Plasticizer loading in acoustic encapsulants - Springer
acoustic windows, to encapsulate transducers to protect them from the ocean environment, and to serve as an acoustic medium in sonar arrays. The dynamic mechanical behaviors of these materials change when they absorb plasticizers such as transducer ll uids (e.g., castor oil, hydrocarbon distillates and syn-thetics, silicone uids).
Plasticizer loading in acoustic encapsulants | SpringerLink
The plasticizers used in this effort were sonar transducer fluid (castor oil, per MIL-T-17128C), Isopar-L isoparaffinic hydrocarbon from ExxonMobil, distilled water, and dioctyl phthalate (DOP) (≥99 %) and dioctyl terephthalate (DOTP) (≥98 %) both from Sigma-Aldrich. Preparation of polyurethane samples
Dynamic mechanical response of plasticizer-laden acoustic
Acoustic encapsulants are used in US Navy sonar hardware to protect internal electronics from the ocean environment. As a result, these materials must also serve as an acoustically clear medium. Two sources of signal loss in these materials are reflection and damping.
Plasticizer loading in acoustic encapsulants - DeepDyve
Plasticizer loading in acoustic encapsulants Rice, Matthew Journal of Thermal Analysis and Calorimetry, Volume 117 (2) – Aug 1, 2014 Read Article Download PDF Share Full Text for Free (beta) 4 pages Article Details Recommended References Bookmark Add to Folder Cite Social Times Cited: Web of Science Journals /
Journal of Thermal Analysis and Calorimetry | Volume 117, issue 2
Plasticizer loading in acoustic encapsulants Authors. Matthew Rice; Content type: OriginalPaper Published: 27 April 2014; Pages: 661 - 664; Effect of
- Are thermoplastic polyurethane encapsulants degraded in underwater acoustic sensors?
- Degradation of thermoplastic polyurethane (TPU) encapsulants used in an underwater acoustic sensor (UAS) was examined by aging in seawater, and the lifetime of TPU encapsulants was estimated using an empirical approach based on accelerated lifetime test (ALT).
- Can TPU encapsulants protect hydrophones from seawater leakage?
- TPU encapsulants can effectively protect hydrophones in UASs from seawater leakage. However, TPU encapsulants can be torn or broken apart due to the degradation of mechanical properties in seawater , , , , resulting in hydrophone failures.
- How are TPU encapsulants made?
- According to the supplier, the TPU encapsulants were produced by using an ether polyurethane consist of poly (tetramethylene glycol) (PTMG, Mw=1000 g/mol), 4,4′-methylene diphenyl diisocyanate (MDI) and 1,4-butanediol as the soft segment, hard segment and chain extender, respectively.
- How are TPU encapsulants aged?
- The TPU encapsulants were placed in seawater and aged at temperatures of 85, 100 and 110 °C. TPU encapsulants underwent a hydrolysis reaction during aging in seawater, changing the chemical structure and molecular weight of TPU.
- How does hydrolysis affect tensile strength of TPU encapsulants?
- TPU encapsulants underwent a hydrolysis reaction during aging in seawater, changing the chemical structure and molecular weight of TPU. Molecular dynamic (MD) simulation results described the hydrolysis degradation of TPU results in the decrease in tensile strength.
- Which acceleration models are used to describe the lifetime of TPU encapsulants?
- Acceleration models, including exponential, Arrhenius, Eyring and IPL equations, are described in the ALTA software , , , , . Those acceleration models were combined with the Weibull distribution model to characterize the lifetime of TPU encapsulants as a function of stress and aging time.
