present status of radiation technology in italy p.g. fuochi, m. lavalle, u. corda [email protected]...

Present Status of Radiation Technology in Italy

P.G. FUOCHI, M. LAVALLE, U. CORDA [email protected]

Institute for the Organic Synthesis and PhotoreactivityItalian National Research Council

Via P. Gobetti, 101 - 40129 Bologna Italy - www.isof.cnr.it

First Planning and Coordination Meeting - Technical Coordination Project RER/8/010First Planning and Coordination Meeting - Technical Coordination Project RER/8/010Quality Control Methods and procedures for Radiation TechnologyQuality Control Methods and procedures for Radiation Technology

Warsaw 21-25 February 2005Warsaw 21-25 February 2005

In Italy, there are presently six 60Co -irradiators and eight EB accelerators devoted to industrial uses.

Beside that eight 60Co -cells or panoramic -beams together with four EB accelerators are in research centres used for basic and applied research.

Sources of ionizing radiation for radiation Sources of ionizing radiation for radiation processing, basic and applied researchprocessing, basic and applied research

P.G. FUOCHI, M. LAVALLE, U. CORDA Institute for the Organic Synthesis and Photoreactivity Italian National Research Council

In Italy, radiation sterilization of disposable medical products by rays has been in commercial use since the beginning of the seventies.

GAMMARAD ITALIA - Bologna

Radiation processing plants and their activities irradiation plants

Service centres for irradiation of raw materials for cosmetic and pharmaceutical products, diets for pathogen-free animals, plastic, metal and glass containers and packaging in general, patient-care items, toothpicks, powder for mud-bath treatments, clothing for biological labs and operating rooms, beehives with their wax frames, culture substrate cakes for mushrooms and to a lesser extent polymer or plastic scraps and Teflon wastes.

Two plants with maximum activities of 1 and 5 MCi

- Como

Two plants with maximum activities of 0.5 and 1.5 MCi


Latina

One plant whit maximum activity of 0.3 MCi

Ascoli Piceno

One plant whit maximum activity of 2 MCi

In-house facilities for sterilization of their production of medical devices.

Radiation processing plants and their activities irradiation plants


Grace-Cryovac - Rho (Milan)

Two RPC low energy accelerator (ca. 1973)

1) Electron energy 300 keV, maximum current 300 mA, first one to be installed in Italy,

2) Electron energy 800 keV, maximum current 90 mA

On-line production of shrink film and bag products, non-shrink laminate products for protective, presentation and food packaging in the industrial and consumer markets.

• Bipan - Codroipo (Udine) (1990-1991)

Electrocurtain accelerator (ESI) with electron energy 300 keV, maximum current 500 mA

For production and cure of wood laminated panels and boards for furniture and parquet.

Radiation processing plants and their activitiesElectron beam irradiation plants


Metallurgica Bresciana - Dello (Brescia) (1993-1994)

RadiationDynamics 1.5 MeV Dynamitron accelerator electron energy, 50 kW average power



for production of radiation cross-linked wires and cables to be used in harsh environments for civil, military and industrial applications and for off-shore platform instrumentations.

Seriate (Bergamo)


Two linear accelerators

1) Scanditronix: electron energy 10 MeV, beam power 20 kW (1995)

2) Linac Technologies: electron energy 10 MeV, beam power 20 kW (near Padova)-’97

For radiation sterilization of disposable medical products and biological laboratory supplies, cork for bottles, packaging items (bottles, caps, stoppers), raw materials for cosmetics and pharmaceutical industries, semiconductors and plastic wastes.


•Gambro Dasco - Medolla (Modena)

IBA Rhodotron TT100, Electron energy 10 MeV, beam power 30 kW

It came into operation at the end of 1997 as in-house accelerator used for sterilization of blood-line products manufactured in its factory.

•Megarad - Cassino (Caserta)

ILU6 2 MeV accelerator has been delivered in 1997.

After a period of tests it came into operation and it is used forproduction of heat-shrinkable tubings.



Università degli Studi di Pavia

Department of General Chemistry

The department has a home-made 60Co -cell with a maximum activity of about 8 kCi (650 Ci at

Jan.2005)

The group of Pavia’s University is involved in the following projects with financial support from industry:

a) radiation chemistry of perfluoropolyethers,

b) radiation-induced oxidation and stabilization of polyolefins: polypropylene, polyethylene, polypropylene-polyethylene copolymers,

c) reactions induced by radiations in elastomer/filler composites,

d) development of polymeric micromatrices by irradiation for drug delivery systems and their radiolytic mechanism.

