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The need for alternative cultivation methods is urgent for regions of the world where cultivable land is scarce: underwater areas are unexploited and vast. Nemo’s Garden® Project aims at creating a green and alternative agriculture system: its biospheres are underwater greenhouses, developed for areas where plants growth is difficult in terrestrial conditions, due to climate change. Basil was chosen as model plant to study its phytochemical, physiological, and micromorphological parameters, in comparison with the same plants grown in terrestrial conditions in the Sanremo Research Centre for Vegetable and Ornamental Crops (CREA-Centro di Ricerca Orticoltura e Florovivaismo) greenhouse. While the micromorphological analyses showed no detectable differences between control and biospheres samples, the phytochemical investigations evidenced a switch of the essential oil chemotype from methyl eugenol/linalool to methyl eugenol, respectively. The headspaces were also different: sesquiterpenes dominated the biospheres samples, whereas oxygenated monoterpenes accounted for half the control sample emission. Differences also emerged in the physiological investigation: total chlorophyll, total carotenoids and total polyphenols were present in higher amounts in the biospheres samples, with a 31.52% and 13.3% increase in the antioxidant activity and polyphenols content, respectively. Basil was well adapted in the biosphere environment, whose influence should be studied in different species to assess the viability of an industrial scale-up of the Nemo’s Garden®.

To verify the effect of hydrogen bonding on the polymer mixing, blends of poly(vinyl methyl ether) (PVME) and poly(methyl methacrylate) (PMMA) with poly(4-hydroxy styrene) (PHS), respectively, have been prepared. The effect of hydrogen bond strength on the enthalpy of mixing, ΔHM, was investigated by microcalorimetric measurements and FTIR spectroscopy. Infrared analysis allowed to measure the amount of hydrogen bonding by a curve fitting procedure in PHS/PMMA blends, looking to the change in the characteristic bands of carbonyl group of PMMA. In the case of PHS/PMVE, the hydroxyl-stretching region has been investigated to have only a qualitative estimation of hydrogen bonding. For both PHS/PMVE and PHS/PMMA systems, the measured exothermic (negative) ΔHM decreases with the increase in the PHS content, indicating that the presence of strong specific intermolecular interactions, such as hydrogen bonding, favours the polymer blending.

After the positive experiences collected in the period 2012–2015, Nemo's Garden Project has been started again in 2016 trying to improve the knowledge not only about the engineering and installation underwater of structures dedicated to the growth of vegetables for human consumption, but also about the physical-chemical-biological processes occurring during the plants development under sea.

In this work, a study concerning the composition of Italian papers from the seventeenth to the twentieth centuries was carried out using energy dispersive X-ray fluorescence spectrometry (EDXRF), X-ray diffraction (XRD), and scanning electron microscopy coupled to energy dispersive spectrometry (SEM-EDS). The analyzed samples consisted of papers employed for drawing, writing, printing, and absorbance. Observations carried out by SEM magnified the typical paper morphology. EDXRF in combination with XRD and SEM-EDS allowed the determination of calcite, gypsum, kaolin, talc, magnesite, and dolomite, used as fillers in the production of the papers studied herein. The inks present in the handwritten and printed papers, investigated by SEM-EDS and μ-EDXRF, were synthetic, Fe based, and iron gall inks.

In this article, the miscibility of poly(e-caprolactone) (PCL) with poly(styrene-co-acrylonitrile) (SAN) containing 25 wt % of acrylonitrile is studied from both a qualitative and a quantitative point of view. The evidences coming from thermal analysis (differential scanning calorimetry) demonstrate that PCL and SAN are miscible in the whole range of composition. The Flory interaction parameter χ1,2 was calculated by the Patterson approximation and the melting point depression of the crystalline phase in the blends; in both cases, negative values of χ1,2 were found, confirming that the system is miscible. The interaction parameter evaluated within the framework of the mean field theory demonstrates that the miscibility of PCL/SAN blends is due to the repulsive interaction between the styrene and acrylonitrile segments in SAN. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010

