Improvement Of Testing Method For Additives In Nylon 66 Polymer

Nylon 66 is strong and can resist high temperature and wear. The Nylon 66 tire cord fabric is the framework material for high-quality tires. Additives like KI, TiO2 added in the polymerization process of nylon 66 have a very important influence on various physical properties of nylon 66. So it is of great significance to study the additive-testing methods during the polymerization of nylon 66. Microwave is an electromagnetic wave whose frequency ranges from 300 MHz to 300 GHz. Due to its advantage of strong penetrating ability and selective heating, microwave has been widely applied in fields like biology and chemical engineering. This thesis will set up new methods of testing additives in nylon 66 polymer by combining microwave with the existing methods of testing KI and TiO2.。(1) Modify the method of testing the amount of KI. According to the results coming from microwave extraction and electric heating extraction respectively, not only is there less time needed for the former, the amount of sodium extracted is also higher. This means the extraction efficiency of microwave extraction is higher than that of electric heating extraction. The optimum conditions of microwave extraction were obtained by designing an orthogonal experiment: 2 grams of sample, 80% fire for extraction and 10-minute boiling time. A comparison experiment was carried out on two kinds of extraction methods and the t test was used to test, which showed that the results of these two kinds of tests were basically consistent. For the cooling of the extraction liquid, water bath plus magnetic stirring was proposed, and the series test was replaced by parallel test. Testing the reproducibility of the unmodified method and the modified one shows better repeatability. With the improved test method, the extraction time decreases by 80%, and the extraction efficiency is improved by 90%.(2) Modify the method of testing the amount of TiO2. During the ashing stage,replace the crucible used to ash samples in a muffle furnace with an evaporating dish which has a larger surface for the feasibility experiment. Experiments proved feasibility. During the heating and dissolving phase, experiments of microwaveheating and electric heating are conducted and compared, and the result showed that microwave heating is not only feasible, but also even superior to electric heating. In the stage of cooling and diluting, a suspended cooling method, which uses a homemade evaporation dish and an external blowing device to accelerate cooling,was designed. The diluting method of magnetic stirring plus cryogenic cooling is also used. Testing the reproducibility of the unmodified method and the modified one shows better repeatability. After modification, the time taken by the whole process is shortened by 60%. Based on this, a more rapid and efficient testing method of Ti O2 content was established.