Analysis of the testing process of polymers for special coatings

In the modern industrial field, special coatings are widely used in aerospace, automobile manufacturing, shipbuilding and other fields due to their excellent corrosion resistance, high temperature resistance and special functional requirements. The performance of polymers, one of the core components of special coatings, directly affects the overall quality of the coating. Therefore, strict testing of polymers is crucial. This article will introduce the testing process of polymers for special coatings in detail to help industry practitioners better control product quality.

Sample collection and pretreatment

The first step of the test is sample collection. To ensure the representativeness of the data, samples need to be randomly selected from different batches or production links, and their source, production date and other information need to be recorded. The collected samples need to be pretreated, including drying, crushing or dissolving steps, to ensure the accuracy of subsequent tests. For example, some polymers need to be dried at a specific temperature to remove moisture to avoid affecting the test results.

Physical property testing

Physical property testing is the basic link in evaluating polymer quality, mainly including the determination of indicators such as density, viscosity, and melt index. Density testing is usually done by pycnometer or buoyancy method, while viscosity testing is done by rotational viscometer or capillary viscometer. Melt index testing evaluates the fluidity of polymers, which is critical to the application performance of coatings.

Chemical composition analysis

Chemical composition analysis aims to determine the molecular structure and purity of polymers. Commonly used methods include infrared spectroscopy (IR), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). IR spectroscopy can identify the functional groups of polymers, NMR can provide more detailed molecular structure information, and GPC can determine the molecular weight distribution of polymers, which has a direct impact on the film-forming properties of coatings.

Thermal properties and weathering resistance testing

Special coatings are often used in extreme environments, so the thermal stability and weathering resistance of polymers are critical. Thermogravimetric analysis (TGA) can determine the thermal decomposition temperature of polymers, while differential scanning calorimetry (DSC) can evaluate their glass transition temperature. In addition, artificial accelerated aging tests can simulate the effects of long-term UV exposure or hot and humid environments on polymers.

Through the above testing process, enterprises can fully understand the performance of polymers used in special coatings and ensure the reliability and market competitiveness of the final products.