Green Chemistry Yamini Karandikar CBE 555

12 Principles (EPA) Prevent waste Maximize atom economy Design less hazardous chemical syntheses Design safer chemicals and products Use safer solvents and reaction conditions Increase energy efficiency

12 Principles (EPA) continued Use renewable feedstocks Avoid chemical derivatives Use catalysts, not stoichiometric reagents Design chemicals and products to degrade after use Analyze in real time to prevent pollution Minimize the potential for accidents

Green Cleaning Products Alkyl polyglucoside (APG) vs. Alcohol Ethoxylates (AE) Both are amphipathic non-ionic surfactants Uses: Detergent, surface cleaning, personal hygiene, etc Dgradation behavior of linear alkylbenzenesulfonates (LASs) degraded after 22 days @5mg/L. 1.2 life =5 days, APG 1.2 life=18 hrs Shampoo, Bubble bath, Cleaning lotion, Skin care products, Dishwashing detergents Cosmetic emulsifiers, Hard surface cleaners, Industrial cleaners, Adjuvant for textile

APG Advertised as… Non-toxic, mild to skin Safe for environment and consumers Soluble in water No VOCs Obtained from renewable raw materials

Alkyl Polyglucoside-Synthesis Coconut/corn instead of petroleum derivatives (renewable)

APG-Synthesis

APG Degradation possible pathways

Degradation in river water Glucosides are naturally found in many plants Hydrolyzed to form glucose Half life of .75 days

Alcohol Ethoxylate-Synthesis ROH + n C2H4O → R(OC2H4)nOH Alcohol is treated with ethylene oxide and KOH (catalyst) Alkyl chain and alcohol form hydrophobic part Ethylene oxide units for hydrophilic part Ethylene oxide is hazardous flammable, carcinogenic, mutagenic, irritating, and anaesthetic gas alcohol ethoxylates are derived from primary alcohols and ethylene oxide via a base catalyzed reaction of potassium or sodium hydroxide followed by treatment with a neutralizing agent such as acetic or phosphoric acid long aliphatic alkyl chain and an alcohol, thus forming the hydrophobic portion of the molecule that is connected to a chain with several units of ethylene oxide (EO), which is characterized as the hydrophilic fraction In industrial ethoxylation, an alcohol is treated with ethylene oxide and potassium hydroxide (KOH), which serves as a catalyst. The reactor is pressurised with nitrogenand heated to about 150 °C. Typically 5-10 units of ethylene oxide are added to each alcohol:  

Alcohol Ethoxylate-Degradation Half-life of 1.6 days Dependent on degree of branching and chain length

Comparision Water soluble No VOC Safe product Half life of ~0.75 days Alkyl Polyglucoside Alcohol Ethoxylate Water soluble No VOC Safe product Half life of ~0.75 days Less hazardous chemical syntheses Uses renewable feedstock Water soluble No VOC Safe product Half life of ~1.6 days Synthesis involves ethylene oxide Reactants made from alkenes, which are petrochemical derivatives

Conclusions Alkyl polyglucoside is safer to manufacture How dangerous is ethylene oxide? Is this diluted prior to industrial use? Alkyl polyglucoside is synthesized from renewable feedstock Both are very biodegradable and safe for consumers