ASTM F2778-09(R2020) pdf free download

ASTM F2778-09(R2020) pdf free download.Standard Test Method for Measurement of Percent Crystallinity of Polyetheretherketone (PEEK) Polymers by Means of Specular Reflectance Fourier Transform Infrared Spectroscopy (R-FTIR)
1. Scope
1.1 This test method describes the collection of absorption spectra of polyetheretherketone (PEEK) polymer in filled and unfilled grades, as supplied by a vendor, and the subsequent calculation of the percent crystallinity. The material is evalu- ated by infrared spectroscopy. The intensity (height) of the absorbance peaks is related to the amount ofcrystalline regions present in the material. 1.2 This test method can be used for PEEK consolidated forms, such as injection molded parts, as long as the samples are optically flat and smooth. 1.3 The applicability of the infrared method to industrial and medical grade PEEK materials has been demonstrated by scientific studies. 2,3 Percentage of crystallinity is related to R-FTIR measurement by calibration through wide-angle x-ray scattering (WAXS) crystallinity measurements. 2,3 It is antici- pated that this test method, involving the peak heights near 1305 cm -1 and 1280 cm -1 , will be evaluated in an Interlabora- tory Study (ILS) conducted according to Test Method E691. 1.4 This test method does not suggest a desired range of crystallinity for specific applications. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental prac- tices and determine the applicability ofregulatory limitations prior to use. 1.7 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Significance and Use
4.1 Mechanical properties of PEEK polymers, such as stiffness or yield strength, are influenced by the level of crystallinity. 5 The reported crystallinity index determined by this test method has been correlated with percent crystallinity in PEEK polymers by wide-angle X-ray scattering (WAXS) experiments. 2,3 4.2 This test method may be useful for both process development, process control, product development, and re- search.
5. Interferences
5.1 Samples must be smooth and optically flat over the area of investigation, typical of injection-molded specimens. They shall be sufficiently thick (for example, 1 to 2 mm) such that there is no detectable back surface reflected radiation. 5.2 Samples shall be sized appropriately to be accommo- dated in the FTIR apparatus.
6. Apparatus
6.1 Infrared Spectrometer: 6.1.1 An infrared spectrometer capable of recording a re- flection absorption spectrum over the range of 500 cm -1 to 1500 cm -1 is necessary. 6.1.1.1 A minimum scan resolution of 4 cm -1 shall be used. 6.1.1.2 A minimum aperture of 360 × 360 µm shall be used. 6.1.1.3 A minimum of 100 scans shall be collected per spectrum. 6.1.2 Software capable of using the Kramers-Kronig trans- form algorithm to derive the absorbance spectra. 6.2 Specimen Holder—Equipment capable of accurately positioning the sample under the orifice and allowing the sample to be in focus. 6.3 Samples Preparation Equipment—Equipment capable of producing optically flat and optically thick samples.
7. Preparation of Apparatus
7.1 Prior to testing, the FTIR dewer chamber should be filled with liquid nitrogen until peak-to-peak signal in trans- mission mode is over 10.
8. Calibration and Standardization
8.1 Validation and calibration should be conducted weekly by running a validation check of the infrared spectrometer based on the manufacturer’s instructions. 8.2 A background scan should be conducted at the start of testing and every 30 min thereafter for the duration of testing while using the same scanning settings as the test parameters dictate. The background scan should be taken from a com- pletely reflective surface.