Polymer Lab
Abstract: This lab was designed in order to construct and compare polymers with different lengths of chains. Different chain lengths were created using different predetermined amounts of the catalyst. The liquid polymers were poured into two different types of molds prior to being tested, rods and pucks.
Introduction:
Polymers consist of long chains of molecules which are the combination called monomers. “Poly” means many and “mer” means parts. Monomers are the individual units that covalently bond to make polymer chains. Polymers are the combination of many monomers. Polymers are held together by intermolecular forces. Because these forces are weak, it is easy to separate them and they have low melting points. When a polymer consists of one type of monomer it is called a homopolymer and when it consists of multiple types of monomers it is referred to as a copolymer.
The purpose of this lab was to use the polymerization of Caprolactone to analyze how different lengths of polymer chains affected their strength through destructive testing. Two different tests were done on two different shapes of polymer. The first test completed with the rods was the “hang test” and the test with the pucks was the “impact test”.
Methods:
This lab utilized several potentially hazardous chemicals, in order to ensure safety, goggles, aprons, and gloves were worn at all times. All work with chemicals was done within fume hoods. All of the chemicals are harmful if used improperly, inhaled, or ingested. The catalyst and initiator used are irritants and flammable liquids and should always be used with care.
Initially we prepared the molds for the polymers. We created two rod (scoopula) molds, prepped a disk mold (aluminum weighing boat), and planned on using a Santa mold. The objective of this process was to create molds that would shape the polymers prior to them being tested. Any shape of mold would be successful at completing this task. The molds were designed not to leak so that when we poured the liquid polymer in, it would stay in the mold. The purpose of pouring the polymers into molds so that once they hardened we would be able to test their properties. There were seven different ratios of catalyst in polymers labeled A-G. The amount of stannous octoate was predetermined and decreased from A to G. When polymers have a cross-linked microstructure usually are stronger and have higher melting points because there are more bonds between monomers. Longer chains have more intermolecular attraction between molecules and therefore are generally stronger and have higher melting points.
Results:
Groups A-G each used different ratios of catalyst in creating their polymers. Groups C, F, and G did not successfully create any rods and therefore are emitted from this table 1 and are not accounted for in the results for the polymer rods. The rod hang test consisted of separating two tables and hanging weights on the rods until they snapped and recording the weight that was dependent on the rods prior to it breaking. Each rod was creating using the same type of mold and therefore each had the same thickness and similar length.
Table 2: Puck Impact Test
Angle Degree From Drop
The puck impact test was designed to test how changing the length of the polymer changes affected the strength of the polymer. This test utilized the pucks that were taken from the aluminum weighing boat mold. A hammer was dropped on the puck from increasing angles until it broke. Essentially the idea for this test was that the hammer would have to be dropped from a higher angle to be broken.
Discussion: After briefly summarizing the purpose, methods and the results, propose an explanation for trends observed in the results. Think carefully about what higher levels of catalyst and initiator will do to the number and size of polymer molecules and how this in turn might affect the physical properties.
The purpose of this experiment was to create polymers with different chain lengths and then observe how the chain length affects the properties of the polymer such as strength and melting point. Seven different ratios of catalyst were used in creating the polymers. Two tests on the polymers were done, the rod test and the puck test. The results for the pucks was inconclusive and the test for the rods wasn’t extremely compelling.
The puck impact test was inconclusive because there are not any trends within the data. I believe this is because of how the test was designed. I don’t believe the angle under which the puck broke was a good indicator of its strength. Another variable that wasn’t accounted for during the tests was the thickness of the pucks. This factor may have had more of an impact on when the hammer broke the polymer.
Introduction:
Polymers consist of long chains of molecules which are the combination called monomers. “Poly” means many and “mer” means parts. Monomers are the individual units that covalently bond to make polymer chains. Polymers are the combination of many monomers. Polymers are held together by intermolecular forces. Because these forces are weak, it is easy to separate them and they have low melting points. When a polymer consists of one type of monomer it is called a homopolymer and when it consists of multiple types of monomers it is referred to as a copolymer.
The purpose of this lab was to use the polymerization of Caprolactone to analyze how different lengths of polymer chains affected their strength through destructive testing. Two different tests were done on two different shapes of polymer. The first test completed with the rods was the “hang test” and the test with the pucks was the “impact test”.
Methods:
This lab utilized several potentially hazardous chemicals, in order to ensure safety, goggles, aprons, and gloves were worn at all times. All work with chemicals was done within fume hoods. All of the chemicals are harmful if used improperly, inhaled, or ingested. The catalyst and initiator used are irritants and flammable liquids and should always be used with care.