Grafting polymerization of acrylic monomers onto cellulose chains possesses a great potential for tailoring the properties of cellulose-based materials. In this article, some results concerning the grafting polymerization of ethyl acrylate/methyl methacrylate (EA/MMA) 75/25 wt % on cotton fabrics are reported. The effectiveness of the grafting process as a method for the mechanical reinforcement of cotton without any modification of its handle is discussed. In addition, SEM observations were carried out to check the morphological modification occurring on cotton after the grafting reaction. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

BACKGROUND: The miscibility of poly(vinyl acetate) (PVAc) with a series of polyacrylates, namely poly(methyl acrylate) (PMA), poly(ethyl acrylate) (PEA) and poly(butyl acrylate) (PBA), with ester chains of varying bulkiness was studied from both qualitative and quantitative points of view. RESULTS: The evidence from thermal (differential scanning calorimetry) and Fourier transform infrared analyses demonstrates that the miscibility of PVAc with the polyacrylates is rapidly reduced on increasing the bulkiness of their ester chains. Miscibility is quantitatively discussed in the framework of the corresponding states theory applying the approximate Patterson form. For this reason the characteristic values of volume, temperature and pressure were preliminarily evaluated both experimentally, through dilatometric measurements, and by calculations. At the same time, calorimetric measurements allowed the evaluation of the enthalpies of mixing of the components. CONCLUSION: The conclusions reached with this approach are that polar interactions are active among the repeat units of the blend components, but the intensities of these forces are progressively reduced by the shielding of the apolar groups of the polyacrylates. The steric hindrance of the hydrocarbon groups shields the interactions of the polar groups of PVAc with the COOR moieties of the acrylates, so that the miscibility progressively decreases from PMA to PEA to PBA. Copyright © 2009 Society of Chemical Industry

Some polyester and polycarbonate-based waterborne polyurethanes (WPU) were characterised by means of several techniques, to correlate the morphology with their structures and properties. The morphological analysis carried out by transmission electron microscopy on thin sections showed that the selected polyurethanes, after purification, exhibit a nanostructured phase separation between hard and soft domains. The presence of hydrogen bonding and the hard/soft ratio were evaluated by FT IR and NMR spectroscopy. Both the thermal and the dynamic mechanical analysis allowed the polymers microstructure to be correlated with the polymer properties; two glass transition temperatures were determined, corresponding to the hard and soft domains respectively.

Grafting polymerisation of acrylic monomers onto cellulose chains represents a useful method of restoration for both artificially and naturally aged paper-based materials. In this paper, some results concerning the grafting polymerisation of ethyl acrylate/methyl methacrylate 75/25 wt.% copolymer onto several paper grades are reported, highlighting how the presence of fillers in the raw materials reduced the grafting yields. The consolidating and protective effects have been investigated by evaluating the mechanical properties and the wetting behaviour of the grafted samples, and comparing them with the original and aged substrates.

In this article, the Lattice Cluster Theory developed by Freed and coworkers is applied to the poly(styrene)/poly(vinyl methylether) system by measuring the enthalpy and the volume variation associated with the mixing of the two homopolymers. It comes out that the chains architectures previously chosen for the two macromolecules based on the phase diagram and of the partition function developed by the theory correctly predicts the sign of both ΔHM and ΔVM. The foreseen trends as function of mixture composition fit the experimental data only for ΔVM; ΔHM is higher than predicted, asymmetrical and independent on the chain lengths of the components. The conclusion is that the theory needs some final touches in order to obtain a better agreement with experiments. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 791–797, 2008

A complete multianalytical study of a hand-coloured map from the seventeenth century is presented. The pigments atacamite, massicot, minium, gypsum, carbon black and vermilion were determined by means of XRF and Raman spectroscopy. The state of conservation of the cellulosic support was monitored by means of unilateral NMR. The analysis was nondestructive and noninvasive, and thus several spectra were collected from the same areas, yielding more reliable results without damaging the artwork. The role of copper pigments in the oxidation processes observed in the cellulosic support is discussed, as well as the possible provenance of atacamite as a raw material instead of as a degradation product of malachite.

