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The plagues of stored products consist of a man problem, depreciating products and causing economical damages. Among these curses we have Lasioderma serricorne (F. 1792), Sitophilus zeamais (M. 1855) and Plodia interpunctella (H. 1813) known by infesting stored products as: grains, brans, flours, coffee, tobacco, dried fruits and spices. These curses perforate and penetrate the packages, ovipositing over the substratum. In this context the package plays a fundamental part, preventing the contact and curses’ proliferation in the packed product. So, to protect the packed product and to prolong its shelf life, the package should have good mechanical resistance to tension and perforation, good sealing, good barrier properties and should not transfer odors nor strange flavors to the packed product. The ionizing radiation can cause structural changes in polymer packages, these changes are caused by the scission processes and reticulation of the polymers chains. These are concurrent processes and the predominance of one over the other depends on the chemical structure of the polymer, the irradiation conditions and specific factors of the material that will absorb the energy. This work had the objective to evaluate the changes in mechanical properties of package structures used to store granola, cereal bar and pasta, as well as its resistance to perforation by L. serricorne, P. interpunctella and S. zeamais, when submitted to electrons sheaf radiation. In this methodology were used five structures of commercially utilized packages to store granola, cereal bar and pasta composed by (Polypropylene bi‐oriented metallic/Polypropylene bi‐oriented coextruded ‐ BOPPmet/BOPP 50 μm), (Polypropylene bi‐oriented/Polypropylene ‐ BOPP/PP 50 μm), Poli (ethylene terephthalate) metallic/Polypropylene bi‐oriented coextruded ‐ PETmet/BOPP 32 μm), Poli (ethylene terephthalate) /Polypropylene ‐ PET/PP1 72 μm), Poli (ethylene terephthalate)/Polypropylene ‐ PET/PP2 32 μm). The structures of packaging were submitted to radiation doses between 0, 10, 20 and 60 kGy, in one electron accelerator of 1,5 M and V, 25 mA and 37,5 kW, dose tax of 11,22 kGy / s, room temperature and air presence . Eight days, Two and Six months after irradiations, mechanical resistance experiment were accomplished to tension and elongating in rupture, sealing resistance and perforation resistance, all based in respective ASTM norms. The perforation experiment by insects were realized in an acclimatized room, where irradiated samples in doses of 0, 10, 20 and 60 kGy were sealed containing 40 g of granola, 40 g of pasta and cereal bar in number of nine by experiment, and equally divided in three plastic screened boxes by studied dose. In each box 20 adults of each insect were added in for 60 days, when the packages were evaluated to verify possible perforations. The differences between the sample results were statistically evaluated by ANOVA (p<0.05). The results showed that concerning the perforation resistance by L. serricorne, P. interpunctella and S. zeamais the polymeric structures evaluated showed low resistance by insects perforation before and after the treatment. BOPPmet/BOPP (50 μm), PETmet/BOPP (32 μm), PET/PP1 (72 μm) and PET/PP2 (32 μm) structures showed significant losses in mechanical properties studied. The BOPP/PP (50 μm) showed the best set of answers in mechanical properties to the radiation treatment with electrons sheaf up to 10 kGy doses. Among the mechanical properties evaluated, sealing was the most affected by ionizing radiation, has shown, in general, increasing losses with radiation dose. SUMÁRIO Página 1. INTRODUÇÃO  01 2. OBJETIVOS E ASPECTOS RELEVANTES  02 2.1 Objetivo do trabalho  02 2.2 Aspectos relevantes  02 3. CONTRIBUIÇÃO E ORIGINALIDADE DO TRABALHO  02 3.1 Contribuição do trabalho  02 3.2 Originalidade do trabalho  03 4. REVISÃO BIBLIOGRÁFICA  04 4.1 Principais pragas em alimentos  04 4.2 Ordem Coleoptera.  06 4.2.1 Família Anobiidae 07 4.2.1.1 Lasioderma serricorne (Fabricius, 19792).  08 4.2.2 Família Curculionidae  12 4.2.2.1 Sitophilus zeamais.  14 4.3 Ordem Lepidoptera  16 4.3.1 Família Pyralidae 19 4.3.2 Subfamília Phycitinae  20 4.3.3 Plodia interpunctella.  21 5. Embalagem  25 5.1 Polímeros e embalagens plásticas flexiveis  27 5.2 Conceito de polímeros e outros conceitos  28 5.3 Embalagens plásticas flexíveis  31 5.4 Polímeros usados como materiais de embalagens  32 5.4.1 Polietileno PE  32 5.4.1.2 Polipropileno PP  35 5.4.1.3 Polipropileno bi-orientado BOPP  36 5.4.1.4 Poliamida PA  36 5.4.1.5 Copolímero de etileno e acetato de vinila EVA  37 5.4.1.6 Copolímero de etileno e álcool vinílico EVOH  38 6. Radiação ionizante  40 6.1 Efeito fotoelétrico  41 6.1.2 Efeito comptom  43 6.1.3 Produção de pares  44 6.2 Radiação ionizante de interesse para a química de polímeros  45 6.2.1Raios gama  45 6.2.2 Feixe de elétrons  45 6.2.2.1 Aceleradores de elétrons  46 7. Efeitos da radiação ionizante sobre os materiais poliméricos  50 8. MATERIAIS E MÉTODOS  58 8.1 Materiais  58 8.1.1 Materiais – filmes flexíveis  58 8.1.2 Outros materiais  59 8.2 Métodos  62 8.2.1 Ensaios de irradiação com feixe de elétrons  62 8.2.2 Ensaio de resistência à perfuração por Lasioderma serricorne, Plodia interpunctella e Sitophilus zeamais  63 8.3 Ensaios mecânicos 63 8.3.1 Ensaios mecânicos de resistência a tração e porcentagem de elongação  64 8.3.2 Ensaios mecânicos de resistência à perfuração  64 8.3.3 Ensaios mecânicos de resistência da selagem  64 9. Infraestrutura  65 10. RESULTADOS E DISCUSSÕES  66 10.1 Resultados de perfuração a embalagens por insetos  66 10.2 Resultados dos ensaios mecânicos  67 10.2.1 Estrutura BOPPmet/BOPP (50 μm)  67 10.2.2 Estrutura BOPP/PP (50 μm)  70 10.2.3 Estrutura PETmet/BOPP (32 μm)  72 10.2.4 Estrutura PET/PP1 (72 μm)  75 10.2.5 Estrutura PET/PP2 (32 μm)  77 11. CONCLUSÕES  82 12. SUGESTÕES PARA TRABALHOS FUTUROS  82 REFERÊNCIAS BIBLIOGRÁFICAS

Avaliação dos efeitos da radiação por feixe de elétrons na resistência de embalagens a Lasioderma serricorne, Plodia interpunctella e Sitophilus zeamais