Research Article Study of Natural and Accelerated Weathering on Mechanical Properties of Antioxidants Modified Low Density Polyethylene Films for Greenhouse Othman Al Othman, 1,2 Shan Faiz, 1 and Muhammad Abduh Tuasikal 1 1 Chemical Engineering Department, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia 2 Deanship of Graduate Studies, he Saudi Electronic University, Riyadh, Saudi Arabia Correspondence should be addressed to Shan Faiz; sfaiz@ksu.edu.sa Received 16 March 2014; Revised 15 July 2014; Accepted 29 July 2014; Published 20 August 2014 Academic Editor: Geofrey R. Mitchell Copyright © 2014 Othman Al Othman et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Natural and accelerated weatherings were studied to inspect the efect of antioxidants to protect low-density polyethylene (LDPE) ilms for commercial application as greenhouse covering materials in Saudi Arabia. In this investigation, six diferent formulations of LDPE ilm with incorporation of antioxidants were prepared and compared with neat LDPE. he samples were extruded and blown into a ilm using twin-screw extruder and ilm blowing machine. he LDPE ilms were exposed for outdoor weathering in Riyadh during the period of 90 days (mid of June to mid of September) while the accelerated tests were performed by Weather- Ometer. he ilm having 0.2 wt% Alkanox-240 (AN-0.2) stabilizers showed the highest tensile strength among all samples during natural and 100-hour accelerated weathering (10.9 MPa and 21.8 MPa, resp.). he best elongation at break was witnessed in 0.2% Good-rite antioxidants which were 64% in natural weathering; however, 0.5% Good-rite antioxidants showed 232% in accelerated weathering. he ilm having 0.5 wt% Good-rite 3114 (GR-0.5) antioxidant could withstand 70 days during natural exposure before the tensile strength values were reduced to 2/3rd of the initial. he present study suggested that the addition of antioxidants Good- rite, Anox, and Alkanox can improve the mechanical strength, ilm’s life, efectiveness, and stability and they are suitable to be incorporated in LDPE for commercial greenhouse ilms. 1. Introduction Greenhouses are known to provide most suitable conditions for production as the crops are being controlled and looked ater under suitably controlled environment, that is, by maintaining basic requirements for agriculture, for example, water, fertilizers, seeds, and plant protection chemicals. It is known that greenhouses are covered with transparent material that transmits visible light (400–700 nm), which is the major source of energy for photosynthesis [1]. In the last decades, the increased research towards greenhouses has signiicantly increased the involvement of plastics for use as a cover material [2]. Low-density poly ethylene (LDPE), being of light weight, transparent, economical, and of robust mechanical strength, has dominated the use of plastic ilms as greenhouse covering materials. However the greenhouse materials are subjected to numerous environmental factors that lead to chemical and/or physical degradation. It is well depicted in literature that degradation of LDPE is enhanced by UV radiation which transfers its energy to polymer molecules causing them to be energized and subject to oxidation [3]. Researchers have aimed to enhance the stability of LDPE ilms to make it more efective for greenhouse cover and a number of antioxidants and UV stabilizers have been reported in the literature [4–6]. Mashael [7] studied the efect of talc (10%) with PP and reported enhanced stress at break, elongation at break, and Young’s modulus. Xue et al. [8] developed aspen iber-polypropylene composites and studied mechanical properties at 4 ∘ C and 40 ∘ C. hey reported increase in tensile moduli, lexural moduli, and lexural strength as the wood iber content increased in the composites. he tensile strength decreased as the iber content increased. Hindawi Publishing Corporation International Journal of Polymer Science Volume 2014, Article ID 543930, 5 pages http://dx.doi.org/10.1155/2014/543930