Development of Green Chemistry for Syntheses of Polysaccharide-Based MaterialsEPA Grant Number: R826123
Title: Development of Green Chemistry for Syntheses of Polysaccharide-Based Materials
Investigators: Wang, Peng George , Chen, Yongsheng , Li, Jun , Xie, Wenhua
Current Investigators: Wang, Peng George
Institution: Wayne State University
EPA Project Officer: Richards, April
Project Period: November 1, 1997 through October 31, 2000 (Extended to October 31, 2001)
Project Amount: $180,000
RFA: Technology for a Sustainable Environment (1997) RFA Text | Recipients Lists
Research Category: Nanotechnology , Sustainability , Pollution Prevention/Sustainable Development
Description:Over the past century, we have exacted marvelous benefits from the advances in science. At the same time, we have paid an environmental price for this progress. The annual level of toxic waste from the chemical industry in the US is projected to grow to more than 500 million tons by the year 2000 and will cost more than $40 billion for proper disposal. We have now come face to face with an unprecedented challenge: environmental protection and sustainable economic growth. Since non-renewable raw materials such as petroleum, natural gas and coal for chemical and pharmaceutical industries are disappearing fast with increasing population pressure, development of environmentally friendly catalysis/biocatalysis processes and switch from the dependence on petroleum to renewable resources (mainly from agricultural feedstocks such as cellulose and starch) are strategic steps to face this challenge. This proposed research program uses such renewable natural polysaccharides as platform, and uses novel lanthanide catalysts as novel synthetic tools to develop environmentally friendly chemistry for synthesis of novel polysaccharide-based materials.
Our recent work has demonstrated that lanthanide trifluoromethanesulfonate (triflate) complexes can serve as stable Lewis acids under nearly neutral conditions in protic solvents, such as water or alcohols to replace many traditional reaction systems which are either conducted in strong acidic conditions or in environmentally less-friendly solvents. We call this lanthanide-catalyzed reaction in protic solvents LanTech. We propose to use LanTech to carry out two research projects during the supported period:
(1) Develop lanthanide catalyzed synthesis of cellulose-ethers to replace current industrial processes. Cellulose ethers cover a broad spectrum of polymeric materials with a variety of industrial applications. The industrial production of cellulose ethers based on alkalization with aqueous sodium hydroxide generates pollution and large amounts of wastes, and is also corrosive and energy consuming. We propose to develop the LanTech process to replace the existing process. The research will involve a systematic screening of different structures of reactants, different lanthanide catalysts, the effect of solvents, the interplay between ring reaction conditions and cost estimation on a small scale production. This project will set the first example for converting environmentally benign organic reactions into practical industrial uses.
(2) Develop lanthanide-catalyzed polymerization technology to graft polyesters onto polysaccharides. We propose to use lanthanide catalysts to conduct ring-opening polymerization of L-lactide in the presence of polysaccharides to produce polyester-polysaccharide co-polymers. We envision that this copolymer will combine the hydrophilic properties of saccharide and hydrophobic properties of poly(lactic acid) together and make new types of biocompatible and biodegradable materials.
Our long term goal is to continue to develop novel green chemistry and use such technology to develop environmentally friendly processes to produce novel materials.