Dagmar Měřínská

PVB Sheet Recycling and Degradation

Increasing growth of raw material prices, environmental aspects and still growing landfill fees bring about the increasing interest encountered with the plastics waste recycling. Globally, the problem has been solved for the common plastics such as polyolefins, poly(ethylene terephtalate) and poly(styrene). Though extensively used for the glass lamination, poly(vinyl butyral) (PVB) does not belong to this group. It is generally known that during the glass lamination process, large volume of PVB trim is formed.

EVA copolymer/clay nanocomposite films processing conditions and the effect on barrier properties

Nanocomposite materials with layered clay used as nanofiller and copolymer ethylene and vinyl acetate matrix (EVA, the content of VA component l9 wt. % and 5% wt.) were prepared by compounding the individual components in KO Buss kneader. The MMT Na+ and four types of commercial products such as Nanofil N 5 and N3000, Cloisite 93A and 30B were used as nanofillers. The quantity of all the above-mentioned nanofillers was 3 and 5 wt. % in relation to the content of montmorillonite. The aim was to evaluate the influence of VA content on resulting nanocomposite properties.The morphology of nanocomposite EVA/clay samples was examined by means of transmission electronic microscopy TEM. Furthermore, mechanical and especially barrier properties were observed.Despite the fact that the XRD and microscopy results have revealed that complete exfoliation did not take place in any case, mechanic properties as well as the permeability measurements show that 3% concentration of clay was enough to achieve the improvement o...

DESCRIPTION OF DEGRADATION INFLUENCE ON THE PLASTICIZED PVB DURING ITS RE‐WORKING BY KNEADING

PVB sheet (type Butacite 3GO) with polymer chains containing butyraldehyde, hydroxyl‐ and small amount of acetate groups, was tested. These sheets were highly plasticized, with the content of plasticizer 28%. Studied material was tested at different kneading conditions; especially the influence of temperature, oxygen, mechanical energy and created heat of dissipation was studied.PVB sheet was kneaded at their usual humidity cca 0.5%. Because PVB in known as the material with high hydroscopity, next tests were done on PVB sheets macerated in water. By this operation the humidity of sheets increases to the content 8.0%. High humidity influenced all observed properties. Simultaneously, samples of PVB sheets re‐worked by calendaring and pressing. At the calendaring the sheets were thermally stressed. The calendaring represents shear stress at low temperature. The degradation was evaluated as the change of optical properties, like the light transmittance through the re‐worked material, created haze and yellowi...