SusChEM: Development of Polymer-grafted Lignin Superplasticizers

水力水泥是向大气中排放二氧化碳的主要贡献者。低二氧化碳水泥是可用的，但没有广泛使用，因为它们很难加工。本项目将开发一种新型高效减水剂，可添加到低碳二氧化碳水力水泥中，以改善水泥的加工特性，同时减少二氧化碳的排放。新型高效减水剂的配方将采用PI开发的一种工艺，将合成聚合物接枝到木质素上，木质素是一种源自植物的生物聚合物。使用新型高效减水剂可以减少用水量，提高低碳水泥的性能，从而减少施工对环境的影响。该项目将测试一个假设，即木质素化学的复杂性将使高效减水剂能够吸附在广泛的低碳二氧化碳水泥上。该项目将确定控制聚合物接枝木质素分散剂特性的化学-结构-性能关系，以调节胶凝悬浮液的流变性能。该项目将比较木质素的化学性质和接枝变量，以确定它们如何影响水悬浮性能，研究聚合物接枝木质素在水泥颗粒上的吸附作为接枝变量和电荷的函数，并确定聚合物接枝木质素对二氧化碳水泥水化和高强度水泥相形成的影响。

CBET - 1510600PI: Washburn, Newell R.Hydraulic cement is a major contributor to global carbon dioxide emissions into the atmosphere. Low carbon dioxide cements are available but not widely used, because they are difficult to process. This project will develop a new superplasticizer that can be added to low-carbon dioxide hydraulic cement to improve the cement's processing characteristics while reducing carbon dioxide emissions. The new superplasticizer will be formulated using a process developed by the PI in which synthetic polymers are grafted onto lignin, a biopolymer derived from plants. Use of the new superplasticizer could reduce water use and improve the performance of low-carbon dioxide cements, both of which would reduce the environmental impact of construction.The project will test the hypothesis that the complexity of lignin chemistry will enable the superplasticizer to adsorb onto a broad range of low-carbon dioxide cements. The project will identify chemistry-structure-property relationships governing the dispersant properties of polymer-grafted lignin in tuning the rheological properties of cementitious suspensions. The project will compare lignin chemistries and grafting variables to determine how they affect aqueous suspension properties, examine the adsorption of polymer-grafted lignin on cement particles as a function of grafting variables and charge, and establish effects of polymer-grafted lignin on the hydration of low-carbon dioxide cements and the formation of high-strength cement phases.