SusChEM: Development of Polymer-grafted Lignin Superplasticizers

CBET-1510600PI：沃什伯恩，Newell R.水力水泥是全球二氧化碳排放到大气中的主要贡献者。低二氧化碳水泥是可用的，但没有得到广泛应用，因为它们很难加工。该项目将开发一种新型高效减水剂，可以添加到低二氧化碳水硬性水泥中，以改善水泥的加工性能，同时减少二氧化碳排放。这种新型高效减水剂将使用PI开发的一种工艺来配制，在该工艺中，合成聚合物接枝到木质素上，木质素是一种从植物中提取的生物聚合物。使用新型高效减水剂可以减少用水量并改善低二氧化碳水泥的性能，这两者都将减少施工对环境的影响。该项目将检验这样一个假设，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性能的化学-结构-性能关系，以调节水泥悬浮液的流变性。该项目将比较木质素的化学成分和接枝变量，以确定它们如何影响水悬浮性能，研究聚合物接枝木素在水泥颗粒上的吸附作为接枝变量和电荷的函数，并建立聚合物接枝木素对低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.