Week 8

This week in lab, glass and cellulose fibers were cut into 10 in squares to prepare for building the composite. The resin, which optimized the desired properties, contained 15% styrene and 15% MFA. Once the resin was prepared and the fibers were cut, tacky tape was used to make a vacuum-sealed apparatus, which is shown in the photo gallery. During the curing process, Styrene began to evaporate creating bubbles in the composite structure, which is predicted to weaken the mechanical properties of the composite. After the composite was removed from the glass slab, it was post cured over night in a 128 degree Celsius oven to finish the curing process. Once curing was complete, a layout containing .5 x 5 x .125 inch samples was drawn onto the composite to cut into bars to follow three point bend testing standards.

Week 7

The results of the previous weeks testing were analyzed by graphing the viscosity and Tg of each sample versus the percent of styrene used(see Results Viscosity vs Tg).  From that optimization graph, we determined that the polymer with the best properties with the least amount of styrene was the sample with 15% styrene and 15% MFA.  That sample had a viscosity that was low enough to make the resin workable in the composite manufacturing stage, and it had a Tg that was about 61˚C which is sufficiently high considering room temperature which is 30˚C.  Lab time was scheduled for next week to use the lab to make composites using this 15% styrene and 15% MFA resin with both glass fibers which are an industry standard and Biomid fibers which are made from cellulose.  We also decided to use the resin that had no styrene and 30% MFA in one composite with cellulose fibers in order to make a 100% renewable and styrene free composite.  That resin’s properties of high viscosity and lower Tg were not as good as the samples with styrene, but its properties are good enough that the sample composite made from it would be viable.

Later in this week we also made the first composite with glass fibers and our 15% styrene 15% MFA resin.  We made the sample in 10in by 10in squares of 12 layers of fibers.  The apparatus used to make the composite was a vacuum sealed chamber made of tacky tape and plastic covering.  The vacuum pulled the resin into the chamber, and when the fibers were sufficiently covered in resin the vacuum pump was turned off and the tubes going into the chamber were clamped to keep out any air.

Week 6

This week our group prepared the resin for the curing process. One sample of each resin was tested using the AR2000 viscometer with a concentric cylinder setup.  That type of setup was used over a parallel plate setup because the samples contained styrene which would evaporate off of the parallel plate setup.  The shear rate of the cylinder was increased from 20 to 200 1/s.  That was done to find out if the resin was a newtonian or non-newtonian liquid.  The results showed that the resin was a newtonian liquid. The resin was cured into six sample bars, two of each resin.  The sample bars were used for Dynamic Mechanical Analysis (DMA) testing. A sinusoidal stress was applied and the strain in the material was measured, determining the complex modulus.  The samples were tested under temperatures between -150°C and +150°C, increasing in 10°C increments.  The frequency of the stress was varied. Both the change in temperature and frequency, lead to variations in the complex modulus.  This was the most efficient approach used to locate the glass transition temperature (T_g).

Week 5

This week our group went to the lab to make the modified resin with the help of  Emre Kinaci.  First, the hot water bath was prepared to 90° C.  The four components used to make the modified resin were:  200 g Cardolite NC-514 Epoxy Resin, 0.243 g Hydroquinone (inhibitor), 2.43 g AMC-2 (catalyst), and 43.03 g Methacrylic Acid. The components were combined in a boiling flask.  The flask was submerged in the hot water bath, starting the reaction.  The reaction proceeded for four hours.  GPC and FTIR testing were conducted on samples of the mixture before and after the reaction.  These tests showed the change in chemical structure, as expected.  The FTIR results showed the removal of the epoxy peak around 918 cm-1 and the methacrylate peak around 945 cm-1 remained as it was. The modified resin will give the composite stronger mechanical properties.

Week 4

During lab this week, Ph.D. Candidate, Emre Kinaci, gave a presentation on his previous work with cashew nut shell oil. In this presentation, he discussed his testing and results along with what our group needed to know to move forward. The on hand materials were discussed, and they include:

•                NC547- 3 epoxy functional groups.
•                DGEBA - A polymer resin.
•                NC514 -  A 2 epoxy functional groups.
•                Lite 2513- A 1 epoxy functional group.
•                Lauric Acid- A 12-Carbon saturated fatty acid chain.
•                Styrene- A common and effective petrochemical  that decreases viscosity and increases modoulous properties.
•                Methacrylated Fatty Acid- An effective fatty acid chain that proved effective in polymer testing.

In Kinaci's previous work, a ratio of 70/30 from cashew nut oil to styrene had the best results for the amount of styrene present. The industrial limit is 25% styrene in any given polymer, because it is carcinogenic. This result was used  build a template for testing our resin. It was decided that the 30% styrene would be split into various percentages of styrene and MFA to increase the renewability of the resin. After testing, the resin with the best properties and renewability will be used to test Cellulose and Glass fibers in a composite structure. A meeting was arranged for the experiment to be conducted in Week 5.

Week 3

This week, a meeting was held with Dr. Palmese to discuss the progress and eventual outcomes of the project. Some of the topics discussed included:
- Epoxy polymerization with amine curing agents
- Free Radical Polymerization
- Use of MFAs instead of styrene
- Cashew nut shell oil derivatives such cardol and anacardic acid
- Bio-oil formation from pyrolysis
Further analysis of these topics can be found in the background information section of this blog.

In addition, it was outlined what needs to be acquired to actually conducted to project; the curing agent LITE 2562, natural fiber meshes and cashew nut shell oil derivatives. Once these products are acquired, lab times can be set up, and the procedure can be carried out.

Week 2

This week in lab, a visit was made to the Chemical Engineering Lab in Bossone 521. Graduate students who conduct research in the lab proctored a tour for the group. An introduction to the test materials, as well as the beginning chemistry was given. In addition, machines that will be used to test the polymer were introduced, including the Differential Scanning Calorimeter, the Charpy machine, and the IZOD machine.

After touring the lab, the initial design proposal was made. It was outlined that tests were to be conducted on a polymer constructed from cashew nut oil to test its qualities, such as hardness, durability, and light weightiness. It was deciding that project would be split into five distinct steps; the initial 2 weeks will be spent on Literature study and gathering background knowledge.  The next three weeks will be spent on testing the Epoxy Resin. The following three weeks will be spent on Composite setting. The final three weeks will be spent developing the final deliverable and drafting the final report.