In this research the thermal stability of paper and its components are investigated, in order to evaluate the effect of the artificial weathering treatments, carrying on measurements of thermal gravimetry; also some SEM observations are performed to follow the degradative phenomena. Our work allowed to correlate the level of degradation of the artificially aged paper samples with that of the naturally aged ones. TGA curves of the weathered samples show changes in respect to the starting materials; particularly, the chemical oxidation appears as the most degradative action in respect to the other physical treatments.

Recent developments in microscopy and image processing have made digital measurements on high-resolution images of fibrous materials possible. This helps to gain a better understanding of the structure and other properties of the material at micro level. In this paper SEM image segmentation based on mathematical morphology is proposed. In fact, paper models images (Whatman, Murillo, Watercolor, Newsprint paper) selected in the context of the Euro Mediterranean PaperTech Project have different distributions of fibers and fillers, caused by the presence of SiAl and CaCO3 particles. It is a microscopy challenge to make filler particles in the sheet distinguishable from the other components of the paper surface. This objectif is reached here by using switable strutural elements and mathematical morphology operators.

We present an overview of the application of some vibrational spectroscopic techniques (Fourier transform infrared (FTIR) and Raman) to industrial archaeology in the field of cultural heritage, particularly centered on the wallpaper industry. Both techniques present a better performance for cost than other set-ups applied to the analysis of multilayer artworks on cellulose supports. To illustrate the applicability of these techniques, we present examples of different decorative wallpapers from the whole nineteenth century and compare the results obtained with other artworks from the same century. Raman spectroscopy was mainly used in pigment determination with the help of FTIR spectroscopy. The study of the binder was better achieved using FTIR spectroscopy, and FTIR could also be used to evaluate semi-quantitatively the degree of the degradation of the cellulose. The wallpaper industry was a very prosperous sector in the nineteenth century that followed the same pattern of the other crafts from the same century, applying the new pigments available in that period. Antique pigments (e.g., minium, red oxides and carbon black) were determined together with new ones, first synthesised during the nineteenth century (e.g., copper-arsenic pigments and ultramarine blue). We observed a transition in the use of the antique pigments to the new ones in the wallpaper items going through the century. The great transformation of the chemical industry was clearly reflected in the evolution of the wallpaper industry during that century.

In the preservation of Cultural Heritage items, the use of polymeric materials for the consolidation and protection of artifacts with historical and artistic value is widely accepted, except for cellulose-based materials, since here there are no suitable products and appropriate application techniques. Grafting polymerization of acrylic monomers onto cellulose chains represents an innovative method of restoration for both artificially and naturally aged textiles. In this article, some results concerning the grafting polymerization of ethyl acrylate/ethyl methacrylate 75/25 and ethyl acrylate/methyl methacrylate/trifluoroethyl methacrylate 73/24.5/2.5 polymers onto linen and cotton are reported. The effectiveness of grafting polymerization as a method for textiles conservation is discussed. The consolidating and protective effects were investigated by evaluating the mechanical properties and the wetting behavior of the grafted samples, and comparing them with the original and aged substrates. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 90–99, 2007

The influence of blend composition on enthalpy-relaxation behaviour was assessed for miscible blends of poly(4-hydroxy styrene)/poly(vinyl methyl ether) (PHS/PVME). Values of enthalpy lost (ΔH(Ta, ta)) were calculated from experimental data plotted against log (ta) and modelled using the Cowie–Ferguson (CF) expression. This gives a set of values for three adjustable parameters, ΔH∞(Ta), log (tc) and β. Positron annihilation lifetime spectroscopy (PALS) measurements indicated that all of the blends, except the blend with 59 mol% of the PHS component, have greater free volume than pure PHS. Furthermore, infrared spectroscopy was useful for assessing the hydrogen-bonding interactions in the blends. The ageing results are discussed with reference to the strength of the interactions and free volumes, and are compared with related systems. Copyright © 2005 Society of Chemical Industry

