Moisture Content of Plastics

Moisture Content of Plastics

Moisture content is an important property of plastic materials that can impact their performance and properties. The moisture content of plastic can vary due to the manufacturing process, storage conditions, or environmental exposure. The presence of moisture in plastic can cause a range of negative effects, including dimensional instability, reduced strength, and poor surface finish. 

Gravimetric analysis, Karl Fischer titration, and infrared spectroscopy are common methods for measuring the moisture content of plastic. 

1. Gravimetric analysis: This method involves weighing a sample of the plastic material before and after drying it to remove moisture. The sample is first weighed in its original state, and then it is heated in an oven at a specific temperature for a specified time period to remove all moisture. After the sample has been dried, it is re-weighed, and the difference between the initial weight and the final weight provides the moisture content of the plastic.
2. Karl Fischer titration: This method involves adding a reagent to the sample that reacts with water, and measuring the resulting change in electrical conductivity. The amount of moisture in the sample can be determined by comparing the electrical conductivity before and after the addition of the reagent.
3. Infrared spectroscopy: This method involves analysing the absorption of water molecules in the plastic using infrared radiation. The amount of moisture in the sample can be determined by comparing the absorption of the sample to the absorption of a dry reference sample.

The moisture content of plastic is a critical property that can impact its performance and properties. Proper measurement and control of the moisture content of plastic is necessary to ensure its quality and performance.

Video 01: Eco Karl Fischer Titrator from Metrohm for moisture determination

Other Useful Resources
Scanning electron microscope testing
Application of uv spectroscopy
Differential scanning calorimetry testing
High performance liquid chromatography testing