The aim of the research is to elucidate the radiolytic processes in polymer materials exposed to radiation. Knowledge of the radiolytic behaviour is needed to ascertain the suitability and the lifetime of the materials, to assess the possible negative effects with respect to their use and to find useful stabilizers. Radiation is used to modify the properties of the materials and to generate free radicals to be employed as probes for molecular mobility measurement and for studies on interactions at the polymer/filler interface.

Applied research using 60Co sourcesand EB accelerators


Department of Chemical Engineering, Processing and Materials

The department has a home-made 60Co -cell with actual activity of about

500 Ci

This group is involved in four main projects:

a) functionalization and stabilization studies of polymeric systems for composite materials by means of radiation,

b) development of polymeric micromatrices by radiation for drug delivery systems,

c) radiation-induced polymerization and modification of polymers in CO2 based supercritical fluids for polymer blends,

d) irradiation of blends of epoxy resins and polymethylmethacrylate with rubbers.



The institute is equipped with:• two Nordion 220 gamma cells with actual activities 700 and 1.4 kCi,• a panoramic Nordion Gammabeam 150A with activity of 1.44 kCi• a 12 MeV Vickers linear accelerator.



ISOF - CNRIn collaboration with other public research institutions and industrial companies, experimental work has been done with the aim to develop knowledge and competence useful for the national industries. The activity carried out with private companies is related to irradiation of single items and prototypes to be used for testing and characterization or for particular applications.Specific research activities conducted in the Institute and connected to industrial processes are:1) Synthesis and characterization of hydrogels and their use for entrapment of biologically active species like drugs for their controlled release in the body’s patient or bacteria used in the treatment of contaminated water. The methodology is well known and is based on low temperature radiation-induced polymerization of acrylic and methacrylic glass-forming monomers.



ISOF - CNR2) Radiation-induced graft polymerization of hydrophilic monomers onto polyphosphazenes, inorganic polymers having the general formula [NP(R2)]n, where R can be an alkyl, aryl, alcoxy, aryloxy or amino group. Chemical and mechanical properties as well as biocompatibility of such samples have been evaluated.


RadiationGrafting

Biocomponent

ChemicalBinding

Polymer

Graft-Copolymer

B

Monomer

B B

ImmobilizedProduct

B BB

B B B

Water, Monomer Cross-

linking agent, Additives

Biocomponent

Irradiation at ambient

temperature

Cross-linked gel with

biocomponent

Homogeneous aqueous solution

of biocomponent and monomer

Cooling Formation of

voids, ice, and monomer phases

Irradiation at low temperature

Polymer matrix, biocomponent in

pores


ISOF - CNR3) The antioxidant properties of fural glucitol, a compound used in the cosmetic industry as a skin protective agent against the damage caused by sunlight have been recently studied.



4) Radiation induced genetic mutation in Cannabis sativa has been successfully achieved. The new cultivar thus obtained has been patented. We are now trying to induce mutations in Artemisia annua, a herb from which a powerful antimalarial drug is extracted, by irradiation in order to obtain new morphological properties.

ISOF - CNR1) High energy electron beams have been used to sterilize human bone tissues:

femoral heads to be used as biocompatible material in phrosthesis implants, skull fragments sterilized before their implants in the same patient.

2) Power semiconductor devices are electron irradiated on semi-industrial scale in order to achieve modelling of their electrical parameters and specific adjustment of carrier lifetime.



ISOF - CNR6) ISOF Institute has supported the activities of Laben-Proel Tecnologie, a space R&D company in Florence, for the E-beam irradiation with the linear accelerator. E-beam irradiation has been applied for curing thick composites that can have a wide range of applications, from aerospace to automotive applications:a) to look for commercially available EB curable resins and test their characteristics after E-beam irradiation in order to identify those having features as closer as possible to the end-user requirements,b) to develop its own formulation of acrylated and epoxy resins to be EB cured. In particular

the addition of «onium salts» (salts with an organic cation and an inorganic anion) to epoxy resins made them curable by electron beam,c) to prepare a database including the best polymerization conditions for each resin. The composites cured by bulk polymerization by using high energy E-beams were used as reference for testing those obtained by a process, patented by Laben-Proel, consisting in the filament winding technique (or layer by layer polymerization) with low energy E-beam, a process that permits to manufacture composites without limits in thickness.



