Determination Of Polyethylene Lab Report

Chemical interference is relatively low due to the use of chemical modifiers to stabilize the analyte and make the matrix more volatile; hence, it contributes in further improvement to the sensitivity of this technique. However, the technique has some disadvantages like:- (1) limited working range, (2) slow analysis, and (3) high cost (Harvey, D. 2010).

What is its melting point? 1,405 K: 1,132 C: 2,070 F. boiling point? 4,404 K: 4,131 C: 7,468 F

First, we need to plug in the variables into the numbers from the information to create our first equation for the system. 3j (glasses of orange juice) + 5p (5 pancakes) = 7.60. Now, plug in the variables into the numbers from the information for the second equation for the system. j ( a glass of orange juice) + 2p ( 2 pancakes) = 2.90.

Calibration tells you if the instrument is accurate or not. Based on that knowledge, you can adjust it to get a more accurate reading.

With time (t) on the x-axis and temperature (Celsius) on the y-axis, the exponential change could be easily observed. At the beginning of the laboratory the masses of the combined polypropylene test tube and 100 mL beaker were recorded by a digital electronic scale. A dry polypropylene test tube was obtained and approximately 2 mL of p-xylene was squirted into it with the use of a pipette. This was added to the beaker and weighed. 10 drops of toluene was then added and weighed again. The polypropylene test tube, which now contained 10 mL of p-xylene and 10 drops toluene was removed from the beaker and placed into a replica 100 mL beaker which was halfway filled with an ice water mixture. The temperature sensor, which was connected to the microlab application was placed inside of the polypropylene test tube and stirred rapidly around the outskirts of the bottom of the polypropylene test tube. The mixture began freezing, giving off an icy slush complex. Once the temperature appeared to have reached the nucleation point and leveled out at its freezing point, the application was stopped. This value was recorded in the laboratory manual. The temperature sensor was rinsed off then wiped, the beaker was re-filled with ice, and the test tube was put into the test tube rack to be thawed. Once thawed, this was discarded into the waste bin

The absorbance is measured using a Plate reader and a Standard curve is generated. Also, the different types of pipetting techniques are assessed in this Assay.

Upon heating, both began to discolor into a darker liquid and produced small flames near the top of the test tube when rapidly boiled. During the heating process, both reactions appeared very similar. Both were very viscous and black in color. Once cooled, however, both produced very different polyesters. The ethylene glycol was black, matte, and opaque with a brittle surface. There was little to no flexibility and elasticity in the final product. The glycerol was a slightly translucent, black in color, and had a smooth shiny surface. It had a little more elasticity and flexibility compared to the ethylene glycol. Additionally, Nylon 6,6 was synthesized and drawn into long fibers. The fibers went from a semi-translucent material when drawing to a solid white fiber once dried. A total fiber length of 13.058 ft was

1) Adding sodium carbonate was the step in the reaction that prevented the extraction of acidic organic impurities from the tea solution. The carbonate ion reacts with acidic compounds to form H2CO3, it’s conjugate acid. The carbonic acid (H2CO3) can then go on to form carbon dioxide and water. 2) A - If you did not use sodium carbonate to remove the organic impurities, then this would have a positive systematic error affect on the final mass of the collected caffeine. This means that adding sodium carbonate prevents the extraction of these impurities, which would decrease the final collected mass and its acidic components.

Incorporation of assay controls included setting up a spectrophotomer and running the chart recorder with a full-scale deflection before the start of the assay. The set recorder had a corresponding value of 1 for the change in the absorbance. Therefore, prior testing was done to observe whether a change occurred in the readings. This helped to indicate that the results were valid, as they could have been affected by a fault during the setting up of the spectrophotometer. On the other hand this was considered as one of the controls for the experiment. Nevertheless, a new cuvette had to be used for each assay.

The PCL molar mass of 80,000 g/mol (Sigma Aldrich). The poly(rotaxane) is an experimental polymer supplied by UBE (No A1000), molecular weight 496000 g/mol and hydroxyl index of 71 mg KOH/g. Chloroform (Merck, Germany) and acetone (Synth-Brazil) were mixed in different proportions by weight without any treatment or purification. All solutions were stirred for 2 hours (New Ethics Shaker, Model 114) at 23° C and electrospun the same day of preparation of the same (thereof). All solutions were prepared in the same order, being added chloroform in acetone, then PCL and subsequently the poly (rotaxane).

The optimized Rose bengal strip and Bromophenol red strip produced curves with better linearity and better curve fit (R) than previous optimized Bromophenol blue (BPB) indicator strip. R-squared values of these two standard curves were 0.847 and 0.870, respectively. Good linearity of the standard curve is important for providing accurate calculation of a given analyte.

In this experiment, solutions of 2-naphthol will be prepared in buffer solutions with pH values near the expected pKa (refer to Table 7.1 in the lab Manual) at 25 °C and the UV-visble spectra of each solution will be measured using a Cary 50 spectrometer. For detailed procedure, refer to the lab manual (J. F. Wójcik and T. S. Ahmadi, Experimental Physical Chemistry, 2015; p.3-5.). A modification of the procedure is, time drift of the pH was not calculated. The pH of the pH = 4.00 buffer was not measured every 45 minutes to 1 hour.

Polymer samples were labeled and radiograph images were taken using a infinity XMA HF-30AP, set to Manual technique mode with an exposure time of 0.016 seconds and MAS@6.1 and 70KV. Images were taken of each sample individually and s-values, numeric value of exposure received by the receptors in the digital system, were recorded 7. For analysis the s-value for the 0% BaSO4 sample was used as a base and subtracted from all the other values to normalize the

To calculate the expected number of pipette tips needed per month take the number of pipette tip per sample to multiply it with the average sample analysed per month, 5 x 100 = 500.

This article aims to determine MW and MWD of polyimides via gel permeation chromatography (GPC) by using solution imidization and thus not having to deal with the occurrence of the polyelectrolyte effect. Therefore, the overall objective of this paper is to establish the proper chromatographic conditions required to carry out this analysis with the use of polystyrene (PS) standards for calibration.