Poten­tially safer, green­er altern­at­ive to BPA could come from paper­mak­ing waste

“Approx­im­ately 3.5 mil­lion tons of BPA are pro­duced annu­ally world­wide,” said Kaleigh Reno, a gradu­ate stu­dent who presen­ted the report. BPA is the com­pon­ent that gives shat­ter-proof plastic eye­wear and sports equip­ment their strength. Addi­tion­ally, BPA is used in high-per­form­ance glues, in the lin­ing of cans and in receipt paper, she explained. The down­side is that bisphenol‑A, as it’s called, can mim­ic the hor­mone estro­gen, poten­tially affect­ing the body and brain. Some experts have sug­ges­ted that it’s unsafe for young chil­dren and preg­nant women to con­sume. To find a safer, more envir­on­ment­ally friendly altern­at­ive, Reno and her advisor, Richard Wool, Ph.D., who are at the Uni­ver­sity of Delaware, turned to lignin. They note that paper­mak­ing and oth­er wood-pulp­ing pro­cesses pro­duce 70 mil­lion tons of lignin byproduct each year, 98 per­cent of which is incin­er­ated to gen­er­ate small amounts of energy. Reno has developed a pro­cess that instead con­verts lignin frag­ments into a com­pound called bisguaiacol‑F (BGF), which has a sim­il­ar shape to BPA. She and Wool pre­dict it will act like BPA, as well. ​“We expect to show that BGF has BPA-like prop­er­ties with­in a year,” said Wool, with a product ready for the mar­ket two to five years later. Reno is con­fid­ent that BGF will be a safe stand-in for BPA. ​“We know the molecu­lar struc­ture of BPA plays a large role in dis­rupt­ing our nat­ur­al hor­mones, spe­cific­ally estro­gen,” she said. ​“We used this know­ledge in design­ing BGF such that it is incap­able of inter­fer­ing with hor­mones but retains the desir­able thermal and mech­an­ic­al prop­er­ties of BPA.” The research­ers also used U.S. Envir­on­ment­al Pro­tec­tion Agency soft­ware to eval­u­ate the molecule, determ­in­ing it should be less tox­ic than BPA. And because BGF is made from an exist­ing waste product, Reno believes it will be a viable altern­at­ive eco­nom­ic­ally and envir­on­ment­ally. BPA is man­u­fac­tured from com­pounds found in oil, a fossil fuel, while BGF’s feed­stock, lignin, comes from trees, a renew­able resource. The research­ers chose BGF based on their unique ​“Twink­ling Fractal The­ory,” which Wool explains can pre­dict mech­an­ic­al and thermal prop­er­ties. ​“This approach con­sid­er­ably sim­pli­fies the design of new biobased mater­i­als since we can pre­de­ter­mine prop­er­ties and screen for tox­icity for a broad range of poten­tial com­pounds from renew­able resources such as lignin and plant oils,” he says. The research­ers acknow­ledge fund­ing from the U.S. Army Research Labor­at­ory via a DoD-SER­DP grant.

About the ACS

The Amer­ic­an Chem­ic­al Soci­ety is a non­profit organ­iz­a­tion chartered by the U.S. Con­gress. With more than 161,000 mem­bers, ACS is the world’s largest sci­entif­ic soci­ety and a glob­al lead­er in provid­ing access to chem­istry-related research through its mul­tiple data­bases, peer-reviewed journ­als and sci­entif­ic con­fer­ences. Its main offices are in Wash­ing­ton, D.C., and Colum­bus, Ohio. Title: (at the 247^th Nation­al Meet­ing & Expos­i­tion) Tack­ling tox­icity: Design­ing a BPA altern­at­ive from lignin
Abstract: Over five mil­lion met­ric tons of bisphen­ol A (BPA) are pro­duced annu­ally for the syn­thes­is of plastics, such as epoxy res­ins, vinyl ester res­ins, and polycar­bon­ates. BPA can mim­ic estro­gen in vivo and can inter­fere with early repro­duct­ive devel­op­ment and cause irre­vers­ible phys­ic­al changes. There­fore, design­ing sus­tain­ably sourced, less tox­ic BPA altern­at­ives is desir­able. We syn­thes­ized bis­guai­ac­ol F (BGF) as a poten­tial BPA altern­at­ive from two lignin mod­el com­pounds, vanillyl alco­hol and guai­ac­ol. Lignin is a prom­ising feed­stock for aro­mat­ic monomers as the paper and pulp­ing industry pro­duces 70 mil­lion tons a year as a waste product and can be depoly­mer­ized into use­ful aro­mat­ic com­pounds. Sim­il­ar to the indus­tri­al syn­thes­is of BPA, the con­dens­a­tion reac­tion between vanillyl alco­hol and guai­ac­ol pro­duce two regioi­somers. Selectiv­ity between regioi­somers and oth­er byproducts can be tuned by chan­ging reac­tion con­di­tions such as water con­tent, acid­ic ion exchange res­in pro­ton exchange capa­city, and reac­tion time. DSC was used to determ­ine the effect of regioi­somer con­tent on the thermal beha­vi­or of BGF. Poly­es­ters con­tain­ing BGA and BGF were com­pared using ther­mo­mech­an­ic­al ana­lyses (TGA, and DSC). Source: Amer­ic­an Chem­ic­al Soci­ety (ACS)