Research Repository

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The development of a novel technique for small ring specimen tensile testing (2018)
Journal Article
Kazakeviciute, J., Rouse, J., De Focatiis, D., & Hyde, C. (2019). The development of a novel technique for small ring specimen tensile testing. Theoretical and Applied Fracture Mechanics, 99, 131-139. doi:10.1016/j.tafmec.2018.11.016

The wide scale use of small specimens in routine testing programs could significantly reduce material resource requirements (factors of 10 are easily achievable). This is a major benefit to situations where there is not enough material to manufacture... Read More

Frictional behaviour of non-crimp fabrics (NCFs) in contact with a forming tool (2018)
Journal Article
Avgoulas, E. I., Mulvihill, D. M., Endruweit, A., Sutcliffe, M. P., Warrior, N. A., De Focatiis, D. S., & Long, A. C. (2018). Frictional behaviour of non-crimp fabrics (NCFs) in contact with a forming tool. Tribology International, 121, 71-77. doi:10.1016/j.triboint.2018.01.026

Microscopic observation and analysis are used to examine the role that contact conditions play in determining the frictional behaviour of non-crimp fabrics (NCFs). The true fibre contact length is measured over a range of normal pressures. For the NC... Read More

The roles of blending and of molecular weight distribution on craze initiation (2017)
Journal Article
Sánchez-Valencia, A., Smerdova, O., Hutchings, L. R., & De Focatiis, D. S. (in press). The roles of blending and of molecular weight distribution on craze initiation. Macromolecules, 50(23), doi:10.1021/acs.macromol.7b01289. ISSN 0024-9297

Craze initiation stress was measured in three-point bending isochronal creep tests on a series of entangled bimodal blends of polystyrenes of narrow dispersity, on three polystyrenes of broad dispersity, and on four blends of polystyrenes of broad di... Read More

Compression moulding of composites with hybrid fibre architectures (2016)
Journal Article
Corbridge, D., Harper, L. T., De Focatiis, D. S., & Warrior, N. (2017). Compression moulding of composites with hybrid fibre architectures. Composites Part A: Applied Science and Manufacturing, 95, doi:10.1016/j.compositesa.2016.12.018. ISSN 1359-835X

Advanced Sheet Moulding Compounds (ASMC) and unidirectional (UD) prepregs have been co-compression moulded to form a hybrid composite material. In-mould flow influences the UD fibre architecture in two ways. When UD fibres are aligned transversely to... Read More

Compounding and rheometry of PLA nanocomposites with coated and uncoated hydroxyapatite nanoplatelets (2016)
Conference Proceeding
Tomczynska, M. M., Choong, G. Y., De Focatiis, D. S., Grant, D. M., & Parsons, A. J. (in press). Compounding and rheometry of PLA nanocomposites with coated and uncoated hydroxyapatite nanoplatelets

Polylactic acid and novel nanoplatelets of hydroxyapatite (HANP) were compounded in a laboratory scale twin-screw extruder and injection moulded to shape. The effect of HANP loading content, between 1 wt% and 10 wt%, and of HANP surface coating with... Read More

A model for the compressible, viscoelastic behavior of human amnion addressing tissue variability through a single parameter (2015)
Journal Article
parameter. Biomechanics and Modeling in Mechanobiology, 15(4), doi:10.1007/s10237-015-0739-0. ISSN 1617-7959

A viscoelastic, compressible model is proposed to rationalize the recently reported response of human amnion in multiaxial relaxation and creep experiments. The theory includes two viscoelastic contributions responsible for the sho... Read More

High-pressure rheological analysis of CO2-induced melting point depression and viscosity reduction of poly(ε-caprolactone) (2015)
Journal Article
Curia, S., De Focatiis, D. S., & Howdle, S. M. (2015). High-pressure rheological analysis of CO2-induced melting point depression and viscosity reduction of poly(ε-caprolactone). Polymer, 69, doi:10.1016/j.polymer.2015.05.026. ISSN 0032-3861

