Report AFK0242/18 TABLE OF CONTENTS

Transcription

1 Client: Blue Dent Dental OS: 0161/ Contact: Rafael Gomes Phone: (19) Address: Rua Joaquim Jorge Port, 1272 City/State: Pirassununga/SP Zip Code: Sample Reception: 28/03/2018 Date: 02/04/2018 a 03/05/2018 TABLE OF CONTENTS 1 SAMPLE IDENTIFICATION OBJECTIVE METHODS Flexural Test Gas Chromatography coupled to Mass Spectrometry (GC-MS) Water Sorption and Solubility RESULTS Flexural Test Gas Chromatography coupled to Mass Spectrometry (GC-MS) Water Sorption and Solubility CONCLUSIONS Page 1 of 12

2 1 SAMPLE IDENTIFICATION Samples were sent by the customer and identified as described in Table 1. Figure 1 shows images of the samples as received. AFINKO Identification Table 1 Sample Identification. Client Identification AFK PMMA Block 2 OBJECTIVE Figure 1 - Images of sample AFK in stick and wafer formats. The objective of this work was to characterize 01 (one) sample of PMMA, through flexural, water absorption, solubility and gas chromatography coupled to mass spectrometry (GC-MS) tests. Page 2 of 12

3 3 METHODS 3.1 Flexural Test This test is used for data acquisition of flexural properties for control and specification of plastic materials as well as for qualitative characterization and for research and development. The conditions of the flexural test can be seen in Table 2. Reference Standard: Table 2 Conditions of Flexural Test. ISO 10477: Dentistry Polymer-based crown and bridge materials. Temperature: 23 C RH: 50% Load Cell: 5 kn Span: 20mm Rate: 1,0 mm/min Number of Specimens: 05 Date: April, 11 th, 2018 Equipment: Instron EMIC, model To perform the test, the specimens were machined according to the conditions described in ISO Gas Chromatography coupled to Mass Spectrometry (GC-MS) Gas chromatography (GC) allows the separation of volatile molecules by the difference in boiling temperature and the differential interaction of the molecules with a stationary phase comprised of a coated silica column, using an inert gas as the mobile phase [1]. Mass spectrometry (MS) allows the detection of molecules and observation of the mass fragments produced by each molecule when ionized [1], besides allowing a possible identification of each signal according to the comparison of the fragmentation profile for each molecule with databases. The test was performed following guidelines according to ISO : Two solutions were prepared, solution A composed of acetone, with 20 ppm of hydroquinone, and solution B containing 20 ppm of hydroquinone in methanol. Briefly, the material was conditioned for 24 hours in the dark at 23 ± 2 C and 50 ± 10% humidity. After conditioning the material, prepared as a wafer by the customer according to the specifications of the standard, the sample was cryogenically fragmented into three Page 3 of 12

4 portions of about 650 mg and transferred to 10.0 ml volumetric flasks, with the exact mass noted. To each flask was added solvent A to the mark and a magnetic stir bar, capped and kept under stirring at room temperature for 72 hours. After this period, 2.00 ml of the solution was transferred to a new 10.0 ml volumetric flask, followed by addition of 0.1 ml of the internal standard solution (cyclohexanol in solution B, 35.0 mg.ml -1 ), and the flask filled to the mark with solution B. The resulting suspension was centrifuged (3000 x g, 10 minutes, 23 C) for separation of the precipitated polymer material, and 2.00 ml of the supernatant was transferred to a glass vial and taken for GC-MS analysis. For the construction of the calibration curve, solution C was prepared, containing a mixture of solutions A and B in a ratio of 1:4, plus the internal standard at the same concentration present in the analyzed samples (350 μg.ml -1 ). Solution C was used to prepare a stock solution of the MMA standard with concentration of 800 μg.ml -1. Mixtures in different proportions of solution C and MMA stock solution were prepared and used to construct the calibration curve, in the range of μg.ml -1. The calibration curve by internal standard method was obtained through the linear relationship between the concentration of the MMA standard and the chromatographic peak area ratio of MMA standard and the internal standard (A' MMA /A' I.S. ). The concentration of MMA in sample solutions (c MMA ) was calculated by evaluating the ratio of MMA and internal standard peak areas in the extracted samples (A MMA /A I.S. ), using the linear regression equation obtained by the calibration curve. The amount, in mg, of the MMA molecule in the solutions of the AFK sample was obtained by using equation 1 and the residual monomer content in the sample obtained by the application of equation 2. [ ] (1) (2) Analyses were performed on a Shimadzu QP-2010 gas chromatograph coupled to a TQ-8040 mass spectrometer. The detector was used in fullscan mode, with m/z ranging from The instrumental conditions of the method are described in table 3. Analyses were performed on April 16 th, Page 4 of 12