Initially we prepared the molds for the polymers. We created two rod (scoopula) molds, prepped a disk mold (aluminum weighing boat), and planned on using a Santa mold. The objective of this process was to create molds that would shape the polymers prior to them being tested. Any shape of mold would be successful at completing this task. The molds were designed not to leak so that when we poured the liquid polymer in, it would stay in the mold. The purpose of pouring the polymers into molds so that once they hardened we would be able to test their properties. There were seven different ratios of catalyst in polymers labeled A-G. The amount of stannous octoate was predetermined and decreased from A to G. When polymers have a cross-linked microstructure usually are stronger and have higher melting points because there are more bonds between monomers. Longer chains have more intermolecular attraction between molecules and therefore are generally stronger and have higher melting points.
Results:
Groups A-G each used different ratios of catalyst in creating their polymers. Groups C, F, and G did not successfully create any rods and therefore are emitted from this table 1 and are not accounted for in the results for the polymer rods. The rod hang test consisted of separating two tables and hanging weights on the rods until they snapped and recording the weight that was dependent on the rods prior to it breaking. Each rod was creating using the same type of mold and therefore each had the same thickness and similar length.
Table 2: Puck Impact Test
Angle Degree From Drop
The puck impact test was designed to test how changing the length of the polymer changes affected the strength of the polymer. This test utilized the pucks that were taken from the aluminum weighing boat mold. A hammer was dropped on the puck from increasing angles until it broke. Essentially the idea for this test was that the hammer would have to be dropped from a higher angle to be broken.
Discussion: After briefly summarizing the purpose, methods and the results, propose an explanation for trends observed in the results. Think carefully about what higher levels of catalyst and initiator will do to the number and size of polymer molecules and how this in turn might affect the physical properties.
The purpose of this experiment was to create polymers with different chain lengths and then observe how the chain length affects the properties of the polymer such as strength and melting point. Seven different ratios of catalyst were used in creating the polymers. Two tests on the polymers were done, the rod test and the puck test. The results for the pucks was inconclusive and the test for the rods wasn’t extremely compelling.
The puck impact test was inconclusive because there are not any trends within the data. I believe this is because of how the test was designed. I don’t believe the angle under which the puck broke was a good indicator of its strength. Another variable that wasn’t accounted for during the tests was the thickness of the pucks. This factor may have had more of an impact on when the hammer broke the polymer.
Spectroscopic Investigation of Metals in Solution
Introduction-
The purposes of this lab were to understand the Bohr and quantum mechanical models of the atom and to be able to explain how they relate to atomic emission spectrum lines, to become familiar with the use of a spectroscope to analyze several samples, to develop an understanding of the role that emission lines and spectroscopy have played in the refinement of atomic models, and to develop an understanding of the role that emission lines and spectroscopy have played in the discovery of new substances. This lab had three different parts, each with a different objective. The first part was a qualitative investigation included burning melamine foam with a Bunsen burner to view the flame color that different solutions produced. The second part involved using a spectrometer to identify substances based on wavelength and intensity. The third section was the analysis of a spectrum tube with a spectroscope to identify elements.
The Bohr model of the atom shows a small positively charged nucleus at the center of the atom that is orbited by electrons. Within the atom, electrons move to different energy levels, each shift creating different colors. Each time they drop to the first level they create light that is not visible to the human eye. The quantum mechanical model of the atom is very similar to the Bohr model with the exception that the location of the electrons is constantly speculated in a probability cloud with specific energy values. The atom began as theory that it was a small, hard sphere. As time went on and the atom was further understood, the nucleus, electrons, and protons were discovered. Also there is now the understanding of the extreme density of the nucleus.
Atomic emission spectrum lines are the result of photons that are emitted when energized electrons fall back closer to the nucleus. A spectrometer is used to separate the light waves and show the individual spectrum lines. It works by taking in light, breaking it into its spectral components, and then digitizing the signal to show the wave lengths. Spectroscopy is the study and recognition of spectra created by matter. Because each element has a unique set of emission lines, spectroscopy can be used to identify elements as well as discover unknown elements. When a substance includes a set of lines that are unaccounted for, it can be assumed that there is at least one element that is also unaccounted for.
