Polymers for realizing energetic materials with tailored performance

过去20年，能源储存和释放、安全问题和进入太空成为西方经济体的关键技术领域。塑料和复合材料等以聚合物为基础的材料在这些新技术中发挥着重要作用。含能聚合物被定义为在短的分解时间内产生大量能量的聚合物，这通常是由于其主链上存在叠氮和硝基。当它们与氧化剂和金属颗粒等固体燃料混合时，可用作固体推进剂、炸药配方和气体发生器组合物(如汽车安全气囊或其他炸药驱动的安全装置)的粘结剂或核心组件。这项研究的目的是开发创新的工艺和材料，使聚合物在含能材料领域得到更多的使用。更具体地说，我的最终目标将是获得新型聚合物基含能材料，只要有可能，就可以使用可生物降解的预聚体，以最小的环境足迹安全地加工和使用。还必须寻求新的制造技术，以充分利用新的含能粘结剂的好处。其中，添加制造(AM)在部件设计和受控能量释放方面提供了一系列全新的可能性。AM技术很快将允许更智能的高能材料驱动系统具有量身定制的性能。虽然塑料材料的AM现在已经很成熟，但它在含能材料领域的等价物仍然是一项处于发展早期的技术。热塑性材料通常更容易回收利用。大多数塑料产品都是为满足特定机械性能而设计的。此外，以含能聚合物为基础的塑料和弹性体也必须达到令人满意的燃烧性能。到目前为止，在单一的热塑性产品中几乎不可能达到这两个标准，因为提高燃烧速度的化学成分，如硝基的存在，由于结晶度降低，往往对机械性能不利。一些AM原料要求具有热塑性。为了加强含能聚合物的这一特性，将在两个方面开展工作：1)对现有含能聚合物进行化学修饰；2)合成新的含能聚合物，以扩大可能的共混物的研究范围。我们将特别注意我们最近开始开发的多四唑和多三唑。这一创新的研究计划是对当代高能材料行业面临的挑战的回应。AM将减少制造足迹、按需制造和快速成型高能部件，如智能、更安全和可回收的安全气囊、超高速推进系统或微型卫星的先进推进器。

The last two decades have seen energy storage and release, security issues and access to space emerged as key technological areas of western economies. Polymer based materials, such as plastics and composites, have an important role to play in these novel technologies. Energetic polymers are defined as polymers that produce a significant amount of energy in a short decomposition time, often owing to the presence of azide and nitro groups on their backbone. When mixed with oxidizers and solid fuels such as metal particles, they find use as binders or core components in solid propellants, explosives formulations, and gas generator compositions such as automotive airbags or other explosive actuated safety devices. This research is aimed at developing innovative processes and materials allowing for an increased use of polymers in the field of energetic materials. More specifically, my final objective will be to obtain novel polymer based energetic materials that can be safely processed and used with minimal environmental footprint, employing biodegradable prepolymers whenever possible. Novel fabrication techniques must also be sought to fully exploit the benefits of new energetic binders. Among them, additive manufacturing (AM) offers an entirely new range of possibilities in terms of part designs and controlled energy release. AM technology will soon allow smarter energetic material driven systems with tailored performance. While AM of plastic materials is now well established, its equivalent in the field of energetic materials remains a technology at its early stage of development. Thermoplastic materials are generally easier to recycle. Most plastics products are designed to meet specific mechanical properties. Energetic polymers-based plastics and elastomers must, in addition, also reach satisfactorily combustion properties. These two criteria have so far been almost impossible to obtain in a single thermoplastic product, as the chemical composition that enhances the burning rate, such as the presence of nitro groups, is often detrimental to mechanical properties due to a reduced cristallinity. Thermoplasticity is required for some AM feedstocks. In order to enhance this characteristic in energetic polymers efforts will be deployed on two fronts: 1) the chemical modification of existing energetic polymers and 2) the synthesis of new energetic polymers to enlarge the set of possible blends to investigate. A special attention will be given to polytetrazoles and polytriazoles that we have recently started to develop. This innovative research program is an answer to contemporary challenges faced by the energetic materials industry. AM will bring reduced manufacturing footprint, on-demand fabrication and rapid prototyping of energetic components such as smart, safer and recyclable airbags, hypervelocity propulsion systems or advanced thrusters for micro-satellites.