5 Table 3 - Parameters used in GC-MS analysis. Column Restek Rtx5-MS - 30 m 0.25 mm i.d., coating 0.25 μm Heaing Program for GC column Rate ( C.min -1 ) Temperature ( C) Hold for (minutes) Total analysis time: 19 minutes Injector temperature = 200 C Flow gas = He1,2 ml.min -1 Interface temperature = 250 C Injection volume = 1,0 µl Detector temperature = 250 C Split ratio = 1: Water Sorption and Solubility The water absorption was determined based on ISO : "Dentistry - Base polymers - Part 1: Dental base polymers" and ISO 10477: "Dentistry - Crown and bridge based polymer materials ". The test specimens were measured for volume calculation (V), dried using a desiccator in an oven at (37 ± 1) C, cooled and weighed every 24 hours until mass stabilization with 0.1 mg precision was obtained (m 1 ). After drying, the specimens were immersed in a bath of distilled water for 7 days at 37 ± 1 C. (m 2 ). After the immersion the specimens were dried with absorbent paper and weighed The sample was reconditioned in a desiccator until the variation of the mass of the specimens in a period of 24 hours was less than 0.1mg. The final mass was recorded (m 3 ) and used for calculating solubility and water sorption. The calculation of the water absorption (µg/mm 3 ) is performed according to equation 3 and the solubility calculation is performed according to equation 4. m2 m3 Water Sorption ( g/mm 3 ) V (3) m1 m3 Solubility ( g/mm 3 ) V (4) The analysis was performed between April 10 th and May 3 rd, Page 5 of 12

6 4 RESULTS 4.1 Flexural Test Table 4 shows the mechanical properties in flexion of the analyzed sample. Figure 2 shows the stress curves as a function of bending deformation of the same. Table 4 Flexural Mechanical Properties of sample AFK Sample C.P Flexural Strength (MPa) AFK , , , , ,80 Mean 101,13 Standard Deviation 12,64 Figure 2 - Flexural stress x strain curves of sample AFK Gas Chromatography coupled to Mass Spectrometry (GC-MS) First, the calibration curve for the MMA standard was obtained by integrating the area of the analytical signal produced by the injection, in triplicate, of the solutions prepared in the concentrations of 10; 100; 200; 400; 600 and 800 μg.ml -1. Figure 3 shows a chromatogram obtained for a curve sample with c MMA = 200 μg.ml -1. Page 6 of 12

7 Figure 3 - Example of chromatogram obtained for the construction of the calibration curve of MMA. The signal related to the MMA standard was observed with a retention time of 1.88 minutes, and the signal referring to the I.S. cyclohexanol was observed with a retention time of 3.66 minutes. The signal at 1.65 minutes relates to the reaction product between acetone and methanol (2,2-dimethoxypropane), and the signal at minutes was identified as hydroquinone. After analyzing all the points of the curve in triplicate, the analytical signals referring to the MMA standard and the I.S. were integrated and their areas obtained. After the area values were taken, the calibration curve was constructed from the area ratio and MMA standard concentration values, obtaining an equation adjusted through the linear regression of the data, as shown in figure 4. Page 7 of 12