Part 1:
Results
Table 1:
Solution Flame Color NaCl Light yellow orange CuCl2 Bright green LiCl Orange/red/pink KCl Light orange/purple CaCl2 Deep orange (Broncos orange) SrCl2 Burnt reddish orange CaCO3 Light purple with flashes of green and orange Na2CO3 Slightly darker orange than CaCl2 K2SO4 Very light purple/pink with orange CaSO4 Light blue with green and orange Unknown 4 Bright/light orange Unknown 5 Dark red
This table includes the solution that was burned along with the flame color it resulted in.
Solution Flame Color NaCl Light yellow orange CuCl2 Bright green LiCl Orange/red/pink KCl Light orange/purple CaCl2 Deep orange (Broncos orange) SrCl2 Burnt reddish orange CaCO3 Light purple with flashes of green and orange Na2CO3 Slightly darker orange than CaCl2 K2SO4 Very light purple/pink with orange CaSO4 Light blue with green and orange Unknown 4 Bright/light orange Unknown 5 Dark red
Discussion
The purpose of this section of the lab was to identify unknown solutions based on the flame color. The color of the flame is related to the color of the solution. This relationship was first observed when we recognized that both the solution and flame of CuCl2 were green. The color of the solution can help predict the color of the flame although because many of the solutions didn’t have a color, that relationship could not predict the color of the flame. The cations (metals) determine the color of the flame because the heat excites the metal ions, which emit the visible light. Because the ions are unique, they emit different colors. In unknown 4 we suspect Na (Sodium) was present because of the bright orange flame. We are not very confident with this conclusion because we noted multiple orange and yellow flames, making it more difficult to narrow down which elements were present in this unknown. For unknown 5, we assume lithium is present because the flame was a dark red color. Red flame was also present in LiCl which supports this theory. Because many of the flames appeared similar in color, it would be difficult to identify all of the elements using this method. More accuracy could be provided by multiple trials or another method. It is sometimes difficult to use colors in this way because they vary and sometimes are too similar to distinguish.
We concluded that KCl was present in our unknown because of the consistency of the peaks compared to the sample of KCl. The peaks and intensity are consistent therefore indicating they are the same substance. Because each element has a unique set of spectra lines, they also have unique color intensity and therefore unique peaks on an Intensity vs. Wavelength graph. These peaks can be compared to the known peaks expected for each element and used to identify elements. The peaks on Intensity vs. Wavelength graphs are the same colors are the lines that would show up using a spectrometer. Each peak would match an emission line that exists for each element.
Part 3:
Discussion:
By comparing what we observed (see figures 1-3) to the known spectrum lines (see figures 4-6 below) we were able to identify the elements in each spectrum tube. We classified unknown A as hydrogen after viewing the visible spectrum. We noted three very distinct lines, one dark blue/violet (~410nm), one light blue(~455nm), and one dark red(~690nm). When we compared it the Atomic Emission Spectra Key, we were able to confidently identify this as hydrogen. The unknown emission spectrum labeled “B” we recorded over seven different spectra lines. A violet line at about 410 nm, multiple blue and blue green lines between 450 and 500, one green line at about 525, multiple yellow/orange lines between 550 and 650, and one red line at about 655. When we compared this spectrum to the key, it was fairly easy to identify this as carbon. The third unknown labeled “C” had five spectrum lines. Three blue-ish lines between 450nm and 500nm, a red line at about 690nm, and an orange line at 590nm. Because each element possesses a unique visible spectrum, spectroscopy can be used to identify elements. Spectroscopy was used to prove the existence of a previously unknown element named Cesium. In the 1860s cesium was discovered through the examination of a mixture with a spectrometer. The other known elements the mixture consisted of all had recorded visible spectrums and through their separation and removal, cesium was the only remaining component of the mixture. When the spectrum lines of cesium were unexpectedly seen, scientists were able to determine its existence.
Figure 4
Hydrogen: Unknown A
Figure 5
Carbon: Unknown B
Figure 6
Lithium: Unknown C
The purposes of this lab were to understand the Bohr and quantum mechanical models of the atom and to be able to explain how they relate to atomic emission spectrum lines, to become familiar with the use of a spectroscope to analyze several samples, to develop an understanding of the role that emission lines and spectroscopy have played in the refinement of atomic models, and to develop an understanding of the role that emission lines and spectroscopy have played in the discovery of new substances. This lab had three different parts, each with a different objective. The first part was a qualitative investigation included burning melamine foam with a Bunsen burner to view the flame color that different solutions produced. The second part involved using a spectrometer to identify substances based on wavelength and intensity. The third section was the analysis of a spectrum tube with a spectroscope to identify elements.
