FTIR-Plastics: a Fourier Transform Infrared Spectroscopy dataset for the six most prevalent industrial plastic polymers.

Two datasets are presented: FTIR-Plastics-C4 and FTIR-Plastics-C8, comprising 6,000 spectra obtained through Fourier Transform Infrared Spectroscopy (FTIR) applied to the six most used synthetic polymers: Polyethylene Terephthalate (PET), High-Density Polyethylene (HDPE), Polyvinyl Chloride (PVC), Low-Density Polyethylene (LDPE), Polypropylene (PP), and Polystyrene (PS). The key feature of the datasets lies in the FTIR analysis, which reports the percentage transmittance as the intensity measure as a function of the wavelength of an Infrared light source, expressed as wavenumber (with units in cm^-1). FTIR analysis was performed using a Jasco FTIR PRO 4x spectrophotometer with a wavenumber resolution setting of 8 cm^-1 for FTIR-Plastics-C8 and 4 cm^-1 for FTIR-Plastics-C4, both employing a configuration of 32 scans and a range from 4000 to 400 cm^-1. The datasets are presented in CSV (comma-separated values) format, including the following information (per each column):

• IDE: unique identifier of the sample.

• Polymer: type of synthetic polymer (PET, HDPE, PVC, LDPE, PP, or PS).

• Technique: Type of technique used (FTIR).

• Sample: polymer sample number.

• BR: scanning configuration (32).

• RST: resolution configuration (8 or 4 cm^-1).

• Data (x) y Data(y): 1884 pairs of columns for FTIR-Plastics-C8 and 3751 pairs of columns for FTIR-Plastics-C4, representing values on the "x" axis (wavenumber) and the "y" axis values associated with molecular vibration intensities, indicating the transmittance (%), which differentiates each polymer.

Additionally, the files generated by the Jasco spectrophotometer for each polymer are provided, which were standardized by adding a header with the following structure:

• TITLE SAMPLE NAME: referring to the name of the analyzed polymer.

• DATA TYPE: specifying the characterization technique.

• MEASUREMENT INFORMATION: equipment used for data collection.

• MODEL NAME: name of the equipment used.

• SERIAL No: serial number assigned to the equipment used.

• ACCESSORY: complementary device integrated into the equipment.

• LIGHT SOURCE: standardized light source related to the DLATGS detector.

• RESOLUTION: parameters are used to distinguish the wavenumber in the analyzed materials.

• XUNIT/HORIZONTAL AXIS: referring to the unit’s title assigned on the x-axis.

• YUNITS/VERTICAL AXIS: referring to the unit’s title designated on the y-axis.

• FIRSTX: initial value set for the x-axis.

• FIRSTY: initial value set for the y-axis.

• LASTX: final value set for the x-axis.

• LASTY: final value set for the y-axis.

• NPOINTS: total data points in the file.

Data collection was carried out meticulously, following specific steps to ensure the accuracy and reliability of the results. The calibration certificates issued by the supplier (calibration_certificate.pdf) corresponding to the equipment used in the experiments and data collection that give rise to these databases are attached.