Surface and bulk oxidation of low-density polyethylene under UV-irradiation

Giesse, Ralf; Paoli, Marco-Aurélio De

doi:10.1016/0141-3910(88)90048-1

Cited by 20 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The degradation process for polyethylene is similar to other hydrocarbon polymers, whereby carbon bonds are broken, forming free radicals that react with oxygen and result in stable carbonyl groups [50].…”

Section: Photodegradation/uv Effectsmentioning

confidence: 99%

Polyethylene encapsulatin of nitrate salt wastes: Waste form stability, process scale-up, and economics

Kalb¹,

Heiser²,

Colombo³

1991

View full text Add to dashboard Cite

A polyethylene encapsulation system for treatment of low-level radioactive, hazardous, and mixed wastes has been developed at Brookhaven National Laboratory. Polyethylene has several advantages compared with conventional solidification/stabilization materials such as hydraulic cements. Waste can be encapsulated with greater efficiency (i.e., more waste encapsulated per drum) and with better waste form performance than is possible with hydraulic cement. The properties of polyethylene relevant to its long-term durability in storage and disposal environments are reviewed. Response to specific potential failure mechanisms including biodegradation, radiation, chemical attack, flammability, environmental stress cracking, and photodegradation are examined. These data are supported by results from extensive waste form performance testing including compressive yield strength, water immersion, thermal cycling, teachability of radioactive and hazardous species, irradiation, biodegradation, and flammability. The bench-scale process has been successfully tested for application with a number of specific "problem" waste streams including nitrate salts, sludges, incinerator ash, reactor-generated evaporator concentrates (sodium sulfate and boric acid), and ion exchange resins. A production-scale technology demonstration of polyethylene encapsulation of nitrate salt waste, sponsored by the Department of Energy (DOE), Office of Technology Development (OTD), Division of Demonstration, Testing and Evaluation (DT&E) is planned in conjunction with Rocky Flats Plant. In support of the technology demonstration, a scale-up feasibility test was conducted by processing simulated nitrate salt waste with a production-scale extrusion system. Output rates in excess of 454 kg/hr (1000 lb/hr) were achieved, ana process data were in close agreement with bench-scale parameters. Quality assurance and performance testing of the resulting waste form confirmed scale-up feasibility. Use of this system at Rocky Flats Plant can result in over 70% fewer drums processed and shipped for disposal, compared with optimal cement formulations. Based on the current Rocky Flats production of about 1 x 10 6 kg (2.2 x 10 6 lbs) of nitrate salt per year, polyethylene encapsulation can yield an estimated annual savings between $1.5 million and $2.7 million, compared with conventional hydraulic cement systems.

show abstract

Section: Photodegradation/uv Effectsmentioning

confidence: 99%

Polyethylene encapsulatin of nitrate salt wastes: Waste form stability, process scale-up, and economics

Kalb¹,

Heiser²,

Colombo³

1991

View full text Add to dashboard Cite

show abstract

“…Unfortunately, the heterogeneous nature of photodegradation complicates the determination of the applicable rate constants in the weathering of bulk polymer samples [73][74][75]. The progression of polymer degradation can be followed various chemical, physical and mechanical methods [24,71] including differential scanning calorimetry (DSC), thermogravimetric analysis (TG) [20], gel permeation chromatography (GPC) [76,77], X-ray photo-electron spectroscopy (XPS), chemiluminescence (CL) [78], Fourier transform infrared spectroscopy (FTIR) [26,79], oxygen uptake [80], CO 2 evolution studies [81,82] and mechanical testing [24,26,83].…”

Section: Polymer Photodegradationmentioning

confidence: 99%

Mn2Al-LDH- and Co2Al-LDH-stearate as photodegradants for LDPE film

Magagula

Nhlapo

Focke

2009

Polymer Degradation and Stability

View full text Add to dashboard Cite

The layered double hydroxides (LDH) Mn 2 Al-LDH-stearate and Co 2 Al-LDH-stearate were prepared by a surfactant-assisted intercalation of the corresponding precursor LDH-CO 3 forms.These compounds were evaluated as potential photodegradant additives in low density polyethylene films with a thickness of ca. 40 mm. They were incorporated into blown polyethylene films via a 10% masterbatch. The films were subjected to accelerated ageing in a QUV weatherometer. The machine was fitted with A320 lamps and operated on a dry cycle at 63 C and an irradiance of 0.67 W/m 2 . It was found that 100 h of QUV exposure was sufficient to cause mechanical embrittlement of films containing as little as 0.1% of either active.

show abstract

“…The tested physical and mechanical properties of CLPE were altered slightly by the PMPC grafting, as shown in Figures . Most previous studies have assumed that photoinduced polymerization is a surface restricted phenomenon . However, in reality, the changes (i.e., cross‐linking and chain scission) of the polymer structure under UV radiation can result in changes to the bulk physical and mechanical properties (swelling ratio, cross‐link density, and tensile‐ and small punch‐tests properties) of thin test specimens, such as those with a thickness of 0.5–2.0 mm that were used in this study.…”

Section: Discussionmentioning

confidence: 99%

Effect of UV‐irradiation intensity on graft polymerization of 2‐methacryloyloxyethyl phosphorylcholine on orthopedic bearing substrate

Kyomoto

Moro

Yamane

et al. 2013

J Biomedical Materials Res

View full text Add to dashboard Cite

Photoinduced grafting of 2-methacryloyloxyethyl phosphorylcholine (MPC) onto cross-linked polyethylene (CLPE) was investigated for its ability to reduce the wear of orthopedic bearings. We investigated the effect of UV-irradiation intensity on the extent of poly(MPC) (PMPC) grafting, and found that it increased with increasing intensity up to 7.5 mW/cm(2), and the remained fairly constant. It was found to be extremely important to carefully control the UV intensity, as at higher values, a PMPC gel formed via homopolymerization of the MPC, resulting in the formation of cracks at the interface of the PMPC layer and the CLPE substrate. When the CLPE was exposed to UV-irradiation during the graft polymerization process, some of its physical and mechanical properties were slightly changed due to cross-linking and scission effects in the surface region; however, the results of all of the tests exceed the lower limits of the ASTM standards. Modification of the CLPE surface with the hydrophilic PMPC layer increased lubrication to levels that match articular cartilage. The highly hydrated thin PMPC films mimicked the native cartilage extracellular matrix that covers synovial joint surface, acting as an extremely efficient lubricant, and providing high-wear resistance.

show abstract

Surface and bulk oxidation of low-density polyethylene under UV-irradiation

Cited by 20 publications

References 6 publications

Polyethylene encapsulatin of nitrate salt wastes: Waste form stability, process scale-up, and economics

Polyethylene encapsulatin of nitrate salt wastes: Waste form stability, process scale-up, and economics

Mn2Al-LDH- and Co2Al-LDH-stearate as photodegradants for LDPE film

Effect of UV‐irradiation intensity on graft polymerization of 2‐methacryloyloxyethyl phosphorylcholine on orthopedic bearing substrate

Contact Info

Product

Resources

About