what is the problem? - home - yococu · 8 solvents selected + green rescue *varnish removal from...
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A new green product
Andrea Macchia, Laura Rivaroli, Gaia Fagiolo
YOCOCU- YOuth in COnservation of CUltural Heritage
What is the problem?...... First: Cleaning the surface. I suppose
Testing was performed with mixtures of different solvents using Teas triangle diagram of solvents
Some common mixtures employed in restoration. Note that the acronyms stem from the Italian name of the solvents. DMF= dimethylformamide; n/a = not applicable.
Mixtures Components ratio
2 A water + ammonia 1:1
3 A water + acetone + ethanol 1:1:1
4 A water + ammonia + ethanol + acetone 1:1:1:1
AB water + butylamine 1:1
ABD water + butylamine + DMF 1:1:1
Benzine 80°C–100°C Hydrocarbons n/a
Nitro thinner mixture of esters. ketones. alcohols. and aromatic hydrocarbons variable. depending on the producer
DA DMF + amyl acetate 1:1
DAN DMF + amyl acetate + nitro thinner 1:1:1
DIDAX DMF + synthetic thinner + xylol + acetone (35 + 15 + 10 + 10 mL. respectively)
3.5:1.5:1:1
Ligroina Petroleum ether. Aceton. Ethanol variable
White spirit Hydrocarbons n/a
MEK
Ligroina. MEK……………are toxic materials for the restorer and the environment
R.E.A.C.H. = Registration.Evaluation.Authorisation.of Chemicals
Green Chemistry R.E.A.C.H.
Review of M.S.D.S. ENVIRONMENT. WORKPLACE. IMPACT ON SAFETY for WORKERS
Is this applied in CH sector?
AIM
To set up a green product for the removal of old and modern varnishes
To transfer industrial products to cultural
heritage field
The result
But keep calm…
Experimentation Survey of solvents: Easy to find on the market e.g. solvents used in drug. food and painting industries Low toxicity
Production of laboratory specimens to perform cleaning tests with 9 solvents
In situ tests on real case studies
Experimentation 8 solvents selected + Green Rescue
*VARNISH REMOVAL FROM PAINTINGS USING IONIC LIQUIDS by Maria Filipa Pacheco and oth.-Departamento de Conservacao e Restauro.Universitade Nova de Lisboa. Portugal 2013)
DAMAR. RETOUCHER. PVA and PMMA*
Ageing : SUNTEST CPS + (168h and 336h)
Cleaning system: swab (Solvent: 2.5 ml )
Evaluation of cleaning efficacy (presence of residues): • Restorer’s observations • Micro FTIR • Spectrocolorimeter • UV/VIS imaging
Two paintings (18th-19th century)
4 types of varnishes + black pigment (no IR)
Red pigment + linseed oil
Canvas (15x15 cm)
Selection of Solvents
Easy to find on the market
Low toxicity - High LD50
High Boiling Point
Low Vapour Pressure
Low or No VOC
High Flash Point
No Mutagenicity. Cancerogenicity
OPPORTUNITIES GIVE BY GREEN
SOLVENT
What are Green Solvents?
• Chemicals manufactured using fermentation route /renewable resources
• Minimize the use and generation of hazardous substances
• They meet the goal to minimize environmental impact
Therefore They are – A sustainable Option
GBL – Solvents from renewable resource
• Ethanol
• Ethyl Acetate
• Paraldehyde
• 1,3-Butanediol
• Acetaldehyde diethyl acetal
• Acetic Acid
• Ethyl Lactate
• Levulinic acid and esters
Ethanol
• Renewable solvent
Molasses Ethanol
• Fermentation Reaction
• Properties & Applications
Low toxicity and pleasant odour
Possesses bactericidal and fungicidal activities Can be found as a solvent in numerous oral liquid formulations and
OTC medicines
Can be used as an extraction solvent in herbal medicinal products
Has applications in the personal care industry, paints, coatings, printing inks, flavour and fragrance industries
Ethyl Acetate
• One of the most popular Solvent
Molasses Ethanol
• Esterification reaction
Ethyl Acetate
CH3CH2OH + CH3COOH CH3COOCH2CH3 + H2O
• Properties & Applications
Low toxic and possesses fruity odour
Widely used as a solvent for API manufacturing
Used in agrochemical, personal care & Fragrance industries
In paints act as an activator or hardener
As a solvent it is pretty harmless to the environment and human beings
Ethyl Lactate
• A renewable Solvent
Molasses Lactic Acid Ethyl Lactate
• It’s an important organic ester
• Biodegradable solvent with excellent properties and low toxicity being
produced by lactic acid aqueous solution and ethanol, via an esterification
process
CH3CH(OH)CO2H + C2H5OH CH3CH(OH )CO2C2H5 + H2O
Green Acetals
Green Alcohols + Green Acetaldehyde
• Acetals can be used to replace
dichloromethane
Green Acetals
Toluene, Benzene, Xylene and
• Used in sectors - Coatings, Inks, Adhesives, Cosmetics,
Agrochemicals & potentially in any sector
Pharmaceuticals,
• Advantages - High solvent power, variable evaporation rates & polarity
Dibasic Ester (DBE)
• Environmentally friendly organic solvent derived from a plant by-product stream.
