Advanced non-invasive fluorescence spectroscopy and imaging for mapping photo-oxidative degradation in acrylonitrile–butadiene–styrene: A study of model samples and of an object from the 1960s

This article describes the restoration of a glass bowl from the 16th-17thcentury by creating its three-dimensional (3D)model. The final purpose is to work with this model in order to avoid damaging situations that are associated with the manipulation of fragile objects. The gap areas, those corresponding to the missing fragments not found in the excavation, were carried out by constructing digital implants. A restricted area of the 3D model has been duplicated in order to accommodate it to confined intervals of the gap. The final implants were printed with acrylonitrile butadiene styrene (ABS) filament. These implants replace the lost areas and give stability back to the item by recovering the original morphology. The result can be compared with the outcome obtained by a traditional process, but differs due to the fact that requires minimum manipulation of the item, so it can contribute to preserve and safeguard the restored object. This is a non-invasive method which is offered as an alternative treatment, where the archaeological object is replaced by its virtual model in the steps of the process after 3D data acquisition. Significant differences have not been found in the 3D printing results obtained with the two types of filaments tested (white and clear).

Download Full-text

GM-Improved Antiaging Effect of Acrylonitrile Butadiene Styrene in Different Thermal Environments

Polymers ◽

10.3390/polym12010046 ◽

2019 ◽

Vol 12 (1) ◽

pp. 46

Author(s):

Yuchao Wang ◽

Ming Chen ◽

Miaoyu Lan ◽

Zhi Li ◽

Shulai Lu ◽

...

Keyword(s):

Thermal Stability ◽

Free Radicals ◽

Oxidation Process ◽

Oxidative Degradation ◽

Acrylonitrile Butadiene Styrene ◽

Active Species ◽

Tert Butyl ◽

Thermal Environments ◽

Thermal Stability Of ◽

Butadiene Styrene

A stabilizer called 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate (GM) was mixed in acrylonitrile butadiene styrene (ABS) with the same amount of 9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (DSPDP), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (Irganox 1076) and tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate (Irganox 3114) to investigate the influence of additives on the antiaging effect of ABS in oven aging or repeated extrusion aging. It was found that the ABS doped with the GM stabilizer showed a better yellowing resistance and thermal stability than the ABS doped with other antioxidants. Owing to the fact that the stabilizer can act on the free radicals before it has been peroxidized, it could trap the free radicals as a consequence of directly blocking the oxidation process of the active species, thus solving the problem of oxidative degradation of the materials from the source. This work provides guidance for improving thermal stability of ABS, indicating a promising potential for industrial application.

Download Full-text