Grafting polymerisation of methyl methacrylate and ethyl acrylate onto linen and cotton was carried out in order to reinforce these materials, when they underwent degradation. Take into account this aim, an artificially ageing was performed onto cellulose based textiles by metaperiodate oxidation, in order to obtain degraded model samples. Carbonyl groups were introduced in the cellulose and used as photosensitive agents, allowing the formation of radical sites during the polymerisation reaction, that started by irradiating the substrate by ultraviolet light. In this paper the effectiveness of grafting polymerisation as a method for textile conservation is discussed, starting from the results obtained from several characterisations, as the grafting yields and the grafting efficacy evaluation, the DSC analysis, the FTIR spectroscopy and the SEM observations. Moreover the consolidating and the protective effects were investigated by evaluating the mechanical properties and the wetting behaviour of the grafted samples, and comparing them with the original and aged substrates. The mechanical strength of cellulose based textiles has been improved, as well as the wetting behaviour has been enhanced.

An oxidative reaction of cellulose with sodium methaperiodate was performed in order to reproduce the natural ageing of textiles. The oxidised groups were transformed into free macroradicals by treatment with UV light. In presence of acrylic monomers in the vapour phase, these reactive sites become the starting point for the graft copolymerisation of methyl methacrylate and ethyl acrylate onto cellulose. Thermal analysis is a convenient, useful and reproducible method for characterising complex organic materials from plants. In this research we have examined the thermal stability of oxidised and grafted flax and cotton using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) analyses, in order to evaluate the effect of the grafting on their thermal behaviour. In presence of acrylic grafted polymer, the thermal stability of the textiles increases.

Polymeric products are largely used for consolidation of stone in the field of cultural heritage. Nevertheless, the main problem of polymeric compounds is related to their macromolecular nature, it being difficult for a polymer to penetrate inside the pores which may have a very small diameter. These considerations are the starting points for in situ polymerization. According to this technique, not the pre-formed polymer, but the monomer is introduced into the stone and it is polymerized in situ in a subsequent step. Frontal polymerization (FP) is a particular technique in which the heat released by the exothermal reaction of monomer to polymer conversion is exploited to promote the formation of a hot traveling front able to propagate and self-sustain the reaction. In the present work, FP is performed inside the pores of the stone and the results lead to the conclusion that the hot front is still active in the presence of an inorganic material which dissipates partially the heat released during the polymerization. In addition some recent applications of FP are discussed in comparison with the traditional polymerization for the in situ consolidation and protection of stones. Copyright © 2005 John Wiley & Sons, Ltd.

The oxidation reactions of cellulose involve the primary and secondary hydroxyl groups of the pyranose ring and result in carbonyl and carboxyl groups. This reaction can be accompanied by opening the pyranose ring. In any cases the glucosidic bond becomes weaker; the formation of carboxyl groups induces a depolymerisation, thus reducing the polymerisation degree and the physical and mechanical strength of the material. The conversion of 1,2-dihydroxyl groups to dialdehyde by periodate oxidation on cellulose based materials as textiles (flax and cotton) and paper with different composition and characteristics, has been studied. To investigate the cellulose behaviour at different level of oxidation, two different solutions of sodium methaperiodate were used: 0.1 and 0.4 M, for different times of treatment. The oxidised samples become “models” to investigate the different levels of degradation in real materials. Thermal analysis is convenient and reproducible, and is a useful method for characterising heterogeneous organic materials from plants. In this research we have examined the assignment of the exothermic transition in DSC analysis of paper, flax and cotton and its components in order to understand their thermal behaviour in more detail and to evaluate the effect of the oxidation treatment on the thermal behaviour. The aim of our work is to correlate the level of degradation of the oxidised samples with the natural ageing of the real cellulose based materials. The results obtained suggest information in the restoration and conservation field of cellulosic materials.

