14-Hydroxycaryophyllene 4,5-oxide — A new sesquiterpene fromBetula pubescens
A new sesquiterpene — 14-hydroxycaryophyllene 4,5-oxide — has been isolated from the unsaponifiable part of an ethereal extract of the leaves ofBetula pubescens, and its structure has been established on the basis of chemical and spectral characteristics.
Essential oils from the buds of Betula spp. growing in Turkey
The essential oils from buds of Betula browicziana A. Guner, B. litwinowii Doluch., B. medwediewii Regel, B. pendula Roth and B. recurvata V. Vassil. (Betulaceae) were either hydrodistilled using a Clevenger-type apparatus or were subjected to Likens-Nickerson simultaneous distillation-extraction (SDE) when the plant material amounts were insufficient. The resulting bud essential oils were analysed by GC-MS. Main components were detected as 14-hydroxy-β-caryophyllene (1) and 14-hydroxy-4,5-dihydro-β-caryophyllene (2) in all the oil samples.
Enhancement of surface properties on Low Density Polyethylene packaging films using various fluorination routes
Nowadays, packaging market deployment requires an important attention. Influence of treatment with molecular (F2) or atomic (Fradical dot) fluorine on properties of Low Density Polyethylene (LDPE) films was investigated. The films were treated using direct fluorination conditions with F2 or a specific reagent XeF2, which releases atomic fluorine Fradical dot. Changes of LDPE chemical composition were investigated by FTIR and solid state NMR. Surface morphology was studied by several microscopy techniques (SEM and AFM). Finally to further characterize film properties after treatments, surface energy measurements and electron paramagnetic resonance (EPR) analyses were also carried out. An upper fluorinated layer, which contains mainly high amount of single bondCF2single bond, was formed during the direct fluorination conditions (F2). For the process performed with XeF2, specific groups single bondCHFsingle bond were detected not only on the polymer surface but also in the bulk. The final CHF/CF2 ratio depended on the fluorination route. Treatment with Fradical dot (originated from XeF2 decomposition) resulted in single bondCHFsingle bond groups in bulk prevailing formation whereas F2 formed mainly single bondCF2single bond groups. Regardless to the reactive species, radicals (dangling bonds) appeared during the fluorination and reacted with oxygen during the exposition to air after the treatment. Such a process resulted in oxygenated polar groups formation and consequently in the surface energy increase.