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Titolo:
HALS stabilization of LDPE films used in agricultural applications
Autore:
Kaci, M; Sadoun, T; Cimmino, S;
Indirizzi:
Univ Bejaia, Mat Organ Lab, Bejaia 06000, Algeria Univ Bejaia Bejaia Algeria 06000 a, Mat Organ Lab, Bejaia 06000, Algeria CNR, Ist Ric & Tecnol Mat Plast, I-80072 Arco, Napoli, Italy CNR Arco Napoli Italy I-80072 cnol Mat Plast, I-80072 Arco, Napoli, Italy
Titolo Testata:
MACROMOLECULAR MATERIALS AND ENGINEERING
fascicolo: 5, volume: 278, anno: 2000,
pagine: 36 - 42
SICI:
1438-7492(200005)278:5<36:HSOLFU>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
LOW-DENSITY POLYETHYLENE; AMINE LIGHT STABILIZERS; HINDERED-AMINE; PHOTOSTABILIZING MECHANISMS; PHOTO-STABILIZATION; POLYMERS; PHOTOOXIDATION; POLYPROPYLENE; DEGRADATION; POLYOLEFINS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
43
Recensione:
Indirizzi per estratti:
Indirizzo: Kaci, M Univ Bejaia, Mat Organ Lab, Bejaia 06000, Algeria Univ Bejaia Bejaia Algeria 06000 rgan Lab, Bejaia 06000, Algeria
Citazione:
M. Kaci et al., "HALS stabilization of LDPE films used in agricultural applications", MACRO MAT E, 278(5), 2000, pp. 36-42

Abstract

The mechanism of stabilization of low density polyethylene (LDPE) films used in agricultural applications with hindered amine light stabilizer (HALS)has been studied under the influence of natural weather for 750d. The structural modifications in the exposed films were monitored by Fourier transform infrared spectroscopy (FTIR), while the examination of the surface behavior was performed by scanning electron microscopy (SEM). Finally, the stability of the material was evaluated by measuring the percent elongation at break. The performance of HALS in the films was analyzed through a comparative study carried out on unstabilized LDPE samples exposed to the same weathering conditions for 170 d. The FTIR results have shown that HALS reduces significantly the rate of formation of ketone groups in the exposed films due to deactivation of the excited ketonic carbonyls. This indicates the roleof HALS to prevent the occurrence of Norrish I and II reactions. On the other hand, the development of vinyl groups at 909 cm(-1) in the film and thephotooxidation of the polymer. The decrease observed in the ester band suggests the loss of the stabilizer. For the unstabilized LDPE film, the results have revealed a fast increase in both ketonic and vinyl groups attributed mainly to Norrish II reactions. This resulted in chain scission responsible for both the rapid drop in elongation at break and the considerable deterioration of the surface of the exposed film. On the contrary, the presenceof HALS in the film resulted in a large retention of the elongation at break. Moreover, SEM analysis reveals the role of HALS to prevent the surface damage by reducing the number and size of microcracks.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/07/20 alle ore 17:12:18