Thermo-mechanical characterisation of a nanosized particle filled underfill
This paper describes work carried out as part of a larger project aimed at the development of nanosized particle filled underfill material. Several characterisation experiments have been applied to study the influence of these particles on the curing behaviour and the thermomechanical properties such as the coefficient of thermal expansion, geltime, glass transition temperature, and modulus. Constitutive models are assessed for their ability to describe the observed behaviour
Modulated temperature differential scanning calorimetry: Cure, vitrification, and devitrification of thermosetting systems
Abstract Vitrification of a reacting thermosetting system occurs when its glass transition temperature, T g , rises to the reaction temperature, T . This phenomenon can occur in both isothermal and non-isothermal conditions, depending on the temperatures or heating rates used, the reactivity of the system, and the evolution of T g with conversion. After vitrification, the reaction proceeds in mobility-restricted conditions. In non-isothermal experiments devitrification is observed when the reaction temperature again surpasses T g of the vitrified resin. The cure process of two epoxy thermosetting systems and an inorganic polymer glass has been studied using modulated temperature differential scanning calorimetry (MTDSC). A normalized mobility factor, which is directly based on the experimental heat capacity evolution, is proposed. For both organic resins, it is shown that the points for which this mobility factor equals 0.5 can be used to quantify vitrification and devitrification. Preliminary results indicate a relation between the evolution of the heat flow phase and the chemorheological transformations. The mobility factor derived from the heat capacity is compared to a normalized diffusion factor calculated using the non-reversing heat flow and chemical kinetics modelling. For the organic resins studied, both factors coincide. Therefore, the mobility factor can be used as a direct measurement of the change in the rate of reaction due to mobility restrictions when T g of the reacting system approaches T . Isothermal and non-isothermal MTDSC experiments enable the reaction mechanism, the vitrification and devitrification process, and models for diffusion control to be studied, and temperature-time transformation or continuous-heating transformation diagrams for improved thermoset processing conditions to be developed.
Music and Ethical Responsibility
Introduction 1. Meaning and ethics in music 2. Experiencing music 3. Framing elements of musical experience 4. Improvisation and ethical responsibility 5. Musical improvisation as festival 6. Music, proximity, ethics 7. Ethical responsibility and other people's music Conclusion: ethical responsibility in musical experience.