TY - THES

T1 - Development of thermo-responsive silicon resins for safety applications

AU - Arceta Lozano, Alan

N1 - no embargo

PY - 2024

Y1 - 2024

N2 - The master¿s thesis is aimed at the development of smart polymer coatings which allow an early detection of overheating events in battery systems by the thermal release of tracer gases, detected in a consecutive step by using specific metal oxide (MOx) sensors. To achieve this, an innovative thiophene-based Diels-Alder (DA) adduct (ARZ_5) was synthetized and investigated, which liberates a tracer gas based on the reversibility of the DA reaction. It is well known that the retro Diels-Alder reaction (rDA) possesses the capability of recovering the reactants at a specific temperature. Here, the reactants are obtained in the gas phase, if the cleavage temperature has a value above their boiling point. In particular, a volatile thiophene species will be released, acting as a tracer gas that can be detected by a wide variety of MOx sensors. The reversibility of the reaction was investigated by Fourier-Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Evolved Gas Analysis coupled to an Infrared spectrometer (EGA-FTIR) and also by Evolved Gas Analysis coupled to a mass spectrometer (EGA-MS). Furthermore, ARZ_5 was attached to a multi-functional thiol (ARZ_5-PETMP) through a thiol-Michael addition and subsequently, implemented at varying concentrations into a thiol-acrylate network. Smart polymer systems were obtained, which were able to emit various amounts of tracer gases (SYS_A, SYS_B, SYS_C) at a defined temperature. The preparation of the expected products was corroborated by analyzing their characteristic FTIR bands and the release of the thiophene moieties was probed by the afore mentioned characterization techniques. Moreover, in order to prove the detection of the thiophene by MOx sensors, SYS samples were tested in a sensor test setup consisting of a heating chamber where the tracer gases were released. The gases were then detected by a coupled chamber equipped with MOx sensors. In a last step of this thesis, ARZ_5-PETMP was also attached through a thiol-ene reaction to a commercially available silicon matrix used for insulation purposes in mica composites to produce a new class of smart polymer resin (SYS_ACR-JO) system. This final system was firstly thermally characterized and finally, mica sheets were impregnated with it to prepare a thermal insulation material with an additional gas release capability. Results showed that ARZ-5, as well as systems SYS_A, SYS_B, SYS_C and SYS_ACR-JO successfully emitted thiophene when reaching the rDA temperature in the range of 100 °C. It could be demonstrated that the released amount of thiophene increased with rising content of ARZ_5-PETMP in the polymer matrix. Further mechanical and ageing tests of the developed formulations will be needed to fully study the systems before bringing them into real battery applications.

AB - The master¿s thesis is aimed at the development of smart polymer coatings which allow an early detection of overheating events in battery systems by the thermal release of tracer gases, detected in a consecutive step by using specific metal oxide (MOx) sensors. To achieve this, an innovative thiophene-based Diels-Alder (DA) adduct (ARZ_5) was synthetized and investigated, which liberates a tracer gas based on the reversibility of the DA reaction. It is well known that the retro Diels-Alder reaction (rDA) possesses the capability of recovering the reactants at a specific temperature. Here, the reactants are obtained in the gas phase, if the cleavage temperature has a value above their boiling point. In particular, a volatile thiophene species will be released, acting as a tracer gas that can be detected by a wide variety of MOx sensors. The reversibility of the reaction was investigated by Fourier-Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Evolved Gas Analysis coupled to an Infrared spectrometer (EGA-FTIR) and also by Evolved Gas Analysis coupled to a mass spectrometer (EGA-MS). Furthermore, ARZ_5 was attached to a multi-functional thiol (ARZ_5-PETMP) through a thiol-Michael addition and subsequently, implemented at varying concentrations into a thiol-acrylate network. Smart polymer systems were obtained, which were able to emit various amounts of tracer gases (SYS_A, SYS_B, SYS_C) at a defined temperature. The preparation of the expected products was corroborated by analyzing their characteristic FTIR bands and the release of the thiophene moieties was probed by the afore mentioned characterization techniques. Moreover, in order to prove the detection of the thiophene by MOx sensors, SYS samples were tested in a sensor test setup consisting of a heating chamber where the tracer gases were released. The gases were then detected by a coupled chamber equipped with MOx sensors. In a last step of this thesis, ARZ_5-PETMP was also attached through a thiol-ene reaction to a commercially available silicon matrix used for insulation purposes in mica composites to produce a new class of smart polymer resin (SYS_ACR-JO) system. This final system was firstly thermally characterized and finally, mica sheets were impregnated with it to prepare a thermal insulation material with an additional gas release capability. Results showed that ARZ-5, as well as systems SYS_A, SYS_B, SYS_C and SYS_ACR-JO successfully emitted thiophene when reaching the rDA temperature in the range of 100 °C. It could be demonstrated that the released amount of thiophene increased with rising content of ARZ_5-PETMP in the polymer matrix. Further mechanical and ageing tests of the developed formulations will be needed to fully study the systems before bringing them into real battery applications.

KW - Intelligente Polymerbeschichtungen

KW - Tracergase

KW - Thermische Freisetzung

KW - Silikonmatrix

KW - Metalloxidsensoren

KW - Retro-Diels-Alder-Reaktion

KW - Thiol-Acrylat-Netzwerk

KW - Smart polymer coatings

KW - Tracer gases

KW - Thermal release

KW - Silicon matrix

KW - Metal oxide sensors

KW - Retro Diels-Alder reaction

KW - Thiol-acrylate network

M3 - Master's Thesis

ER -