SBIR Phase II: Ultra-softening polymers from engineered thiol-based resins for additive manufacturing

小型企业创新研究(SBIR)第二阶段项目的更广泛影响/商业潜力是制造坚固的3D打印部件，这些部件可以通过商业上可用的添加剂工艺直接制造。添加制造有可能通过简化产品设计、生产和验证来彻底改变部件的生产方式，从而降低生产成本并加快交货期。添加剂技术在工业过程中的渗透已经大大放缓，因为目前无法3D打印任何硬度的部件，其材料特性与传统制造的部件相同。特别是，3D打印材料往往更容易在连续的打印层之间撕裂或断裂。在自适应3D技术公司，我们开发了一种树脂，通过在打印层之间实现共价交联，可以生产出坚固耐用的部件，这些部件在x、y和z平面上比目前的许多3D打印产品更坚韧。这些材料和加工技术将有助于推动添加剂制造进入大量但可定制的市场部门，以提高各行业的效率和生产率。由我们的可打印材料产生的打印部件将通过降低生产成本、提高产品性能和转移先进制造来进一步促进美国制造业。该项目专注于了解一种特殊类型的低粘度硫醇-烯树脂的界面化学和粘合现象，以生产一系列机械韧性材料，这些材料可通过立体光刻(SLA)进行3D打印。当前SLA方法的一个重要问题是，连续的印刷层不能充分结合在一起，导致韧性大幅下降，这是通过软、粘弹性和刚性材料的应力-应变响应来衡量的。我们的第二阶段研究探索了分子结构、反应性、树脂粘度和关键打印参数之间的权衡，以开发改进的材料，使打印部件能够在类似的打印速度和远低于100微米的特征尺寸下沿多个轴变形而比行业标准更坚韧。我们已经开发了一系列3D可打印材料，室温杨氏模数接近2兆帕、20兆帕、200兆帕或2 GPA。软材料和粘弹性材料在所有打印方向上的应变能力都远高于100%，包括垂直于打印层界面测量时。我们希望通过拟议的第二阶段SBIR努力，通过在我们的系统中加入适当的添加剂来控制颜色、保质期、美学、机械性能和与各种喷射技术的兼容性，从而进一步提高我们的聚合物的热机械性能。

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is making tough, 3D printed parts that can be directly manufactured through additive processes commercially available. Additive manufacturing has potential to revolutionize the way parts are produced by streamlining product design, production, and validation, which allows for low production costs and accelerated lead times. The penetration of additive technology into industrial processes has been greatly slowed by the current inability to 3D print parts of any stiffness with materials properties on par with traditionally manufactured parts. Particularly, 3D printed materials tend to tear or fracture more readily between successive printed layers. At Adaptive 3D Technologies, we have developed resins that produce tough, robust parts that are tougher than many current 3D printed products in the x, y and z planes by achieving covalent crosslinking across printed layers. These materials and processing techniques will help drive additive manufacturing into large volume, yet customizable, market sectors to increase efficiency and productivity across industries. The printed parts resulting from our printable materials will further U.S. manufacturing by lowering production costs, increasing product performance and reshoring advanced manufacturing. This project is focused on understanding interface chemistry and adhesion phenomena in a special class of low-viscosity, thiol-ene resins to produce a range of mechanically tough materials that are 3D printable via stereolithography (SLA). A significant problem with current SLA approaches is that successive printed layers do not adhere sufficiently together, leading to large reductions in toughness as measured by the stress-strain response in soft, viscoelastic and stiff materials. Our Phase II research explores the tradeoffs between molecular architecture, reactivity, resin viscosity, and key printing parameters to develop improved materials to enable tougher printed parts than industry standards along multiple axes of deformation at similar printing speeds and feature sizes well below 100 microns. We have developed a portfolio of 3D printable materials with room temperature Young's moduli near 2 MPa, 20 MPa, 200 MPa or 2 GPa. Soft and viscoelastic materials have strain capacities well above 100% in all print directions, including when measured perpendicular to print layer interfaces. We expect to further our polymers' thermomechanical properties through the proposed Phase II SBIR effort by incorporating proper additives into our systems to control color, shelf life, aesthetics, mechanical properties and compatibility with various jetting techniques.