DEVELOPMENT OF NANOSTRUCTURED COATINGS FOR THE PROTECTION OF TEXTILES AND PAPER

Subjects

Subjects :

thus ensuring a good breathability and vapour permeability of treated samples. Slight variations in the tensile strength measurements were observed
no notable variations were observed by M.O. and colorimetric measurements on specimens treated with PDMS or fluoro-acrylic polymer with nanoparticle concentrations lower than 0.125%. On the contrary
the comparison between treated and untreated specimens after ageing indicates that untreated samples change colour. The treatment is therefore effective in reducing surface wettability
methanol as well as less toxic acetone
water-repellency (by contact angle measurement)
Textiles and paper are cellulosic materials prone to severe decay if exposed to an aggressive environment and more importantly when exposed to water in all its forms. The purpose of this research is to develop water-repellent treatments based on environmentally approved fluoro-acrylic co-polymer nanosilica composites, suitable for the conservation of paper and textiles. The products and treatments must fulfil the requirements of physico chemical and aesthetical compatibility as only slight changes to hygroscopic behavior and appearance are allowed. Different formulations were tested by diluting a commercial waterborne fluoro -acrylic copolymer at different concentrations (2%, 3% 4%, 5% by weight), and admixing it with hydrophobic silica nanoparticles (functionalised with 1,1,1 -trimethyl-N-(trimethylsilyl)-silanamine,0.125% and 0.250% by weight. In order to reduce surface tension for better impregnation, methanol as well as less toxic acetone, and ethanol were tested. The resultant treatment performances have been also compared to treatments made by polymethyl methacrylate (PMMA) and polydimethylsiloxane (PDMS) polymers. The different products were sprayed onto 5 types of canvas (also with preparation layer), books from the 1920’s and common white paper, then cured at T=60°C for two hours. Visual appearance (determined by optical microscopy M.O. and CIE_L*a*b* colours variations), water-repellency (by contact angle measurement), vapour permeability, hygroscopic and mechanical behaviour were assessed on specimens before and after one month of artificial ageing under UV lamps (13.6W irradiated between 315 and 400nm and 3.0W irradiated between 280 and 315nm). Microstructure and surface composition of the treated specimens were investigated by ATR-FTIR and SEM-EDX. High contact angle values (130°-150°) were measured on treated surfaces highlighting the fact that fluoro-acrylic, PDMS and PMMA formulations were effective in reducing the liquid water/surfaces interaction. Moreover, no notable variations were observed by M.O. and colorimetric measurements on specimens treated with PDMS or fluoro-acrylic polymer with nanoparticle concentrations lower than 0.125%. On the contrary, the use of PMMA and fluoro-acrylic polymer with 0.250% nanoparticles resulted in a glossy surface or in a visible whitening of paper and textiles, respectively. SEM analysis showed that fluoro-acrylic products did not create a continuous vapour-blocking film, but they covered the single fibres, thus ensuring a good breathability and vapour permeability of treated samples. Slight variations in the tensile strength measurements were observed, in particular for paper. Artificial ageing with solar lamps did not affect the fluoro-acrylic based formulations. On the contrary, the comparison between treated and untreated specimens after ageing indicates that untreated samples change colour. The treatment is therefore effective in reducing surface wettability, maintaining similar permeability and appearance and protecting the surface from oxidizing action of UV–rays. Further testing is underway to evaluate long -term behaviour and longer ageing times
Textiles and paper are cellulosic materials prone to severe decay if exposed to an aggressive environment and more importantly when exposed to water in all its forms. The purpose of this research is to develop water-repellent treatments based on environmentally approved fluoro-acrylic co-polymer nanosilica composites
but they covered the single fibres
0.125% and 0.250% by weight. In order to reduce surface tension for better impregnation
books from the 1920’s and common white paper
and admixing it with hydrophobic silica nanoparticles (functionalised with 1
then cured at T=60°C for two hours. Visual appearance (determined by optical microscopy M.O. and CIE_L*a*b* colours variations)
3% 4%
1 -trimethyl-N-(trimethylsilyl)-silanamine
PDMS and PMMA formulations were effective in reducing the liquid water/surfaces interaction. Moreover
vapour permeability
5% by weight)
the use of PMMA and fluoro-acrylic polymer with 0.250% nanoparticles resulted in a glossy surface or in a visible whitening of paper and textiles
hygroscopic and mechanical behaviour were assessed on specimens before and after one month of artificial ageing under UV lamps (13.6W irradiated between 315 and 400nm and 3.0W irradiated between 280 and 315nm). Microstructure and surface composition of the treated specimens were investigated by ATR-FTIR and SEM-EDX. High contact angle values (130°-150°) were measured on treated surfaces highlighting the fact that fluoro-acrylic
Settore CHIM/12 - Chimica dell'Ambiente e dei Beni Culturali
suitable for the conservation of paper and textiles. The products and treatments must fulfil the requirements of physico chemical and aesthetical compatibility as only slight changes to hygroscopic behavior and appearance are allowed. Different formulations were tested by diluting a commercial waterborne fluoro -acrylic copolymer at different concentrations (2%
and ethanol were tested. The resultant treatment performances have been also compared to treatments made by polymethyl methacrylate (PMMA) and polydimethylsiloxane (PDMS) polymers. The different products were sprayed onto 5 types of canvas (also with preparation layer)
respectively. SEM analysis showed that fluoro-acrylic products did not create a continuous vapour-blocking film
in particular for paper. Artificial ageing with solar lamps did not affect the fluoro-acrylic based formulations. On the contrary
maintaining similar permeability and appearance and protecting the surface from oxidizing action of UV–rays. Further testing is underway to evaluate long -term behaviour and longer ageing times

Details

Language :

English

Database :

OpenAIRE

Accession number :

edsair.od......3655..eb54ed96f4ced75d73ceca2230dcfd0f