Migration of different additives from polyethylen
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesisAlternative title
Migration av olika tillsatser från polyeten (Swedish)
Insecticidal polymer nets are used to combat malaria. It combines polyethylene fibers and two chemicals, deltamethrin (DM) and a synergist piperonyl butoxide (PBO) which increases efficacy of deltamethrin. The migration and evaporation of DM and PBO through polyethylene was studied in this report. The crystallinity and melting temperature of pristine DM, a prepared polymer compound and Vestergaard samples were characterized by differential scanning calorimetry (DSC). It was found that DM does not crystallize and remains liquid after cooling to room temperature. A small depression in melting temperature of the polymer was observed when samples were covered by a layer of DM. Rate constants and activation energies of evaporation were determined by thermogravimetry (TG) including pristine DM, PBO and their solution and also PE compound and Vestergaard samples. Higher rate constant for DM and PBO solution was observed in comparison with pure DM and PBO. The migration of DM and PBO from the polyethylene was studied in liquid water and air with different relative humidity (60 and 80%) at 80 ⁰C. Water caused degradation of the DM present in the material and generated product species containing nitro and amine groups. Besides, the degraded products including some undegraded DM formed a layer on the surface of the material (blooming). Liquid chromatography (HPLC) and infrared spectroscopy (IR) showed faster migration of the active species in liquid water than in air with 60 and 80% RH; (approximately 7 times for DM and 2 times for PBO). Some DM agglomerates was observed on the plate surface after exposure to air with 80 % RH.
Place, publisher, year, edition, pages
2011. , 40 p.
Deltamethrin, piperonyl butoxide, Irganox 1010, polyethylene, migration
IdentifiersURN: urn:nbn:se:kth:diva-33606OAI: oai:DiVA.org:kth-33606DiVA: diva2:416448
UppsokPhysics, Chemistry, Mathematics
Gedde, UlfNawaz, Sohail