Estimate of sorption of liquid materials inside porous stones is an important parameter in industrial material testing and cultural heritage conservation. In the latter case, a suitable polymer can be used for both consolidation and conservation, it being applied either in the final form or as its parent monomer, which is subsequently allowed to polymerize in situ by the classical method or by frontal polymerization. However, the sorption of such materials through the stone is often difficult because of their viscosity and/or stone porosity. For this reason, the amount of monomer (or polymer) is a parameter of great interest in order to determine the extent of protection reachable by the treatment. In this paper a new methodology based on X-ray tomography is presented. The methodology makes use of a contrast agent added to the monomer that does not interact with its propagation inside the stone and allows to increase the absorption coefficient and so to observe the monomer inside the sample, which is finally frontally polymerized.

The effectiveness of butyl methacrylate/ethyl acrylate-based copolymers as consolidants for stone was investigated. The penetration of polymeric consolidating products is extremely slight because of their macromolecular nature and in situ polymerization of the monomers is suggested as an alternative technique to the use of macromolecular solutions. The efficiencies of three products synthesized in situ and fluorinated by various copolymers were comparatively evaluated in terms of surface properties, water permeability, and consolidation on a selected stone substrate. Moreover, because the environmental stability of such polymeric products is one of the key factors for their extensive application for conservative treatments, the photooxidative stability of reference polymers prepared in vitro was also investigated. © 2004 Wiley Periodicals, Inc.

In this paper, the properties of some polymeric materials used as consolidating and protective products in the restoration field of stone manufactured objects of artistic interest are discussed. The penetration of polymeric consolidating products is very small because of their macromolecular nature, and in situ polymerization of the monomers is suggested as an alternative technique to the use of macromolecular solutions. The effects of plasticizer agents in the reaction system have been investigated, in order to decrease T g and make the products more elastic.

The solvent effect observed in propene/1- hexene copolymerizations performed with the isospecific catalyst rac-Et(Ind) 2 ZrCl 2 /MAO is studied, A range of solvents with increasing donor character and steric hindrance has been tested, and their effect on copolymer yield, composition, and microstructure has been thoroughly analyzed. Our results demonstrate that the solvent can have a significant influence on the comonomer reactivities, even though the solvent polarity is not the relevant factor. At the same comonomer compositions in solution, polymerizations carried out in coordinating solvents (e.g., aromatic solvents), lead to the formation of products with considerably decreased content of 1-hexene. The reduced incorporation of the higher a-olefin is explained in terms of competition between the nucleophilic medium and the olefin monomer for coordination to the active polymerization site. These results give us valuable information regarding the mechanism of polymerization at the active centers.

The conservation of roofing and cladding materials has both environmental and cultural heritage bearing. Our research aimed at comparing the performances of some polymeric products used for the protection of a typical Italian sandstone, the ‘Agro d'Ardesia’, used mostly as cladding, paving, roofing, and building material. These products belong to three different classes: polysiloxanes, acrylics, and fluoropolymers. In addition, an acrylic–silicone mixture was chosen for testing. After the application onto the Agro sandstone by capillary absorption, both efficacy and durability were assessed. Particularly, two types of weathering tests were performed to check the stability over time of the protective products: the exposure to ultraviolet radiation in a climatic chamber and the ageing by exposure to acid rain, expressly designed to represent realistically natural and anthropogenic changes. Detailed information on treatment performances was obtained. The polysiloxane was shown to be the most effectiv...

Paper and papyrus endurance depends on their intrinsic properties that are related to the manufacture processes and to the environmental conditions (temperature, humidity, presence of micro-organisms, etc.). During the time, paper and papyrus undergo unavoidable ageing processes causing mainly the degradation of the cellulose. In the framework of the European Project "PAPERTECH" a multi-analytical approach was selected to carefully study the behaviour, properties, and the quality of different samples of paper with different provenience, before and after artificial ageing. This work was focused to understand and explain the degradation processes occurring in paper during the time. Portable EDXRF, NMR, Raman, FTIR, AIR, mechanical properties, colour measurement and XRD analyses were performed before and after the accelerated weathering. The light and the chemical oxidation were found to cause the most aggressive ageing processes.

