,6 has stron g intensity whereas the 1,6- hexanediamine, medium one. The C=O stretch had an observed peak value of 1634.04 cm-1. It falls within the expected literature values for this peak 1300-1100 cm-1. It appears at demoralise wavelength, compared to the adipoyl chloride. The proximity of the carbonyl to the nitrogen, lowers the energy of that stretch, due to interchain molecular interactions3. The alkane C-H assymetric and symmetric stretches evident at 2932 cm-1 and 2832 cm-1 are nearly identical with the C-H stretches of 1,6- hexanediamine (See Tables 2 and 3). Differing only in their intensities- medium for the nylon and strong for the 1,6- hexanediamine. All of the observed values fall within their literature range. The N-H bend at 1538 cm-1 with medium intensity and sharp peak, is caused by the secondary amide. It is in the accepted literature data of 1560-1530 cm-1.The study peak not present in the nylon-6,6 spectrum and evident in the starting material spectra for adipoyl chloride is the C-Cl stretch. The acyl chloride stretch is missing because there is no chlorine in the nylon composition, thus explaining why there are no observed stretches below 1000 cm-1. The other major difference is the N-H stretch observed at 3323.78 cm-1 in the hexanediamine spectrum, which appears at lower wavelength and becoming one peak for a secondary amide in the nylon spectrum.ConclusionThis experiment demonstrated successful synthesis of nylon-6,6 polymer. It was accomplished using infrared spectroscopy technique. The IR analysis revealed the appearance of N-H stretching, C=O stretching and N-H bending from a secondary amide group and from the nylon polymer. It showed that there is no C-Cl stretch explaining the absence of chlorine in the nylon polymer as well as the N-H observed on the hexanediamine spectrum, appears on a lower wavelength as a secondary amide in the nylon spectrum. The final product had an appearance of white pieces of small fragile strings with a total mass o f 0.0694 g and 4 cm.However, this experiments allows for multiple errors such as improper pipetting technique improper washing technique incorrect rate of taking out the nylon product from the reaction beaker. A chemical error could be not adding enough sodium hydroxide to neutralize the acidity of HCl, not allowing the reaction to be pushed towards the product.

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