Studij utjecaja hidrolitičkog, toplinskog i UV starenja na svojstva papira za restauriranje

doctoral thesis

• Title (english): Impact study of hydrolitic, thermal and UV ageing on the properties of paper for restauration
• Author: Marijana Mimica Tkalčec
• Mentor: Mirela Leskovac (mentor)
• Committee member: Danijela Ašperger (predsjednik povjerenstva)
• Committee member: Sanja Lučić Blagojević (član povjerenstva)
• Committee member: Lahorija Bistričić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2019-04-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences; Materials
• Universal decimal classification (UDC): 66 - Chemical technology. Chemical and related industries

Abstract

Velik dio kulturne baštine nalazi se zapisan na papiru, koji tijekom duljeg vremenskog perioda pod utjecajem različitih okolnih čimbenika podliježe promjenama i propadanju. Kako bi se dobio uvid u mehanizme djelovanja različitih čimbenika koji utječu na degradaciju papira (celuloze), različitim postupcima ubrzanog starenja u laboratorijskim uvjetima nastoji se simulirati procese koji se u prirodnim uvjetima odvijaju tijekom duljeg vremenskog perioda. Jedan od načina da se poveća stabilnost papira (celuloze), jest impregnacija papira za restauriranje različitim adhezivima. Osnovni cilj ovog istraživanja bio je utvrditi i definirati utjecaj hidrolitičkog i UV (eng. Ultraviolet) starenja na stabilnost papira za restauriranje. Kako bi se usporio proces degradacije papira u radu su istražene mogućnosti primjene različitih adheziva na površini papira s namjerom da se uspori proces degradacije papira. Provedena su istraživanja ubrzanog (laboratorijskog) hidrolitičkog i UV starenja papira tijekom različitih vremena. Ispitivanja su provedena na tri vrste japanskog papira (JP1, JP2 i JP3) koji se uobičajeno koriste u restauratorske svrhe prije i nakon premazivanja adhezivima: metil-celulozom (MC), rižinim škrobom (RS), klucelom G (K, hidroksipropil-celulozom) i filmoplastom R (F, kopolimer estera akrilne kiseline). U radu su sustavno praćena strukturna, površinska, kemijska i mehanička svojstava ishodnih JP1, JP2 i JP3 papira i papira premazanih adhezivima nakon određenog vremena ubrzanog hidrolitičkog i UV starenja. Promjene u strukturi tijekom degradacije praćene su FTIR spektroskopskom analizom (eng. Furier Transform Infrared Spectroscopy). Mjerenjem kontaktnog kuta utvrđene su promjene površinskih karakteristika papira dok su mjerenja stupnja polimerizacije (DP, eng. Degree of Polymerization) i mehaničkih svojstava korištena za određivanje konačnih svojstava papira uvjetovanih degradacijom. Toplinska svojstva praćena su DSC (eng. Differential Scanning Calorimetry) i TGA (eng. Thermal Gravimetric Analysis) analizom. Dobiveni rezultati ukazuju na različite mehanizme degradacije ovisno o vrsti laboratorijskog starenja. Utvrđeno je da
UV zračenje značajnije utječe na degradaciju papira u odnosu na hidrolitičko starenje što potvrđuju niže vrijednosti stupnja polimerizacije i slabija mehanička svojstva. Na osnovi mjerenja prekidne čvrstoće postavljen je matematički model koji opisuje degradaciju čistog papira i papira premazanih adhezivima pri različitim uvjetima starenja. Utvrđeno je da istraživane sustave papir i papir/adheziv bolje opisuje jednadžba Ding-a i Wang-a koja uključuje dodatni parametar kapaciteta rezerve. Rezultati su pokazali da se premazivanjem papira adhezivima MC, RS i K poboljšavaju mehanička svojstva, njihova stabilnost te da se usporavaju procesi degradacije papira. Na osnovi dobivenih rezultata vidljivo je da najbolji zaštitni učinak pokazuje sloj rižinog škroba na svim japanskim papirima dok laminacija filmoplastom R ima suprotan učinak na stabilnost papira te ubrzava degradaciju papira.

Abstract (english)

Large part of heritage has been written on the paper that easily deteriorates if exposed to various environmental factors over long periods of time. In order to better understand factors affecting paper (cellulose) degradation, ageing of paper is performed under controlled laboratory conditions that simulate natural conditions during long periods of time. One of the methods to improve paper (cellulose) stability is by treating the paper with adhesives. The main purpose of this study was to determine and define the influence of hydrolytic and UV (ultraviolet) ageing on the stability of restoration paper. In order to slow down the process of paper degradation, in this work the possibilities of applying different adhesives to the paper surface were explored. Investigations of accelerated (laboratory) hydrolytic and UV ageing of paper were carried out with different ageing durations. The tests were carried out on three types of Japanese paper (JP1, JP2 and JP3) commonly used for restorative purposes. Results were obtained before and after treatment with adhesives: methyl-cellulose (MC), rice starch (RS), klucel G (K, hydroxypropyl-cellulose) and filmoplast R (F, copolymer of acrylic acid ester). In this study the structural, surface, chemical and mechanical properties of the untreated JP1, JP2 and JP3 papers and papers treated with adhesives were systematically monitored during accelerated hydrolytic and UV ageing. Changes in structure during degradation were monitored by FTIR spectroscopic analysis (Furier Transform Infrared Spectroscopy). Contact angle measurements indicated changes in surface characteristics of the paper, while degree of polymerization (DP) and mechanical properties were used to determine the final properties of paper caused by degradation. Thermal properties were monitored by DSC (Differential Scanning Calorimetry) and TGA (Thermal Gravimetric Analysis) analysis. The obtained results indicate different mechanisms of degradation depending on the type of laboratory ageing. It was found that UV radiation significantly contributes to the degradation of paper relative to hydrolytic ageing, which confirms lower DP values and lower mechanical properties. Based on strength measurements, a mathematical model was created that describes the degradation of untreated paper and paper treated with adhesives at different ageing conditions. It was concluded that the investigated paper and paper/adhesive systems are better described by the Ding and Wang equation which includes an additional reserve capacity parameter. The results showed that paper treated with MC, RS and K adhesives has improved mechanical properties, paper stability and paper degradation processes is slow down. Based on the obtained results, it is evident that the layer of rice starch on all Japanese papers shows the best protective properties, while lamination with filmoplast R has the opposite effect on paper stability and accelerates paper degradation.

• Keywords: celuloza; degradacija; hidrolitičko starenje; UV starenje; adhezivi; slobodna energija površine; stupanj polimerizacije; mehanička svojstva
• Keywords (english): cellulose; degradation; moist heat ageing; UV ageing; adhesives; surface free energy; degree of polymerization; mechanical properties
• Language: croatian
• URN:NBN: urn:nbn:hr:149:161640
• Promotion: 2019
• Study programme: Title: Chemical Engineering - Doctoral Course; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti, polje kemijsko inženjerstvo (doktor/doktorica znanosti, područje tehničkih znanosti, polje kemijsko inženjerstvo)
• Type of resource: Text
• Extent: 186 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-08-29 10:06:38