The Effect of Curing Temperature and Time on the Acoustic and Optical Properties of PVCP

Abstract

Polyvinyl chloride plastisol (PVCP) has been increasingly used as a phantom material for photoacoustic and ultrasound imaging. As one of the most useful polymeric materials for industrial applications, its mechanical properties and behaviour are well-known. Although the acoustic and optical properties of several formulations have previously been investigated, it is still unknown how these are affected by varying the fabrication method. Here, an improved and straightforward fabrication method is presented and the effect of curing temperature and curing time on PVCP acoustic and optical properties, as well as their stability over time, is investigated. Speed of sound and attenuation were determined over a frequency range from 2 to 15 MHz, while the optical attenuation spectra of samples was measured over a wavelength range from 500 to 2200 nm. Results indicate that the optimum properties are achieved at curing temperatures between 160 • C and 180 • C, while the required curing time decreases with increasing temperature. The properties of the fabricated phantoms were highly repeatable, meaning the phantoms are not sensitive to the manufacturing conditions provided the curing temperature and time are within the range of complete gelation-fusion (samples are optically clear) and below the limit of thermal degradation (indicated by the yellowish appearance of the sample). The samples' long term stability was assessed over 16 weeks and no significant change was observed in the measured acoustic and optical properties. Index Terms-Acoustic properties, optical properties, phantoms, photoacoustics, polyvinyl chloride plastisol, ultrasound.

Investigation of PolyVinyl Chloride Plastisol Tissue-Mimicking Phantoms for MR- and Ultrasound-Elastography

“…However, the values measured at 1 MHz agree with those found in the literature over a larger range of frequencies, as illustrated in Figure 1. Second, the density and speed of sound used in this study were taken from the literature [28,30,32,33,35,40,42,43,51,52]. They are here assumed to be the same for all the mass ratios of resin to plasticizer.…”

“…The density of water, the speed of sound in water, the density of the specimen (regardless of mass ratio between resin and plasticizer M Res/Plast , in accordance with [42], who used PVCP from the same manufacturer) and the speed of sound in the specimen are assumed to have values of 1,000 kg.m −3 , 1,500 m.s −1 , 1,000 kg.m −3 and 1,400 m.s −1 , respectively (values from Ref. 28, who used PVCP from the same manufacturer, and in accordance with [30,32,40,43] [44,46]).…”

“…T 2 values (averaged over all cellulose mass ratios) decrease by 10% (50 ms-44 ms) between mass ratio between resin and plasticizer M Res/Plast from 40 to 50%; for M Res/Plast from 50% to 70%, no further change in T 2 is observed. The T 1 values of PVCP (averaged over all cellulose mass ratios) FIGURE 1 | The acoustic attenuation coefficients measured at 1 MHz in the tested Plastisol phantoms (colored signs) are compared to typical values from the literature for biological soft tissues (green colored area) [44] and to similar PVCP TMP (gray and black curves) [30,32,33,35,40,51,52] over the acoustic frequency range 0.5-3 MHz.…”

“…5,5,10,15,20,30,40,50,60,80, 100, 150, and 200 ms. Common relevant imaging parameters for both sequences are: matrix 192 x 192, field of view 340 mm × 340 mm, slice thickness 6 mm, bandwidth 789 Hz.px −1 .…”

Measurement of the temperature-dependent speed of sound and change in Grüneisen parameter of tissue-mimicking materials

“…The tissue-mimicking materials (TMMs) included in the study were agar-based materials [4], [5], copolymer-in-oil [6], gel wax [7], polyvinyl chloride plastisol (PVCP) [8] and silicone [9]. For each TMM, planar samples of 10 ± 5 mm thickness and 60 mm diameter were prepared with an embedded T-type thermocouple (5TC-TT-TI-36-1M-SMP-M IEC PFA-insulated, Omega Engineering Limited, Manchester, U.K.).…”