The morphology of polyester-based polyurethanes was observed by transmission electron microscopy, which highlighted a nanostructured system made by a continuous distribution of hard domains with size equal to few nanometres in the soft matrix.

Porous materials were prepared by agglomerating the expanded clay with an epoxy resin with the aim to produce sound absorbers which combine good noise damping performances, excellent mechanical strength and low costs. The use of a polymeric binder, instead of the concrete typically employed in present commercial products, allows obtaining light sound-absorbing panels. In our research the acoustic and mechanical properties of samples of consolidated expanded clay with different thicknesses were experimentally tested. Particularly, the sound absorption properties were measured in a vertical Kundt tube by applying the standing wave ratio method. SEM (scanning electron microscope) observations and porosity measurements were also performed. Experimental results showed a good behaviour with respect to the flexure and compression tests, together with selective sound-absorbing performances and suggest further research opportunities and possible applications of these porous materials as sound absorbers.

In this paper the development of image processing and analysis routines for acquiring information about the paper structure from images obtained by scanning electron microscopy (SEM) is described. A new method to measure the fibre width based on the processing of superficial SEM observation is herein proposed and successfully applied to some commercial paper-based materials. The quantification of fillers in the Z-direction of paper was based on paper cross-sectional SEM images. The results obtained by image processing demonstrated the excellent performance and suitability of the proposed method to quantify exactly information concerning fraction and size distribution of digital fillers. The fraction of digital fillers was correlated with the surface roughness of a given paper grade.

The study of polymer behavior over time represents the crucial stage in the setup of innovative methodologies for paper restoration. In this research, a series of laboratory simulations by accelerated aging and characterization tests by chemical and physical measurements were carried out on paper samples consolidated both by grafting polymerization with acrylic copolymers and by coating with waterborne polyurethanes with the aim of determining their harmlessness and long-term effectiveness. In this way, our purpose was not only to verify possible risks for the paper materials but also to determine the advantages and potentialities of new restoration methods through an appropriate and essential working plan of investigations. From our evaluation, both the selected consolidation methods appeared unsuitable to be used in paper restoration because of the damage that they could cause on the paper materials because of their limited durability over time. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The chemical and biological deterioration of paper-based materials is mainly due to the degradation of its main component, the cellulose. However, paper also contains small amounts of organic and inorganic additives which might influence its biodegradability. To protect the paper-based materials against various degradative agents, coating treatments with polymeric materials might be developed. In this study, the protective effect of commercial waterborne polyurethanes (WPU) against an enzymatic attack was investigated. Uncoated and coated samples with WPU of newsprint were subjected to degradation by enzymatic complexes (cellulosomes) produced by Clostridium cellulolyticum for different incubation times and then characterized using several analytical techniques (energy dispersive X-ray fluorescence, scanning electron microscopy, nuclear magnetic resonance, Raman and infrared spectroscopy) with the aim to assess if waterborne polyurethanes can be used in paper conservation, looking at their efficacy against the biodegradation induced by enzymes. The selected waterborne polyurethanes showed a high effectiveness in the protection of paper-based materials when they were submitted to the enzymatic attack. Indeed, their presence delayed the destruction of the cellulose matrix and the release of both soluble sugars and paper additives. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

A Dutch map from the eighteenth century was multi-analytically analysed making use of energy dispersive X-ray fluorescence (EDXRF), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), Raman and scanning electron microscopy coupled to energy dispersive spectrometry (SEM-EDS). The cellulosic support was characterised and its state of conservation was evaluated. Besides, paramagnetic impurities were detected together with copper metallic chips. The colours present in some areas of the map were also analysed. Vermilion, carbon black and organic pigments were found. Surprisingly, in the green areas, the rare presence of the mineral moolooite (copper oxalate) was detected. A possible biological attack is discussed in order to explain the presence of such compound. Almost all of the techniques used in the analysis were portable, non-destructive and non-invasive, which is very desirable when analysing objects belonging to Cultural Heritage. The need for a multi-analytical approach using portable instrumentation is also discussed.

