Hii,

Small size of the samles can represent the properties of whole composite as the material is distributed uniformly.

Hi，

My answer is no. The composite includes the carbon, glass fibers, polymers ant others. The fibers are hard to be distributed uniformly becouse of their anisotropy. As we all know, the weight for TGA is about 5 mg. If the sample is less than 5 mg, it is hard to represent the whole composite.

Hi, thank you. Yes, you are right. I came across various papers in hybrid composites, and the authors did a TGA test, and I was wondering how the results can be reliable.

Hi, I would like to differ and say, give it a try with a larger sample. Most TGA manufacturers offer pans that can easily accommodate 40mg samples. And remember the amount of organic matter (resin) is normally a small %. Even if you have carbon fibers in as well, they will burn off at elevated temperatures under air/oxygen. Give it a try with a few samples to get your feel for homogeneity!

Dear Abrie Myburgh

Thank you for your reply. That is a good idea. Definitely, I will consider it.

Thank you.

Fariborz

The size of the samples used in a thermal analysis experiment, such as a thermogravimetric analysis (TGA), can have an impact on the results obtained and on the ability to accurately represent the properties of the material being studied. In general, smaller samples may be more susceptible to measurement errors and may not accurately represent the properties of the material as a whole.

In the case of hybrid carbon/glass fiber composites, the size of the samples used in a TGA experiment may be particularly important due to the potentially significant differences in the thermal properties of the carbon and glass fibers. If the sample size is too small, it may not contain a representative distribution of both types of fibers, which could lead to inaccurate or misleading results.

Therefore, it is generally recommended to use larger sample sizes when conducting TGA experiments on composite materials, particularly if the properties of the individual constituents (e.g., carbon and glass fibers) are expected to significantly influence the overall properties of the material. However, it may also be possible to use smaller sample sizes and apply statistical techniques, such as sample size calculations and uncertainty analysis, to account for the potential impact of measurement error and sample size on the results.

In conclusion, the small size of the samples in a TGA experiment may not accurately represent the properties of a hybrid carbon/glass fiber composite, and it is generally recommended to use larger sample sizes whenever possible to improve the accuracy and reliability of the results.