The Bohr model of the atom shows a small positively charged nucleus at the center of the atom that is orbited by electrons. Within the atom, electrons move to different energy levels, each shift creating different colors. Each time they drop to the first level they create light that is not visible to the human eye. The quantum mechanical model of the atom is very similar to the Bohr model with the exception that the location of the electrons is constantly speculated in a probability cloud with specific energy values. The atom began as theory that it was a small, hard sphere. As time went on and the atom was further understood, the nucleus, electrons, and protons were discovered. Also there is now the understanding of the extreme density of the nucleus.
Atomic emission spectrum lines are the result of photons that are emitted when energized electrons fall back closer to the nucleus. A spectrometer is used to separate the light waves and show the individual spectrum lines. It works by taking in light, breaking it into its spectral components, and then digitizing the signal to show the wave lengths. Spectroscopy is the study and recognition of spectra created by matter. Because each element has a unique set of emission lines, spectroscopy can be used to identify elements as well as discover unknown elements. When a substance includes a set of lines that are unaccounted for, it can be assumed that there is at least one element that is also unaccounted for.
Part 1:
Results
Table 1:
Solution Flame Color NaCl Light yellow orange CuCl2 Bright green LiCl Orange/red/pink KCl Light orange/purple CaCl2 Deep orange (Broncos orange) SrCl2 Burnt reddish orange CaCO3 Light purple with flashes of green and orange Na2CO3 Slightly darker orange than CaCl2 K2SO4 Very light purple/pink with orange CaSO4 Light blue with green and orange Unknown 4 Bright/light orange Unknown 5 Dark red
This table includes the solution that was burned along with the flame color it resulted in.
Solution Flame Color NaCl Light yellow orange CuCl2 Bright green LiCl Orange/red/pink KCl Light orange/purple CaCl2 Deep orange (Broncos orange) SrCl2 Burnt reddish orange CaCO3 Light purple with flashes of green and orange Na2CO3 Slightly darker orange than CaCl2 K2SO4 Very light purple/pink with orange CaSO4 Light blue with green and orange Unknown 4 Bright/light orange Unknown 5 Dark red
Discussion
The purpose of this section of the lab was to identify unknown solutions based on the flame color. The color of the flame is related to the color of the solution. This relationship was first observed when we recognized that both the solution and flame of CuCl2 were green. The color of the solution can help predict the color of the flame although because many of the solutions didn’t have a color, that relationship could not predict the color of the flame. The cations (metals) determine the color of the flame because the heat excites the metal ions, which emit the visible light. Because the ions are unique, they emit different colors. In unknown 4 we suspect Na (Sodium) was present because of the bright orange flame. We are not very confident with this conclusion because we noted multiple orange and yellow flames, making it more difficult to narrow down which elements were present in this unknown. For unknown 5, we assume lithium is present because the flame was a dark red color. Red flame was also present in LiCl which supports this theory. Because many of the flames appeared similar in color, it would be difficult to identify all of the elements using this method. More accuracy could be provided by multiple trials or another method. It is sometimes difficult to use colors in this way because they vary and sometimes are too similar to distinguish.
We concluded that KCl was present in our unknown because of the consistency of the peaks compared to the sample of KCl. The peaks and intensity are consistent therefore indicating they are the same substance. Because each element has a unique set of spectra lines, they also have unique color intensity and therefore unique peaks on an Intensity vs. Wavelength graph. These peaks can be compared to the known peaks expected for each element and used to identify elements. The peaks on Intensity vs. Wavelength graphs are the same colors are the lines that would show up using a spectrometer. Each peak would match an emission line that exists for each element.
Part 3:
Discussion:
By comparing what we observed (see figures 1-3) to the known spectrum lines (see figures 4-6 below) we were able to identify the elements in each spectrum tube. We classified unknown A as hydrogen after viewing the visible spectrum. We noted three very distinct lines, one dark blue/violet (~410nm), one light blue(~455nm), and one dark red(~690nm). When we compared it the Atomic Emission Spectra Key, we were able to confidently identify this as hydrogen. The unknown emission spectrum labeled “B” we recorded over seven different spectra lines. A violet line at about 410 nm, multiple blue and blue green lines between 450 and 500, one green line at about 525, multiple yellow/orange lines between 550 and 650, and one red line at about 655. When we compared this spectrum to the key, it was fairly easy to identify this as carbon. The third unknown labeled “C” had five spectrum lines. Three blue-ish lines between 450nm and 500nm, a red line at about 690nm, and an orange line at 590nm. Because each element possesses a unique visible spectrum, spectroscopy can be used to identify elements. Spectroscopy was used to prove the existence of a previously unknown element named Cesium. In the 1860s cesium was discovered through the examination of a mixture with a spectrometer. The other known elements the mixture consisted of all had recorded visible spectrums and through their separation and removal, cesium was the only remaining component of the mixture. When the spectrum lines of cesium were unexpectedly seen, scientists were able to determine its existence.
