Study on the Improvement of Physical-Mechanical Characteristics in the EVA/PVC Blends Irradiation with Electron Beam in the Presence of Triallylisocyanurate

Abstract

ABSTRACT. The paper presents irradiation of thermoplastic elastomers based on ethylene-vinyl acetate (EVA) and poly(vinyl chloride) (PVC) plasticized with small ionizing radiation doses, in the presence of triallylisocyanurate (TAC), for the purpose of improving their characteristics. Results obtained from the study have shown that by irradiating blends of EVA/PVC in presence of TAC, new materials with improved properties have been obtained, as a result of crosslinking reactions and reorientation of sample particles under the influence of accelerated electrons. The optimal irradiation dose and the optimal TAC concentration can be chosen depending on the composition of each blend and on the applications of the final product. KEY WORDS: EVA, PVC, TAC, irradiation, physico-mechanical properties STUDIU PRIVIND ÎMBUNÃTÃÞIREA CARACTERISTICILOR FIZICO-MECANICE ALE AMESTECURILOR EVA/PVC IRADIATE CU ELECTRONI ACCELERAÞI ÎN PREZENÞADE TRIALILIZOCIANURAT REZUMAT. Lucrarea prezintã iradierea unor elastomeri termoplastici pe bazã de etilen vinil acetat (EVA) ºi policlorurã de vinil (PVC) plastifiatã cu doze mici de radiaþie ionizantã, în prezenþã de trialilizocianurat (TAC), cu scopul de a îmbunãtãþi caracteristicile acestora. Rezultatele obþinute în urma studiului au arãtat cã prin iradierea amestecurilor de EVA/PVC în prezenþa TAC, s-au obþinut materiale cu proprietãþi îmbunãtãþite, ca urmare a reacþiilor de reticulare ºi de reorientare a particulelor probelor sub influenþa electronilor acceleraþi. Doza optimã de iradiere ºi concentraþia optimã de TAC se pot alege în funcþie de compoziþia fiecãrui amestec în parte ºi de utilizãrile produsului final. CUVINTE CHEIE: EVA, PVC, TAC, iradiere, proprietãþi fizico-mecanice ETUDE SUR L'AMÉLIORATION DES CARACTÉRISTIQUES PHYSIQUES ET MÉCANIQUES DES MÉLANGES EVA/PVC IRRADIÉS PAR FAISCEAU D'ÉLECTRONS DANSLA PRÉSENCE DE TRIALLYL ISOCYANURATE RÉSUMÉ. Cet article présente l'irradiation d'élastomères thermoplastiques mélanges à base d'éthylène-acétate de vinyle (EVA) et le chlorure de polyvinyle (PVC) plastifié avec de faibles doses de rayonnements ionisants en présence du triallyl isocyanurate (TAC) afin d'améliorer leurs propriétés. Les résultats obtenus à partir de l'étude ont montré que par l'irradiation des mélanges EVA/PVC en présence de TAC on a obtenu des matériaux avec des propriétés améliorées en raison des réactions de réticulation et la réorientation des particules d'échantillons sous l'influence des électrons accélérés. La dose optimale de radiation et la concentration optimale de TAC peuvent être choisies selon la composition de chaque mélange séparément et selon les utilisations du produit final.

The Crosslink Density of Ethylene-Vinyl-Acetate Copolymer/Triallylcyanurate Mixture Cross-linked by Electron Processing

“…Co-agenþii sunt molecule organice multi-funcþionale extrem de reactive faþã de radicalii liberi [9]. Ei sunt folosiþi ca aditivi reactivi pentru a creºte eficienþa de vulcanizare [10][11][12].…”

“…Co-agents are multi-functional organic molecules which are highly reactive towards free radicals [9]. They are used as reactive additives to boost the vulcanization efficiency [10][11][12].…”

The Influence of Electron Beam Irradiation Dose and Polyfunctional Monomers Concentrations on the Physico-mechanical Characteristics of the EPDM/HPDE Blends

“…Iradierea materialelor polimerice produce grefarea ºi ulterior formarea unei reþele tridimensionale prin unirea macroradicalilor generaþi [2]. Principalele avantaje ale iradierii comparativ cu alte metode folosite pentru prelucrarea materialelor elastomerice, plastice sau elasto-plastice în scopul îmbunãtãþirii proprietãþilor lor sunt: (a) se poate aplica direct pe produsul finit, oferind stabilitate dimensionalã, (b) proprietãþile ºi caracteristicile specifice ale radiaþiilor ionizante conduc la obþinerea de produse cu proprietãþi îmbunãtãþite ºi unice, care în alte condiþii ºi prin alte metode nu pot fi atinse, (c) utilizând acceleratoare de electroni de mare putere, emisiile de compuºi organici volatili sunt reduse, energia este utilizatã mai eficient, iar procesul este mai bine controlat [3][4][5]. Literatura de specialitate aratã cã adãugarea de monomeri polifuncþionali (MPF) adecvaþi, numiþi ºi coagenþi, conduce la obþinerea proprietãþilor fizice dorite la doze de iradiere scãzute.…”

“…Materiile prime utilizate au fost urmãtoarele: cauciuc EPDM de tip Nordel 4760 (vâscozitate Mooney 70 ML la 1+4 120°C, conþinut de etilen 70%, 5-etilidenenorbornenã 3 (ENB) 4,9 wt %, densitate 0,88 g/cm , gradul cristalin 10%), 3 HDPE de tip Hostalen GC 7260 (densitate 0,962 g/cm ºi…”

“…Irradiation of polymeric materials results in grafting and subsequently formation of a three dimensional network through the union of generated macro radicals [2]. The main advantages of irradiation compared to other methods used in elastomeric, plastic or elastic-plastic materials processing, in order to improve their properties are: (a) it can be directly applied to the finished product, offering dimensional stability, (b) due to ionizing radiation properties, certain characteristics can be improved or products with unique properties can be obtained, which cannot be achieved using other methods, (c) by using high power accelerators volatile organic compound emissions are reduced, energy is better used and a more exact control of the process is obtained [3][4][5]. Research papers have been published suggesting that appropriate polyfunctional monomers (PFMs), also called coagents, added in polymer matrix could be used to obtain desired physical properties of the blend at lower irradiation doses.…”