ISOF - CNR 7a) In collaboration with researchers at the Department of Chemical Engineering, Processing and Materials of the University of Palermo PMMA-rubber blends have been obtained through E-beam induced in situ polymerization. The dispersion of elastomeric particles into the bulk of thermoplastic brittle polymers is a well-known technique to improve toughness. Blending of elastomeric and thermoplastic components can be performed both through physical and chemical techniques with a lot of drawbacks as for the final morphology of the blend. An alternative way can be the use of rays or accelerated electrons. The influence of rubber nature (ABN, SBR and VTBNX rubbers were used), irradiation dose and dose rate have been investigated. Some blend formulations presented significant increase of ductility with respect to pure PMMA, without deep decrease of modulus, yield stress and stress at break values. 7b) Due to the high technological interest (many patents on radiation curing of epoxy/photo-initiator systems are reported) E-beam curing of bis(4-glycidyloxyphenil)methane, as epoxy monomer, in presence of an iodonium salt, as photo initiator, is under study to better understand the curing mechanism and the influences of the processing parameters. Systems with different concentrations of photo initiators have been polymerized at various dose rates and the materials thus obtained have been tested by dynamical mechanical thermal analysis (DMTA) and their structures analyzed with SEM.




ISOF - CNR8) Development of new dosimetry systems (physical and chemical) and characterization

of existing dosimeters for high dose dosimetry have been undertaken in different conditions (a water cooled tantalum converter is used for the generation of X rays and irradiation of small samples can be done under controlled temperature) and a bipolar transistor has been tested with success as routine dosimeter.9) The electronic engineers of ISOF have also developed a prototype of electrostatic low

energy electron accelerator to be used for on- line sterilization of plastic bottles and pasteboard packings for beverages. Its characteristics are as follows:electron energy 350 keV,beam current 10-20 mA,scanning frequency up to 250 Hz,scan width 12 cm,beam diameter 2.5 cm.

10) Many irradiation tests have been done in the last five years on irradiation modification of different types of polymer, polymers blends and laminated fabrics, synthetic leather in the form of films or sheets used for garments and accessories for outdoor activities and for car seat cushioning and interior decorative cloth lining. The success was such that two of these companies are shipping now their production to E-beam plants in Switzerland and Germany to be processed there.


Casaccia Research Center (Rome)

The centre is equipped with:• a pool-tipe irradiation facility of about 20 kCi ,• a 3 MeV S band pulsed electron linear accelerator with 0.2 A peak current.

These equipments are used for radiation processing research on materials such as wires and cables, electronic components and detectors to be used in particular in harsh environments (nuclear plant, aerospace, etc.). Special attention has been devoted lately to develop scintillating glasses and wide-gap crystals and to study the effects of irradiation (radiation damage and radiation resistance) on their transmission properties.



Tecnotessile - Prato (Florence)The institute is equipped with a Crosslinking AB electron accelerator with 280 keV electron energy and 1 kW beam power:


Tecnotessile is a national company for services and technological consultancy with partners both public and private. In collaboration with the Department of Chemistry of the Polytechnic Institute in Milan has carried out a research project for the development of a new process and textile products. The process, that has been patented, applies the preirradiation method of grafting. In this process linen and cotton fabrics are first irradiated and then passed through in a solution containing glycidyl methacrylate. The latter becomes attached to functional groups present in the treated fabrics; all the process is done under inert atmosphere. In this way functionalised finished fabrics are obtained for textile production. The technique can be applied to natural and synthetic fibres and textiles.


National Institute of Nuclear Physics - MessinaThe institute is equipped with a 5 MeV linear accelerator with peak energy of 5 MeV, peak current of 200 mA, 1 MW peak power, pulse repetition rate 1-300 Hz

It will be used to study several applications of radiation processing.Furthermore, the very compact structure of this accelerator makes it very suitable to develop a system for in situ industrial radiography or X-ray tomography.



The above overview on the status of radiation technology in Italy is by no means exhaustive, some applications and applied researches are kept secret or not easily accessible to the authors. The prospects of radiation technologies, in spite of the great interest aroused, will depend much upon the availability of equipments and related technology at affordable costs, as it has been pointed out in many IAEA Meetings. The availability of accelerators, radiation-curable polymer formulations, functional monomers or oligomers will help in encouraging the industries, that seem reluctant to adopt some well accepted practice of radiation treatment due to public awareness, worker protection, little or no familiarity or knowledge of the new processes, to overcome these drawbacks and adopt a technology that has been proved to be efficient, cost saving, environment friendly and has high production rates with respect to the traditional thermal or/and chemical processes.

Conclusions


present status of radiation technology in italy p.g. fuochi, m. lavalle, u. corda [email protected]...

Documents

maximum activities

organic synthesis

research centres

applied research

maximum current

corda institute

radiation technology

sources of ionizing