Search results for " Materiali"

The solidification behavior of a PBT/PET blend over a wide range of cooling rate

2009

In recent years, much attention has been paid to the development of high-performance polyester blends, among which blends of polybutylene terephtha- late/polyethylene terephthalate (PBT/PET) are expected to exhibit remarkable prop- erties as far as their crystallization behavior is concerned. Through trial and error, appropriate commercial compositions have been chosen which could not be otherwise explained by a suitable interpretation of the mechanisms determining their solidifica- tion behavior. The solidification behavior of a 60/40 w/w PBT/PET blend was studied in a wide range of cooling conditions, according to a continuous cooling transforma- tion (CCT) procedure developed previously,…

Theoretical Predictions and experimental determination of cloud point curves for polymeric solutions: an application to the ternary system Poly-lacti…

2011

The lattice fluid model with specific interactions was applied to the ternary system Poly-L-lactic-acid (PLLA)-dioxane-water. Model parameters were determined by fitting experimental data. The as-obtained parameters were used to calculate the complete phase diagram. An experimental apparatus for cloud point measurements, which is under construction, is presented.

Effect of pressure on the PVT behaviour of iPP as revealed by dilatometric measurements

2002

Isotactic Poly-propylene samples, previously prepared under known conditions of pressure and cooling rate by means of a special apparatus designed and set-up by the authors, were subjected to several isobaric runs at low cooling and heating rate in a confining fluid dilatometer (by GNOMIX). The effect of the previous thermo-mechanical histories and the effect of pressure in the dilatometry on specific volume of the samples was studied. Results show that the initial specific volume depends upon the previous thermo-mechanical histories, which however cancels out after the first heating run. Moreover the reported dilatometric experimental data support the evidence that an increase of pressure …

Poly-left-lactic acid tubular scaffolds via diffusion induced phase separation: Control of morphology

2013

n this work, tubular poly-left-lactic acid scaffolds for vascular tissue engineering applications were produced by an innovative two-step method. The scaffolds were obtained by performing a dip-coating around a nylon fiber, followed by a diffusion induced phase separation process. Morphological analysis revealed that the internal lumen of the as-obtained scaffold is equal to the diameter of the fiber utilized; the internal surface is homogeneous with micropores 1–2 μm large. Moreover, a porous open structure was detected across the thickness of the walls of the scaffold. An accurate analysis of the preparation process revealed that it is possible to tune up the morphology of the scaffold (w…

PLA/PLLA scaffold for vascular tissue engineering applications

2011

A critical obstacle encountered by tissue engineering is the inability to maintain large masses of living cells upon transfer from the in vitro culture conditions to host in vivo. Capillaries, and the vascular system, are required to supply essential nutrients, including oxygen, remove waste products and provide a biochemical communication “highway”. Another task in this research field is the possibility to tune the biodegradability of the scaffold. After implantation, the scaffold must be gradually populated by cells and replaced by extra cellular matrix; with this respect, it is crucial that this replacement takes place with appropriate dynamics and a well-defined timescale. A premature d…

PREPARATION AND HYDROLYTIC DEGRADATION OF POLY LACTIC ACID BASED SCAFFOLDS

2012

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Influence of "Controlled Processing Conditions" on the solidification of iPP, PET and PA6

2002

In this work reliable experimental data for three semicrystalline polymers (iPP, PA6, PET) crystallised under pressure and high cooling rates are supplied. These results were achieved on the basis of a model experiment where drastic "controlled" solidification conditions are applied. The final objective was to quantify the effect of two typical operating conditions (pressure and cooling rate) on the final properties and morphology of the obtained product. The influence of processing conditions on some macroscopically relevant properties, such as density and micro hardness is stressed, together with the influence of processing conditions on the product morphology, investigated by means of Wi…

The concept and the application of no-flow temperature (NFT) in simulation of injection moulding

2009

Pre-vascularized PLLA scaffolds: A new approcah to develop deep tissue regeneration

2010

Patent number RM2009A000073: Procedimento di preparazione di scaffold polimerici preangiogenizzati

2009

Classe proposta A61F - Filtri da inserire nei vasi sanguigni; protesi; apparecchi ortopedici e curativi per contraccezione; fomentazione; trattamento o protezione degli occhi e delle orecchie; bendaggi, garze per medicazioni e assorbenti; necessario per il pronto soccorso