The kinetics of periodate oxidation of cellulose was followed through the alkaline degradation of the dialdehyde groups by measuring the viscometric degree of polymerisation and the alkali consumption. The obtained results show that a fast but limited attack of periodate occurs in the amorphous region of cellulose, causing the decrease of degree of polymerisation to its levelling-off value. The alkali consumption indicates at least two further slower reactions, that lead to the asymptotic complete oxidation of cellulose units. With the pseudo first-order approximation, the oxidation half-time of these three reactions can be calculated, corresponding to 1.2, 20 and 854 h respectively. In spite of the high oxidation of the analysed samples (up to about 46%), the residue after alkaline degradation shows a relatively high value of degree of polymerisation rather than the narrow molecular weight distribution of oligomers expected from a random oxidation, thus indicating that periodate oxidises cellulose in isolated domains. The sequence of analyses over the same sample utilised in this work (titrimetry, weight loss and viscometry), performed at room temperature in mild conditions, makes it possible to investigate the topochemistry of oxidation of paper and textiles of historic and artistic value with microdistructive techniques on a single, very small fragment of material.

Synthetic polymers have been occasionally applied to the consolidation and protection of paper and cellulose-based textiles especially when traditional conservation methods were not sufficient to improve the mechanical resistance of the degraded artefacts. In this paper, the potential of the innovative technique of grafting polymerisation with synthetic polymers was investigated to prevent biodeterioration. Cotton, linen and Whatman paper were consolidated by a) coating Paraloid B72®, b) coating ethyl acrylate/methyl methacrylate (EA/MMA) preformed copolymer, and c) grafting onto cellulose chains EA and MMA monomers in the ratio 75/25. All the samples were artificially biodeteriorated to obtain biodegraded model samples of both consolidated and non-consolidated substrates, according to the ASTM G21-96(2002) Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi. The consolidating effect was examined evaluating the mechanical behaviour of the grafted and coated samples, before and after the artificial biodeterioration. In addition, SEM observations were applied to monitor both the grafting level and.the biodeterioration of the samples. With the grafting of acrylic monomers, the mechanical strength of cellulose-based textiles and paper was greatly improved, as well as the resistance to biological agents. Therefore, with regards to biodeterioration, the graft copolymer EA/MMA (75/25 wt) was proved to be a suitable method to help prevent possible deterioration of paper and textiles.

Consolidation treatment of porous materials was performed by in situ and frontal polymerization of acrylic monomers inside a porous stone. To study the penetration of the polymer inside the stone and its consolidating effects we used water as a contrast agent, detecting its penetration using unilateral NMR and magnetic resonance imaging. All data obtained on differently treated stones were compared with corresponding ones obtained analyzing both untreated stones and stones simply painted with a well-known polymeric protective agent. In situ polymerization of acrylic monomers inside porous stones has been demonstrated to be an extremely powerful consolidating method, whereas thermally initiated frontal polymerization seems less efficient. In both cases the optimal choice of monomers is still open and requires further study. Our data indicate that unilateral NMR represents an inexpensive and simple technique for the non-invasive observation of the water uptake and of the effect of consolidation procedures in porous materials.