Figure 4
Hydrogen: Unknown A
Figure 5
Carbon: Unknown B
Figure 6
Lithium: Unknown C
Density Lab (Methods and Results)
Methods and Materials-
The density of carbon dioxide was found through measurements of mass and volume. Initially, to obtain carbon dioxide, we submerged a test tube which was filled with water upside down in a 1000ml beaker that was completely filled with water. Because this lab did not pose extreme safety threats, lab goggles were the only precautionary measure taken. At first, we created the reaction in a 250 ml Erlenmeyer flask and used a rubber stopper and rubber tube that failed at directing the carbon dioxide into another container where we would then measure the mass and volume. However, almost immediately after beginning the first trial, it was clear that this method of obtaining CO2 would not be successful because it is denser than air and wouldn’t rise up into the tubing. After reconstructing the lab procedure, we decided to use water because it has a higher density that could be used to help achieve the data required. We found the mass of the test tube and rubber topper using a scale and filled the beaker with water to record what the volume of the CO2. Upon filling both a 1000ml beaker and small test tube with water, we turned the test tube upside down and placed it in the water so that there was no air in it. An effervescent tablet was dropped in and the tube was positioned with the goal of catch the CO2 bubbles and displacing the water, leaving us with a test tube that only contained carbon dioxide. This process was continued until the CO2 had completely replaced the water that had been in the test tube. We subtracted the final mass of the test tube from the initial mass of the test tube to find the mass of the carbon dioxide gas. The test tube could hold 13.5ml and because the gas completely filled it, we knew the carbon dioxide gas had a volume of 13.5ml. We divided the mass by the volume to get the density.
Results-
To find the density of carbon dioxide, we found mass and volume. Three separate attempts were made to fill a test tube with only carbon dioxide. The first and second attempts left both water and carbon dioxide in the test tube. It wasn’t until the third attempt, that the carbon dioxide filled all 13.5ml of the test tube. We used the equation mass/volume=density to find our results. Carbon dioxide has an accepted density of 1.98 kg/m³. As seen in Table 1, we conducted three trials to determine density. The third was the most accurate because we made the mistake of not removing all of the water before finding the mass of the carbon dioxide.
The density of carbon dioxide was found through measurements of mass and volume. Initially, to obtain carbon dioxide, we submerged a test tube which was filled with water upside down in a 1000ml beaker that was completely filled with water. Because this lab did not pose extreme safety threats, lab goggles were the only precautionary measure taken. At first, we created the reaction in a 250 ml Erlenmeyer flask and used a rubber stopper and rubber tube that failed at directing the carbon dioxide into another container where we would then measure the mass and volume. However, almost immediately after beginning the first trial, it was clear that this method of obtaining CO2 would not be successful because it is denser than air and wouldn’t rise up into the tubing. After reconstructing the lab procedure, we decided to use water because it has a higher density that could be used to help achieve the data required. We found the mass of the test tube and rubber topper using a scale and filled the beaker with water to record what the volume of the CO2. Upon filling both a 1000ml beaker and small test tube with water, we turned the test tube upside down and placed it in the water so that there was no air in it. An effervescent tablet was dropped in and the tube was positioned with the goal of catch the CO2 bubbles and displacing the water, leaving us with a test tube that only contained carbon dioxide. This process was continued until the CO2 had completely replaced the water that had been in the test tube. We subtracted the final mass of the test tube from the initial mass of the test tube to find the mass of the carbon dioxide gas. The test tube could hold 13.5ml and because the gas completely filled it, we knew the carbon dioxide gas had a volume of 13.5ml. We divided the mass by the volume to get the density.
Results-
To find the density of carbon dioxide, we found mass and volume. Three separate attempts were made to fill a test tube with only carbon dioxide. The first and second attempts left both water and carbon dioxide in the test tube. It wasn’t until the third attempt, that the carbon dioxide filled all 13.5ml of the test tube. We used the equation mass/volume=density to find our results. Carbon dioxide has an accepted density of 1.98 kg/m³. As seen in Table 1, we conducted three trials to determine density. The third was the most accurate because we made the mistake of not removing all of the water before finding the mass of the carbon dioxide.