Received: 28 May 2008, Revised: 14 August 2008, Accepted: 2 September 2008, Published online in Wiley InterScience: 21 January 2009 Role of polyethylene-graft-glycidyl methacrylate compatibilizer on the biodegradation of poly(e-caprolactone)/ cellulose acetate blends D. S. Rosa a * , M. A. G. Bardi a , C. G. F. Guedes a and D. A. Angelis b Biodegradable polymers provide an attractive solution to reduce environmental pollution caused by the accumu- lation of plastic waste in landfills. In this study, the effect of polyethylene-graft-glycidyl methacrylate (PE-g-GMA) on the biodegradation of blends of poly(e-caprolactone) (PCL) and cellulose acetate (CA) (80/20, 60/40, 40/60, and 20/80 PCL/CA, w/w) was assessed by mass retention, tensile strength, and morphological properties. The principal fungal strains present in the soil after biodegradation were also identified. PCL and the blends containing 60% and 80% PCL showed greater mass loss and superficial change in simulated soil. PE-g-GMA increased the tensile strength retention during 3 months of aging in simulated soil. Scanning electron microscopy (SEM) indicated that pure PCL was more porous, which enhanced the hydrolysis and biodegradation of PCL. PE-g-GMA decreased the mass loss of the polymers, possibly by enhancing the interaction between PCL and CA, with the formation of hydrogen bonds between the carbonyl groups of PCL and the hydroxyl groups of CA. This effect was marked in blends with >40% PCL. Microbiological analysis revealed the presence of several species of fungi in the soil. Copyright ß 2009 John Wiley & Sons, Ltd. Keywords: biodegradation; cellulose acetate; poly(e-caprolactone); polyethylene-graft-glycidyl methacrylate; polymer blends INTRODUCTION The useful life of most synthetic polymers is short (less than 2 years in many cases), in contrast to their elevated resistance to degradation. This limited degradability is the target of much criticism because of the deleterious effects of plastic waste accumulation in the environment. [1] One solution to this problem is to collect, separate, and recycle some of these materials. [2] However, the difficulties associated with the selection and separation of plastic waste have generally made this process unfeasible. [3] An alternative solution that has been extensively investigated [4–11] is to use biodegradable polymers that have shorter half-life in the environment, under appropriate conditions of moisture, temperature, and oxygen availability, [12] which depend on the structure characteristic, molecular weight, and crystallinity of the polymers among others. The American Society for Testing and Materials [13] defines a biodegradable material as one that can be completely (bio)assimilated by microorganisms that transform biomaterials into elements that are not harmful to nature, in which larger living organisms can play a part but the most important organisms are bacteria and fungi. However, the extent of biodegradation is highly influenced by the composition of the material, including its carbon content and the presence of additives, plasticizers, and compatibilizers. [14] Thus, Chiellini et al. [7] say that boundary conditions related to the framework under which the biodegradation assessment is undertaken have to be taken into account, and specifically well-defined. For example, poly(e-caprolactone) (PCL), a synthetic aliphatic poly- ester made from the ring opening polymerization of e-caprolactone, is a biodegradable polymer. However, the prohibitive cost of producing PCL has led to the development of less expensive degradable polymeric materials by blending PCL with polymers such as poly(3-hydroxybutyrate-co-hydroxy- valerate) (PHBV), [15] PHB, [16–18] poly(vinyl chloride), [19–22] chito- san, [23–26] starch [27–31] and cellulose acetate (CA). [32] Rosa et al. (www.interscience.wiley.com) DOI: 10.1002/pat.1302 Research Article * Correspondence to: D. S. Rosa, Laborato ´rio de Polı ´meros Biodegrada ´veis e Soluc ¸o ˜es Ambientais, Programa de Po ´s-Graduac ¸a ˜o Stricto Sensu em Engen- haria e Cie ˆncia dos Materiais (PPG-ECM), Universidade Sa ˜o Francisco, Rua Alexandre Rodrigues Barbosa, No 45, Centro, CEP 13251-900, Itatiba, SP, Brazil. E-mail: derval.rosa@saofrancisco.edu.br; dervalrosa@yahoo.com.br a D. S. Rosa, M. A. G. Bardi, C. G. F. Guedes Laborato ´rio de Polı ´meros Biodegrada ´veis e Soluc ¸o ˜es Ambientais, Programa de Po ´s-Graduac ¸a ˜o Stricto Sensu em Engenharia e Cie ˆncia dos Materiais (PPG-ECM), Universidade Sa ˜o Francisco, Rua Alexandre Rodrigues Barbosa, No 45, Centro, CEP 13251-900, Itatiba, SP, Brazil b D. A. Angelis Departamento de Bioquı ´mica e Microbiologia, Universidade Estadual Paulista Ju ´lio de Mesquita Filho, Av. 24-A, 1515, Bela Vista, CEP 13506-900, Rio Claro, SP, Brazil Contract/grant sponsor: CNPq; contract/grant numbers: 304577/2004-9; 471177-2006-7. Contract/grant sponsor: FAPESP; contract/grant number: 04/13359-8. Contract/grant sponsor: Universidade Sa ˜o Francisco. Polym. Adv. Technol. 2009, 20 863–870 Copyright ß 2009 John Wiley & Sons, Ltd. 863