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Ayyachi, Thayanithi
Publications (3 of 3) Show all publications
Alexakis, A. E., Ayyachi, T., Mousa, M., Olsen, P. & Malmström, E. (2023). 2-Methoxy-4-Vinylphenol as a Biobased Monomer Precursor for Thermoplastics and Thermoset Polymers. Polymers, 15(9), Article ID 2168.
Open this publication in new window or tab >>2-Methoxy-4-Vinylphenol as a Biobased Monomer Precursor for Thermoplastics and Thermoset Polymers
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2023 (English)In: Polymers, E-ISSN 2073-4360, Vol. 15, no 9, article id 2168Article in journal (Refereed) Published
Abstract [en]

To address the increasing demand for biobased materials, lignin-derived ferulic acid (FA) is a promising candidate. In this study, an FA-derived styrene-like monomer, referred to as 2-methoxy-4-vinylphenol (MVP), was used as the platform to prepare functional monomers for radical polymerizations. Hydrophobic biobased monomers derived from MVP were polymerized via solution and emulsion polymerization resulting in homo- and copolymers with a wide range of thermal properties, thus showcasing their potential in thermoplastic applications. Moreover, divinylbenzene (DVB)-like monomers were prepared from MVP by varying the aliphatic chain length between the MVP units. These biobased monomers were thermally crosslinked with thiol-bearing reagents to produce thermosets with different crosslinking densities in order to demonstrate their thermosetting applications. The results of this study expand the scope of MVP-derived monomers that can be used in free-radical polymerizations toward the preparation of new biobased and functional materials from lignin.

Place, publisher, year, edition, pages
MDPI AG, 2023
Keywords
lignin, biomass, emulsion, crosslinking, curing, thiol-ene
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-328318 (URN)10.3390/polym15092168 (DOI)000987483600001 ()37177314 (PubMedID)2-s2.0-85159337521 (Scopus ID)
Note

QC 20230607

Available from: 2023-06-07 Created: 2023-06-07 Last updated: 2024-01-17Bibliographically approved
Lopez, A., Ayyachi, T., Brouwers, T., Aberg, J., Finne Wistrand, A. & Engqvist, H. (2022). 1-Year pullout strength and degradation of ultrasound welded vs tapped craniomaxillofacial fixation screws. Polymer testing, 109, 107519, Article ID 107519.
Open this publication in new window or tab >>1-Year pullout strength and degradation of ultrasound welded vs tapped craniomaxillofacial fixation screws
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2022 (English)In: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 109, p. 107519-, article id 107519Article in journal (Refereed) Published
Abstract [en]

A knowledge on the pullout forces of degradable craniomaxillofacial screws is essential in designing pediatric cranial implants. Herein, four non-identical commercially available screws composed of different aliphatic polyesters were fixated to 3D-printed poly(L-lactide) screw hole test rig and onto a bone substitute material using manual tapping and ultrasonic welding fixation techniques. A method for mechanical testing was developed to determine and compare their quasi-static pullout strength. The degradation of the screws was followed for up to one year in three different degrading environments. While the screw size influences the initial pullout force, the degrading environment, size, and screw composition determine the degradation rate which in turn influences the pullout force over time. Given the limited availability of standard methods, the method developed herein can be used in determining the pullout forces of degradable craniomaxillofacial screws and comparing the effectiveness of various screw insertion techniques.

Place, publisher, year, edition, pages
Elsevier BV, 2022
Keywords
Cranioplasty, Craniomaxillofacial implant, Manual tapping, Ultrasonic welding, Pullout force, Degradation
National Category
Biomaterials Science
Identifiers
urn:nbn:se:kth:diva-312689 (URN)10.1016/j.polymertesting.2022.107519 (DOI)000789617800004 ()2-s2.0-85125802606 (Scopus ID)
Note

QC 20220524

Available from: 2022-05-24 Created: 2022-05-24 Last updated: 2022-06-25Bibliographically approved
Ayyachi, T., Pappalardo, D. & Finne Wistrand, A. (2022). Defining the role of linoleic acid in acrylic bone cement. Journal of Applied Polymer Science, 139(25), Article ID e52409.
Open this publication in new window or tab >>Defining the role of linoleic acid in acrylic bone cement
2022 (English)In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 139, no 25, article id e52409Article in journal (Refereed) Published
Abstract [en]

Polymethylmethacrylate is clinically used as a bone cement in various orthopedic and trauma surgeries. Post the surgery, such conventional acrylic bone cement has been reported to cause adjacent vertebral fractures; modifying it by adding linoleic acid in the formulation has shown potential in averting such fractures thanks to bone-compliant mechanical properties, besides providing convenient handling properties. Although the resulting properties are attractive, the understanding of how linoleic acid imparts such advantageous properties remain unclear. Linoleic acid is typically sterilized in an autoclave before being used in the bone cement formulation; however, there are apprehensions whether the sterilization causes degradation. In this research, sterilized and unsterilized linoleic acid were evaluated alone and with different components of bone cement, such as activator, initiator, monomer, and inhibitor, and the ensuing structural changes in linoleic acid were monitored through 1H NMR and UV–Vis. The results reveal that linoleic acid degrade due to sterilization. In addition, evidence for reactions of sterilized/unsterilized linoleic acid with activator and initiator have been collected. We hypothesize that these reactions can reduce the availability of the components for the in situ polymerization of methyl methacrylate monomer and cause the improvement in handling properties and decrease in mechanical properties. 

Place, publisher, year, edition, pages
Wiley, 2022
Keywords
biomaterials, biomedical applications, lipids, Acrylic monomers, Esters, Sterilization (cleaning), Surgery, Acrylic bone cements, Handling properties, In-situ polymerization, Methyl methacrylate monomer, Polymerization of methyl methacrylate, Property, Vertebral fractures, Medical applications
National Category
Clinical Medicine
Identifiers
urn:nbn:se:kth:diva-322394 (URN)10.1002/app.52409 (DOI)000780367600001 ()2-s2.0-85127236647 (Scopus ID)
Note

QC 20221214

Available from: 2022-12-14 Created: 2022-12-14 Last updated: 2022-12-14Bibliographically approved
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