Summary: The deterioration of synthetic polymers caused by biological process is usually evaluated by visual inspection and measuring physical effects. In contrast to this approach, we have applied vibrational spectroscopies to study the biodegradation of the synthetic resins. 29 synthetic resins used as paint binding media, including acrylic, alkyd and poly(vinyl acetate) polymers, were examined for potential susceptibility to fungal degradation using the standard method ASTM G21-96(2002). In addition, the degraded resins were analysed by Raman spectroscopy, FT-IR and FT-IR photoacoustic spectroscopy. Almost all the acrylic resins studied proved to be resistant to microbial attack, while all alkyd resins and some poly(vinyl acetates) turned out to be biodegradable. Within a few days of inoculation Aspergillus niger was the most copious fungus on the biodegraded resins. A comparison of the IR and Raman spectra of control and biodegraded resins did not show any differences, but photoacoustic spectroscopy revealed additional bands for the fungal-degraded resins, consistent with the presence of fungal-derived substances. The additional bands in the photoacoustic spectra were due to the presence of Aspergillus niger and melanin, a fungal pigment. Since IR photoacoustic spectroscopy can be also a suitable technique for the chemical characterisation of binding media, the same spectroscopic analysis can be employed to both characterise the material and obtain evidence for fungal colonization. Microbial growth on Sobral 1241ML (alkyd resin) after 28 d (growth rating 4) compared with the non-inoculated resin.

Grafting of methyl methacrylate and ethyl acrylate onto cellulose chains of textiles with oxidized sites has been carried out. To this aim, carboxyl and carbonyl groups have been introduced by oxidation of the cellulose and used as photosensitive agents, allowing the formation of radical sites. The copolymerization has been started irradiating the substrate with ultraviolet light for a short time. With the grafting of acrylic monomers the mechanical strength and the thermal stability of cellulose based textiles may be improved, as well as the resistance to chemical and biological agents. The method has been successfully tested performing the grafting on a naturally aged cotton sample. It is worth to note that the grafting does not affect the aspect of the material. All samples have been characterized with 13C solid state NMR spectroscopy. A semi-quantitative evaluation of the grafting has been performed either studying the cross-polarization dynamic process, or by direct integration of resonances in 13C single pulse excitation spectra.

Natural polymers, as cellulose, with hydrophilic groups such as hydroxyl groups have various strengths of interaction with water. Cellulose is a structurally heterogeneous polymer, consisting of paracrystalline and amorphous domains. Water can interact with the amorphous domains, but it is excluded almost completely from the crystalline regions. The purpose of this study was to estimate the amount of bulk free water in cellulose based materials, as linen, cotton and paper, by measuring the heats of vaporisation. Moreover the amount of free water in oxidised and grafted samples has been determined by DSC and this quantity has been compared with that found in the corresponding native materials. In oxidised cellulose the water content increases with decreasing the degree of crystallinity; the oxidation, being a degradative reaction, modifies the amorphous content in the cellulose. In presence of acrylic grafted polymer, the free water content is reduced and this reduction is related to the grafting yields.

In the preservation of cultural heritage items, the use of polymeric materials for the consolidation and protection of artifacts with historical and artistic value is widely accepted. This area is vast and includes studies of various objects made of different materials such as wood, stone, textiles, and paper. The aim of this article is to establish the most suitable copolymer for cellulose-based-material restoration according to its properties, as evaluated by several techniques such as 1H-NMR spectroscopy, size exclusion chromatography, differential scanning calorimetry, and dynamic mechanical analysis. In addition to the mechanical property evaluation, an investigation of fungal deterioration has been carried out. Because, in the literature, no complete study concerning the characterization of ethyl acrylate/methyl methacrylate and butyl acrylate/methyl methacrylate copolymers is available, a detailed and full investigation of these polymers is required before the best copolymer is selected for grafting polymerization onto cellulose. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1157–1164, 2005

Conversion of dihydroxyl groups to dialdehyde by periodate oxidation is a useful method widely used in derivatization of cellulose to activate the polymer to further reactions as grafting polymerization. To investigate the cellulose behavior at different level of oxidation and to better understand the influence of the crystallinity on the effects induced by oxidative reactions on different cellulose materials, linen and cotton textiles have been oxidized with periodate solutions in different conditions. Oxidized cellulose samples have been characterized by several techniques: solid-state 13 C NMR, Wide Angle X-Ray diffraction, and SEM. Moreover the mechanical properties of the untreated and oxidized yarns have been evaluated by means of tensile tests, the oxidation degree has been measured by means of the hydroxylamine hydrochloride method.