Elastomer surface energy modification applying oxygen and nitrogen plasma treatment with laser deactivation of the surface

Golob, Gorazd (2011) Elastomer surface energy modification applying oxygen and nitrogen plasma treatment with laser deactivation of the surface. Dissertation (PhD) thesis. Grafički fakultet. [Mentor: Lovreček, Mladen].

Preview

PDF Doktorski rad Golob Gorazd.pdf Download (4MB) | Preview

Abstract

Cilj doktorske teze je istraživanje površinske slobodne energije, hrapavosti i drugih svojstva površine NBR i EPDM ofsetnih “gumenih navlaka“, funkcionalizacija površinskih svojstva obradom pomoću kisikove i dušikove plazme te defunkcionalizacija površine primjenom IR i UV lasera. Karakterizacija površinske slobodne energije mjerenjem kontaktnog kuta primjenom testnih tekućina sa različitom površinskom napetošću i polarnošću, SEM (skenirna elektronska mikroskopija), XPS (spektroskopija rendgenskim zrakama) i analiza hrapavosti ispitivanih elastomera i njihovih komponenti, daje kvantitativni opis za plazmu specifičnih površinskih funkcionalnih grupa, koje su u korelaciji s površinskom energijom, polarnošću i drugim površinskim svojstvima spomenutih materijala, tako da se mogu procijeniti promjene adsorpcijskog potencijala, odnosno njegova hidrofilna/oleofobna ili hidrofobna/ oleofilna svojstva. Kemijska analiza površine elastomera (“gumene navlake“) nakon obrade plazmom i laserom, u usporedbi sa neobrađenim uzorcima, pokazuje velike promjene samo kod sumpora, koji je korišten za vulkanizaciju. Druge, manje vidljive promjene u kemijskoj strukturi nastale su zbog kemijskih reakcija čestica plazme sa silika punilom ili sa dodacima, radije nego sa osnovnom makromolekularnom strukturom elastomera. Kod nevulkanizirane sirove gume nema vidljivih kemijskih promjena nakon obrade kisikovom plazmom ili UV laserom, uz istovremene značajne promjene površinske slobodne energije i polarnosti. Kod sirove gume promjene su uzrokovane promjenom makromolekularne strukture površine. “Gumena navlaka“ dobro je poznati medij za prijenos tiskarske boje u ofsetnom i drugim konvencionalnim i digitalnim tiskarskim tehnikama, gdje djeluje kao sekundarna tiskovna forma. Zapisivanje na površinu “gumene navlake“ pomoču obrade plazmom i laserom za selektivnu defunkcionalizaciju, otvara nove mogučnosti u njezinoj upotrebi o ulogi nosioca slike u tiskovnom procesu i time novi izazov za buduča istraživanja.

Item Type:	Dissertation (PhD) thesis
Mentor name:	Lovreček, Mladen
Other mentors:	Mozetič, Miran
Thesis Committee:	Bolanča, Stanislav and Lovreček, Mladen and Mozetič, Miran and Klanjšek Gunde, Marta and Džimbeg-Malčić, Vesna
Defence date:	2011
Abstract in english:	The aim of the thesis was to investigate the surface free energy, roughness and other surface properties of NBR and EPDM lithographic offset “rubber blankets“, to functionalize the surface properties with an oxygen and nitrogen plasma treatment, and to defunctionalize the surface by applying IR and UV lasers. The characterization of the surface free energy with contact angle measurements using test liquids with different surface tension and polarity, SEM (scanning electron microscopy), XPS (X-ray photoelectron spectroscopy), and roughness analysis of the investigated elastomers and their components provided a description of specific surface functional groups that are in correlation with the surface free energy, polarity and other surface characteristics of elastomers. Therefore, their adsorption potential changes and their hydrophilic/ oleophilic or hydrophobic/oleophobic properties can indirectly be evaluated. The chemical analysis of the surface of elastomer (“rubber blanket“) after the plasma and laser treatment, compared to the untreated samples, showed significant changes only in sulphur used as the curing agent. Other, less significant changes in the chemical composition occurred due to the chemical reactions of plasma species with the silica filler or additives, rather than with the basic macromolecular structure of the elastomer. With the uncured crude rubbers, there were no apparent chemical changes after the oxygen plasma or UV laser treatment, while there were simultaneously significant changes in the surface free energy and polarity. With crude rubber, the changes took place due to the changes in the macromolecular structure of the surface. “Rubber blanket“ is a well-known ink transfer media in lithographic offset and other conventional or digital printing techniques, where it is used as the secondary printing forme. The rendering of the “rubber blanket“ surface by using a plasma and laser treatment for a selective defunctionalization is opening new possibilities in using the “rubber blanket“ as an image carrier in the printing process and thus offers a new challenge for future research.
Uncontrolled Keywords:	elastomer, ofsetna gumena navlaka, plazma, površinska slobodna energija, laser
Keywords in english:	elastomer, offset rubber blanket, plasma, surface free energy, laser
Subjects:	TECHNICAL SCIENCES > Graphic Technology
Institution:	Grafički fakultet
City:	Zagreb
Number of Pages:	205
Callnumber:	681.654.5:655.344 gol d
Inventory number:	8946
Status:	Unpublished
Date Deposited:	15 Nov 2013 21:47
Last Modified:	17 Nov 2014 10:47
URI:	http://eprints.grf.unizg.hr/id/eprint/1434

Actions (login required)

View Item