| 1. |
- Kupka, Vojtech, et al.
(författare)
-
Well-dispersed polyurethane/cellulose nanocrystal nanocomposites synthesized by a solvent-free procedure in bulk
- 2019
-
Ingår i: Polymer Composites. - : WILEY. - 0272-8397 .- 1548-0569. ; 40, s. E456-E465
-
Tidskriftsartikel (refereegranskat)abstract
- Polyurethane (PU) nanocomposites utilizing cellulose nanocrystals (CNCs) as nanofiller and amorphous PU matrix were synthesized in a novel solvent-free bulk process. A green nanofiller, CNCs, was studied as reinforcement and was further modified by grafting poly(ethylene glycol) (PEG) on the CNC surface (CNC-PEG). Transmission electron microscopy revealed an excellent dispersion of the PEGylated CNC nanoparticles in the PU matrix, whereas as-received CNCs formed agglomerates. The results indicated strong improvements in tensile properties with Young's modulus increasing up to 50% and strength up to 25% for both, PU/CNC and PU/CNC-PEG nanocomposites. The enhanced tensile modulus was attributed to stiff particle reinforcement together with an increase in glass transition temperature.
|
|
| 2. |
- Polacek, Petr, et al.
(författare)
-
The shear adhesion strength between the FRC substructure and denture base resin : Effects of FRC architecture, adhesive composition and hydrolytic degradation
- 2013
-
Ingår i: Composites Science And Technology. - : Elsevier BV. - 0266-3538 .- 1879-1050. ; 77, s. 22-28
-
Tidskriftsartikel (refereegranskat)abstract
- The adhesion strength between fiber reinforced composite (FRC) members and denture-base resin is pivotal for enhancing removable denture long lasting performance and patient comfort. FRC reinforcing rods based on glass fibers impregnated with light curing resin were used to model the FRC substructure. The influence of fiber architecture and adhesive layer composition on the shear adhesion strength, tau(a). between the FRC and denture-base resin was investigated both dry and in moist environment to assess the stability of the adhesive bond in the oral cavity. The obtained results suggest that for a given fiber architecture, adhesive composition and test conditions, the wetting of the FRC surface was the primary variable affecting the tau(a). In the case of good wetting and formation of adhesive bond between the substrates, interlaminar shear strength of the unidirectional FRC substrate was the limiting factor. In multidirectional FRC substrate, the shear strength of the outer resin rich layer was limiting factor for the maximum adhesion strength.
|
|