High-pressure rheology has been used to assess the effects of supercritical carbon dioxide (scCO2) on the melting point (Tm) and viscosity of poly (ε-caprolactone) (PCL) over a range of temperatures and pressures up to 300 bar over a wide range of sh... Read More

Time-dependent mechanical behavior of human amnion: Macroscopic and microscopic characterization (2014)
Journal Article
Mauri, A., Perrini, M., Ehret, A. E., De Focatiis, D. S., & Mazza, E. (2015). Time-dependent mechanical behavior of human amnion: Macroscopic and microscopic characterization. Acta Biomaterialia, 11, doi:10.1016/j.actbio.2014.09.012. ISSN 1742-7061

Characterizing the mechanical response of the human amnion is essential to understand and to eventually prevent premature rupture of fetal membranes. In this study, a large set of macroscopic and microscopic mechanical tests have been carried out on... Read More

The role of deformation history on stress relaxation and stress memory of filled rubber (2014)
Journal Article
Fernandes Arruebarrena, V. A., & De Focatiis, D. S. (2014). The role of deformation history on stress relaxation and stress memory of filled rubber. Polymer Testing, 40, doi:10.1016/j.polymertesting.2014.08.018. ISSN 0142-9418

Although the magnitudes of inelastic and viscoelastic effects in filled rubbers are small relative to that of the elastic response, these effects are nevertheless critical in applications such as gaskets, seals and dampers. This study investigates th... Read More

A novel nethod of extraction of blend component structure from SANS measurements of homopolymer bimodal blends (2014)
Journal Article
Smerdova, O., Graham, R. S., Gasser, U., Hutchings, L. R., & De Focatiis, D. S. (2014). A novel nethod of extraction of blend component structure from SANS measurements of homopolymer bimodal blends. Macromolecular Chemistry and Physics, 215(9), doi:10.1002/macp.201300787. ISSN 1022-1352

A new method is presented for the extraction of single chain form factors and inter-chain interference functions from a range of small angle neutron scattering (SANS) experiments on bimodal homopolymer blends. The method requires a minimum of three b... Read More

Viscoelastic melt rheology and time-temperature superposition of polycarbonate – multi-walled carbon nanotube nanocomposites (2013)
Journal Article
Choong, G. Y., De Focatiis, D. S., & Hassell, D. G. (in press). Viscoelastic melt rheology and time-temperature superposition of polycarbonate – multi-walled carbon nanotube nanocomposites. Rheologica Acta, 52(8), doi:10.1007/s00397-013-0706-6. ISSN 0035-4511

This work investigates the linear and non-linear viscoelastic melt rheology of four grades of polycarbonate melt-compounded with 3 wt% Nanocyl NC7000 multi-walled carbon nanotubes and of the matching matrix polymers. Amplitude sweeps reveal an earlie... Read More

Large deformations in oriented polymer glasses: experimental study and a new glass-melt constitutive model (2010)
Journal Article
De Focatiis, D. S., Embery, J., & Buckley, C. (2010). Large deformations in oriented polymer glasses: experimental study and a new glass-melt constitutive model. Journal of Polymer Science Part B: Polymer Physics, 48(13), doi:10.1002/polb.22028. ISSN 0887-6266

An experimental study was made of the effects of prior molecular orientation on large tensile deformations of polystyrene in the glassy state. A new hybrid glass-melt constitutive model is proposed for describing and understanding the results, achiev... Read More

Melt-processed PLA/HA platelet nanoparticle composites produced using tailored dispersants
Conference Proceeding
Parsons, A. J., Walton, K., Hild, F., Ilchev, A., Gimeno-Fabra, M., Tomczynska, M. M., …Irvine, D. J. (in press). Melt-processed PLA/HA platelet nanoparticle composites produced using tailored dispersants

Hydroxyapatite (HA) nanoparticles, similar to those seen in the structure of human bone, have been produced via hydrothermal synthesisand used to produce nanocomposite materials via melt blending with poly(lactic acid)(PLA). Both of these processes a... Read More