Polyethylene degradable films

A new large pit was constructed at the Agronomy-Agricultural Engineering Research Center with two thicknesses of 6-mil black polyethylene plastic film as a liner. More intensive research was conducted in 56 plastic mlniplts to evaluate chemical interactions, degradation, and biological activity (2). 

The most fundamental work on polyethylene degradation is being done by A. C. Albertsson in Sweden(27,28,29,30,31) using elegant science with labelled polymers to measure the rate and quantity of carbon dioxide evolution from buried high and low density polyethylene films. Degradation occurs at about... 

Eco Film is designed to replace non-degradable as well as starch and polyethylene-based films. Eco Film is available in standard lengths of 91.4 cm and 122 cm rolls as well as a variety of custom sizes and forms. 

Applications of Environmental Degradation of Polyethylene/TDPA Films... 

Degradable Low-Density Polyethylene (LDPE) Films. Typical xenon arc embrittlement times for unstabilized low-density polyethylene are l600-2UOO hrs. The controls chosen for this research are listed in Table II the thin LDPE garment bag embrittled in 1820 hr and the EcoPlastics LDPE control became brittle after 2075 hr xenon irradiation. The thin garment bag was not brittle, as determined by a fold test, after 18 months outdoor exposure. The Dupont "Sclair" LDPE control listed in Table II was unusual since it had short embrittlement times of 1175 hr in the Weather-Ometer and 6.5 months outdoors. This film was used as a yardstick to measure the Degradable LDPE films since a Degradable Plastic should not last more than 6 months, perhaps less, outdoors and 1200 hr in the xenon arc Weather-Ometer. 

Polylactone and poly(vinyl alcohol) films are readily degraded by soil microorganisms, whereas the addition of iron or calcium accelerated the breakdown of polyethylene. Degradable mulches should break down into small brittle pieces which pass through harvesting machinery without difficulty, and do not interfere with subsequent planting. Effective funaigant mulches require reduced-porosity films which reduce the escape of volatile chemicals, i.e. nematocides, insecticides, herbicides, etc., and therefore allow for lower application rates. 

A. Cord, M. Sudhakar, E. Chiellini, Assessment of the whole environmental degradation of oxo-biodegradable linear low density polyethylene (LLDPE) films designed for mulching applicadons. J. Polym. Environ. 20, 1018 (2012)... 

Degradability is neither magic nor a quick fix. For example, polyethylene (PE) film bags that contain cornstarch as an additive to further biodegradability cause the starch to become carbon dioxide and water— but the PE remains, simply in a different form. 

It is clear that the accumulation of nickel in various parts of the plant remains constant within experimental limits, whatever the concentration of nickel in the soil. Furthermore, It can be calculated that in the worst case scenario , it would take 500 years to increase the nickel content of soil using typical nickel contents of degradable polyethylene mulching films by 1 ppm [25],... 

Polymer Degradation and Stability 73,No.l,2001,p.69-74 EXAMINATION OF A LOW DENSITY POLYETHYLENE (LDPE) FILM AFTER 15 YEARS OF SERVICE AS AN AIR AND WATER BARRIER... 

The blending of polymeric organic carbonyl compounds, e.g., ethylene/carbon monoxide copolymer, with the parent polymer, e.g., polyethylene, gives a plastic film material that degrades within 3 months. 

Figure 71 compares the 2,000-1,000 cm-1 FTIR spectral region for the heat seal layers of the "good" and "bad" films, and the center opaque polyethylene layer for the "bad" film. Of particular interest is the carbonyl region between approximately 1,800 and 1,650 cm-1. The two heat seal surface spectra show mainly the vinyl acetate ester carbonyl band at 1,740 cm-1. For the middle polyethylene layer of the "bad" film, the shape and position of the carbonyl band is consistent with oxidative degradation of polyethylene. The peak maximum at... 

Conclusions. Based on the results of SEM, FTIR spectroscopy, and TGA analyses performed on the "good" and "bad" samples of white packaging film, the brittleness problem reported for the packages appears to have been caused primarily by degradation of the central opaque polyethylene layer. 

---