• Dibasic esters are excellent solvent substitutes in many parts cleaning and stripping
application
Low VOC (may qualify for LVP-VOC consumer product exemptions) Readily Biodegradable
Selected solvents C A S Name Chemical formula
109-87-5 Methylal C H3O C H2O C H3
108-32-7 Propylene
carbonate
C4H6O3
2568-90-3 Butylal C H3(C H2)3O C H2O (C H 2)3 C H3
109-99-9 T H F C4H8O /-CH2CH2OCH2CH2-\
646-06-0 Dioxolan 1.3 DIOXACYCLOPENTANE
67-64-1 Aceton ( C H 3 )2 C O
78-93-3 M E K C H3 C O C H2C H3
108-88-3 Toluen C7H8
105-57-7 Diethoxyethane C6H14O2
Physical properties
Green Rescue 1.04 140 91 4.2
NAME Density
g/lt
Boiling point° C Flash Point
° C
Vapour pressure
Kpa
Methylal 0.86 42.3 - 30.5 40
Propylene carbonate 1.2 242 132 0.04
Butylal 0.84 180 62 20
T H F 0.88 66 - 21.5 17
Dioxolan 1.06 76 2.5 10.1
Aceton 0.79 56 - 17 24
M E K 0.8 80 - 1 12.1
1,1-Diethoxyethane 0.83 102 102 18
Methylal
. Butylal
Ethylene carb.
T H F
Dioxolan
Aceton
M E K
Toluen
Ethanol T.O.U.
0
2
4
6
8
10
12
14
0 1 2 3 4 5 6 7 8 9
ðp
ðh
Hansen Graph
Green Rescue Area
Green Rescue Petroleum ether. Aceton. Ethanol*
* Paolo Cremonesi «L'uso dei solventi organici nella pulitura di opere policrome»
Natural and synthetic resins
WAXES
OILs
Ageing OILs Proteins
Toxicological Characteristics
Green Rescue 4300 800 No
@ D.N.E.L.(Derived No Effect Level = is an indicator for determining the hazardous effects upon human health of chemicals substances (is measured in mg and compared with cubic meter of work place during 8 ours. Evidently value is easily and rapidly reached by volatile .see Tab.2
this
Name LD50 mg/Kg @DNEL mg/m3/gg
VOC
Methylal 2000 130 100%
Propylen carbonate 34900 80 No
Butylal 6500 130 No
T H F 1650 150 100%
Dioxolan 2000 50 100%
Aceton 5800 500 100%
M E K 3300 600 100%
1,1-Diethoxyethane - - -
Ageing 168hr and 336hr Starting point Cleaning
Methylal Ethanol with 20 %
MEK
Propylen carbonate
Butylal Green rescue
T H F Dioxolane Aceton M E K
L* 40.340 40.653 40.517 41.319 40.172 40.307 40.691 39.562 40.267
a* 45.088 45.896 45.239 47.880 43.040 43.315 45.606 42.561 43.601
b* 25.775 24.319 25.328 27.779 23.685 24.068 26.013 24.119 24.406
c* 51.936 50.183 51.847 55.358 49.127 49.555 52.504 48.921 49.969
PARALOID
Starting point Ageing 168hr
L* 33.411 30.074
a* 28.844 12.148
b* 15.119 5.703
c* 32.572 13.421
Color surface without varnish
Starting point
L* 40.782
a* 43.290
b* 23.122
c* 49.727
PARALOID
RED Pigment + LINSEED OIL
GREEN RESCUE
MEK
paraloid
Methylal Dietho xyethane
Propil carbonate
Butylal Green rescue T H F
Dioxolane Acetone M E K
damar
Methylal Diethoxy ethane
Propil carbonate
Butylal Green rescue T H F
Dioxolane Acetone M E K
retoucher
Methylal Dietho xyethane
Propil carbonate
Butylal Green rescue T H F
Dioxolane Acetone M E K
PVA
Methylal Propil carbonate
Dietho xyethane
Butylal Green rescue T H F
Dioxolane Acetone M E K
Results + = low ++ = medium +++ = good ++++ = excellent
Retoucher P V A Damar Paraloid
Metilale ++ ++ + +++
Diethoxyethane +++ ++ + ++++
Propylen carbonate + + + +++
Butylal +++ ++ ++++ ++
Green Rescue ++++ ++++ ++ ++++
T H F +++ +++ +++ ++++
Dioxolane ++ ++ +++ ++++
Aceton ++ ++ + ++++
M E K +++ +++ +++ ++++
Green Rescue MEK
MEK
Green Rescue
MEK
Green Rescue
Mannequins, A. L. Casalini, fronte
Rimozione di vernici sovrammesse con strati di porporina
Armatura del XVIII secolo di proprietà dello Studio Moretti Caselli di Perugia
Omnia venenum sunt: nec sine veneno quicquam existit. Dosis sola facit. ut venenum non fit.
Conclusions