0000000000351692
AUTHOR
Sari Rautiainen
Design and development of 100 % bio-based high-grade hemp/epoxy composites
International audience; In order to develop 100% bio-based high-grade epoxy composites, in this study, bio-based epoxy thermosets and hemp slivers are processed and characterized by different technologies. Epoxy resins are synthesized from the diglycidylether of Eugenol, extracted from cloves. They are cured with bio-based acid anhydrides. The physicochemical properties of the resulting epoxy resins are characterized using thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), and nanoindentation. The mechanical properties of hemp fibres extracted from the slivers are also determined using tensile tests. After their processing and characterization, these bio-based consti…
Design and synthesis of biobased epoxy thermosets from biorenewable resources
International audience; Biobased diepoxy synthons derived from isoeugenol, eugenol or resorcinol (DGE-isoEu, DGE-Eu and DGER, respectively) have been used as epoxy monomers in replacement of the diglycidyl ether of bisphenol A (DGEBA). Their curing with six different biobased anhydride hardeners leads to fully biobased epoxy thermosets. These materials exhibit interesting thermal and mechanical properties comparable to those obtained with conventional petrosourced DGEBA-based epoxy resins cured in similar conditions. In particular, a high Tg in the range of 90–130 °C and instantaneous moduli higher than 4.3 GPa have been recorded. These good performances are very encouraging, making these n…
Towards Fully Bio-Based Thermosets: From Prepolymers Synthesis to Composite Applications
International audience
Kolmiportainen tukimalli esiopettajien arvioimana - haastattelututkimus
Kämppi, Tuovi ja Rautiainen, Sari. KOLMIPORTAINEN TUKIMALLI ESIOPETTAJIEN ARVIOIMANA Erityispedagogiikan pro gradu -työ. Jyväskylän yliopiston kasvatustieteiden laitos, 2014. 89 sivua. Julkaisematon. Tämän tutkimuksen tarkoituksena oli selvittää esiopettajien käsityksiä ja kokemuksia kol-miportaisen tuen toteuttamisesta esiopetuksessa. Kiinnostuksen kohteena olivat tuen tasot, arviointi, monitahoinen yhteistyö sekä kolmiportaisen tukimallin periaatteet, inkluusio ja varhainen puuttuminen. Tämän lisäksi selvitettiin kolmiportaisen tukimallin kehittämis- ja koulutuksellisia tarpeita esiopettajien arvioimana. Aiheen tutkiminen oli ajankohtaista, koska kolmiportaisuus on melko uusi asia ja sitä…