Shari L. Kram

Biodegradation of an Epoxy-Based Thermoplastic Polyester, Poly(Hydroxy Ester Ether) in a Laboratory-Scale Compost System

An epoxy-based thermoplastic polyester, poly(hydroxy ester ether), was incubated under aerobic conditions in a laboratory-scale compost system for 168 days to evaluate its potential for biodegradation. Radiolabeled test polymer [uniformly 14C ring-labeled, poly(hydroxy ester ether)] was incorporated into a mature compost and a sludge-amended compost at a loading of ∼3 mg test polymer/g compost. 14C-Cellulose was used as the positive control and a biologically inhibited control reactor was used to assess abiotic degradation of the test polymer. Degradation of the test polymer was assessed by measuring the amount of 14C-CO2 from each of the test reactors. In addition, at selected time intervals subsamples of the compost were collected and serially extracted with water, methanol, and dimethylformamide to monitor degradation of the 14C-test polymer and provide a partial characterization of the degradation intermediates. Extensive degradation of 14C-poly(hydroxy ester ether) was observed in the test reactors with degradation half-life of the parent polymer (t1/2) of approximately 32 days. By the end of the study, only 2% of the total 14C activity in the test reactors was attributed to intact polymer, with most of the measurable 14C activity converted to either 14C-CO2 (26% of total 14C activity) or nonextractable products (accounting for ∼60% of the total activity). In contrast to the test reactors, only 3% of the 14C-poly(hydroxy ester ether) added to the biologically inhibited control reactor was mineralized to 14C-CO2. The results obtained from the microbially active and biologically inhibited compost systems indicate that the poly(hydroxy ester ether) polymer was degraded, at least in part, by a biologically mediated process.

Poly(hydroxy ether sulfonamides). A new class of epoxy‐based thermoplastics

Base-initiated polymerizations of N,′N-dimethyl-1,3-benzenedisulfonamide or other N,′N-dialkyldisulfonamides with various arylene-diglycidyl ethers afford a broad range of poly(hydroxy ether sulfonamides) (2). Polymers 2, which represent a new family of epoxy-based thermoplastics, are moldable, amorphous materials characterized by moderate Tg (58–127°C) and by good barrier to oxygen, reflected by oxygen transmission rates of 0.45–2.89 cc-mil/100 in2-atm (O2)-day at 234 °C and about 60% relative humidity. In addition to a discussion of how structural changes in the backbones of 2 influence their barrier properties, details of the synthesis, thermal analysis and mechanical evaluation of the polymers are described.

New class of brominated polymeric flame retardants for use in polystyrene foams

Flame retardant producers and end users are continually looking for more sustainable solutions through innovation in their customer offerings. Successful solutions need to satisfy a range of characteristics, from processing to technical and environmental performance, which sometimes conflict. This paper covers a new class of brominated polymeric flame retardants designed and developed by The Dow Chemical Company for use in polystyrene foam to meet existing fire and use requirements and have an improved environmental profile to meet regulatory guidelines. An overview of the environmental, health and safety performance of these new polymeric flame retardants will be presented along with preliminary performance data of their use in polystyrene foam.