Degradation agricultural mulches

Several years ago, Princeton Polymer Labs. contracted with a client to develop a degradable agricultural mulch film. A first generation additive system was developed and some 12,000 sq. ft. of polyethylene film containing the additive was tried out in 14 states in the U.S.A. Both black and clear films... 

Otey, F. H., Mark, A. M., Mehltretter, C. L., and Russell, C. R., 1974, Starch-based film for degradable agricultural mulch. Ind. Eng. Chem., Prod. Res. Develop. 13 90-92. Averous, L., Moro, L., Dole, P., and Fringant, C., 2000, Properties of thermoplastic blends starch-polycaprolactone. Polymer 41 4157-4167. 

Otey F, Mark A, Mehltretter C, Russell C, (1974) Starch-based film for degradable agricultural mulch , Ind. Eng. Chem. Prod. Res. Dev., vl3 90-95. 

A second generation, and far more effective photo-degrading additive system was later developed and extensive indoor and outdoor testing was done. With such an effective system it was obvious that its use could go much further than just agricultural mulch films. 

Realistic uses for Degradable Plastics include those applications where materials are used outdoors for a limited time only and it is not economically desirable to collect the residual materials after use. Examples are agricultural mulch, films and cordage, twine, etc. Another application is that of packaging which is stored and used indoors and discarded outdoors, in other words litter for which manual collection is not practicable. 

Ecoten LDPE embrittled in 2210 hrs in the Weather-Ometer and 11 months outdoors. This sample of Ecoten does not appear to be a satisfactory Degradable Plastic because of the high level of Ti02 added to the film. Clear Ecoten film without the titanium dioxide pigment was tested outdoors in Israel as agricultural mulch and found to embrittle in less than four months ( ). 

Otey, F. H, and Mark, A. M., 1976, Degradable starch-based agricultural mulch film, IJ.S. Patent 3,949,145... 

Lahalih, S. M., Akashah, S. A., and Al-Hajjar F. H., 1987, Development of degradable slow release multinutritional agricultural mulch film, Ind.Eng.ChemRes. 26 2366-2372... 

In conclusion, a solution to waste treatment by self-degradation of plastics has not been favored at least for the packaging industry. However, it has been successfully implemented for selected controlled-life plastics in agriculture (mulching). It is also a possible solution for marine debris, plastics in release control of fertilizers and pesticizers, biomedical applications, and diapers. Converting to polymers which are soluble in selected solvents may also permit some special treatment. 

Cole et al. [55] investigated the degradability of corn starch based PE and modeled the role of biodegradation by a (scalar) percolation theory. Based on these researches Archer Daniels-Midland (ADM) Company developed a technology to make starch-based plastics. These materials were proposed for applications such as agricultural mulch and disposable packaging. 

F.H. Otey et al. (1976) Degradable starch-based agricultural mulch film. 

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