SBIR Phase I: Smart Two-Way Shape Memory Polymer Based Sealant

这个小型企业创新研究第一阶段项目旨在提供一种价格合理的密封胶，用于密封混凝土路面、桥面等的伸缩缝和裂缝。在交通基础设施中，伸缩缝是故意建造的，以便在温度上升时允许结构元件因线性热膨胀而移动。此外，裂缝也是路面常见的破坏形式。如果密封不当，渗水会损坏表层和下面的层，被困的碎屑会导致混凝土墙破裂。因此，对裂缝和接缝进行密封是维护或延长结构使用寿命的常见做法。各种类型的密封胶已被使用，年市场价值约为61亿美元。不幸的是，许多密封剂不能很好地密封裂缝和接缝，和/或持续时间较长，需要频繁更换或重新密封。在这个项目中，将开发一种智能密封胶，这种密封胶在冷却时会膨胀，在加热时会收缩，这种密封胶在温度上与混凝土相反，以抵消连接的结构元件的温度移动。该项目的智力价值在于智能密封胶技术的可行性。接缝失效的主要原因是大多数密封胶的性能类似于混凝土，即它们在冷却时收缩，在加热时膨胀。这种热行为与密封胶的要求相反。本项目的目标是设计、合成、表征和评价一种经济高效的双向形状记忆聚合物密封剂，用于密封混凝土路面或桥面的伸缩缝或裂缝，这些裂缝在冷却时会膨胀，在加热时会收缩。它将具有所需的机械性能和耐用性，以在反复的交通负荷和室外环境中生存下来。该项目的成功不仅可以对交通基础设施产生有益的影响，还可以对其他结构产生有益的影响，如车道、停车场、水坝、港口、建筑物、游泳池等。

This Small Business Innovation Research Phase I project aims to provide an affordable sealant for sealing expansion joints and cracks in concrete pavement, bridge deck, etc. In transportation infrastructure, expansion joints are intentionally constructed in order to allow movement of the structural elements due to linear thermal expansion when temperature rises. In addition, cracks are a common failure mode in pavement. If they are not properly sealed, water penetration will damage the surface layer and the layers beneath, and entrapped debris will cause rupture of the concrete wall. Therefore, sealing cracks and joints is a common practice to maintain or extend the structure service life. Various types of sealants have been used with an annual market value about $6.1 billion. Unfortunately, many sealants cannot properly seal cracks and joints, and/or last long, requiring frequent replacement or resealing. In this project, a smart sealant that expands upon cooling and contracts upon heating, which is thermally opposite to concrete, will be developed to counteract thermal movement of the joined structural elements. The intellectual merit of this project lies in the feasibility of a smart sealant technology. The primary reason for joint failure is that most sealants behave similar to concrete, i.e., they contract upon cooling and expand upon heating. This thermal behavior is contrary to the requirement for sealants. The objective of this project is to design, synthesize, characterize, and evaluate a cost-effective two-way shape memory polymer based sealant for sealing expansion joints or cracks in concrete pavement or bridge deck, which will expand upon cooling and contract upon heating. It will have the required mechanical properties and durability to survive the repeated traffic load and outdoor environment. The success of the project can have beneficial impact not only on the transportation infrastructure but also other structures such as driveways, parking lots, dams, harbors, buildings, swimming pools, etc.