8 Razão Áreas (MMA/I.S.) 2,5 Curva de calibração MMA y = 0,0029x + 0,0146 R² = 0, ,5 1 0, Concentração MMA (μg.ml -1 ) Figure 4 - Calibration curve for the MMA standard. The linear adjustment presented a high correlation coefficient (R 2 = ), above the minimum required by the standard (0.990). The angular coefficient (a) and the intercept (b) were obtained, with values of and respectively. With the values of angular coefficient and intercept, the analyzes of the sample solutions were continued. Figure 5 shows the chromatograms obtained for the three solutions produced for the AFK sample. Page 8 of 12

9 Figure 5 - Chromatograms obtained for the three sample solutions from AFK The analytical signals for the MMA molecule and the internal standard were integrated, obtaining the area of each signal. After the integration, the area ratio was used to calculate the MMA concentration in samples, applying the area ratio obtained for each sample in the regression equation obtained by the calibration curve. By using the concentration values obtained in equation 3, it is obtained the mass quantity of MMA in the initial solution, and further using this value in equation 4 it is obtained the residual monomer content in the sample, as shown in table 5. Page 9 of 12

10 Table 5 - MMA content in solutions and residual monomer in sample AFK Sample AFK AFK180583_1 AFK180583_2 AFK180583_3 Sample mass (mg) 652,62 652,29 652,45 MMA area (AU) I.S. área (AU) Area Ratio (A MMA /A I.S. ) 0,621 0,604 0,641 c MMA (final solution) (μg.ml -1 ) 207,28 201,27 214,04 m MMA (sample) (mg) 10,364 10,063 10,702 Residual monomer content 1,59% 1,54% 1,64% Mean residual monomer content of 1.59% ± 0.05% was obtained for the sample AFK180583, below the upper limit indicated by ISO :2013 (4.5% for type 2 resins, and 2,2% for resins of other types). 4.3 Water Sorption and Solubility Table 6 shows the mass values obtained for sample AFK during water absorption and solubility tests. Table 6 - Results of the water sorption and solubility tests for sample AFK Water Volume Solubility CP M (mm³) 1 (g) M 2 (g) M 3 (g) Sorption (µg/mm³) (µg/mm³) ,2 14, , ,4565 7,1 0, ,2 14, , ,3738 6,9 0, ,5 14, , ,3630 7,1 1, ,0 14, , ,4002 7,1 0, ,2 14, , ,4187 6,4 0,9 Mean 6,9 0,7 Standard Deviation 0,3 0,4 Page 10 of 12

11 5 CONCLUSIONS Sample AFK had an average flexural strength of 110 MPa, wich exceeds the limit established by ISO (four or more samples 50 MPa). Sample AFK showed residual monomer content of 1.59% ± 0.05%, within the maximum limit established by ISO : (4,5% for type 2 resin and 2,2% for types 1,3,4,5 resins.) The sample presented a water sorption value of 6.9 μg/mm³ and a solubility of 0.7 μg/mm³. According to ISO the maximum absorption value allowed is 40 μg / mm³ and that of solubility 7.5 μg / mm³. The maximum values for ISO are 32 μg / mm³ and 8.0 μg / mm³ for absorption and solubility, respectively. Table 7 summarizes the results obtained. Table 7 - Summary of results. Property AFK Specification ISO ISO Status Flexural Strength (MPa) Ok Residual Monomer Content (%) 1,59-4,5 Type 2 2,2 Type 1,3,4,5 Ok Water Sorption (μg/mm³) 6, Ok Solubility (µg/mm³) 0,7 7,5 8,0 Type 2 1,6 Type 1,3,4,5 Ok São Carlos, May 3 rd, Dr. Bruno Perlatti Researcher Dr. Marcio Kobayashi Technical Manager Page 11 of 12

12 References [1] HUBSCHMANN, H.-J. Handbook of GC/MS: Fundamentals and Applications, 2nd Ed. New Jersey: Wiley, Concluding Remarks - The results presented here refer exclusively to the analyzed samples under the conditions in which the tests were performed, not being extended to any batches, even if similar. - The laboratory is not responsible in case of misinterpretation or misuse that can be made of this document. - The reproduction of this document must be carried out in full. - The samples will be kept for three months or as determined in the budget / contract. -- End of -- Page 12 of 12