Polypropylene film exposure

Figure 1. ESR spectra of P00 radicals formed during exposure of polypropylene films to (——) ozone and (—) ozone and UV light (LI).

Figure 2. Kinetic curve of POOH groups formation in polypropylene film after 10 hours exposure to ozone.

Table 1. Change in the wettability of polypropylene film after exposure to ozone and ozone-UV irradiation...

M.C. Branch, N. Sullivan, M. Ulsh, and M. Strobel. Surface Modification of Polypropylene Films by Exposure to Laminar, Premixed Methane-Air Flames. Proc. Combust. Inst., 27 2807-2813,1998. 

Table 5 Effect of processing history (190 °C) on the light stability of polypropylene films (300 nm) containing Irganox 1010 and hindered-piperidine additivies (0.1% each). Exposure unit microscal—lOOOW...

Trubiroha [43] reported an action spectrum for development of carbonyl groups (as measured by the change in absorbance at 5.8 microns) of unstabilized polyethylene and polypropylene films. A measurable effect after 1 MJ/sqm of radiant exposure was obtained only for X = 380 nm between 280 and 380 nm the absorption changed logarithmically with wavelength of irradiation. 

M. Campomanes Santana. Comparative assessment of degradation in aqueous medium of polypropylene films doped with metal free (experimental) and transition metal containing (commercial) pro-oxidant/pro-degradant additives after exposure to controlled UV radiation . Polym. Degrad. Stab., 120, 186-192 (2015)... 

Whilst all the polymers with intrinsic chromophores are inherently sensitive to degradation, at least some are regarded as relatively stable materials, able to resist solar exposure for long periods. In contrast, polymers like the polyolefins and the hydrocarbon rubbers have remarkably poor lifetimes when exposed to solar light. Unstabilized polypropylene film, for example, has... 

Polypropylene. Polypropylene (PP) is used ia packagiag appHcations as films and ia rigid containers. Battery cases could be considered another packagiag appHcation. Dead batteries are often collected at the poiat of sale of new batteries. In the U.S., some states have laws mandating this. Lead, acid, and plastics, particularly PP from battery casiags is recovered and recycled (3). Care must be taken to limit worker exposure to lead duting this process (44). PP is also recovered from bale wrap and other PP fabrics used for wrappiag ia the textile iadustry and from other containers (45). 

Additive-free film samples of isotactic polypropylene (iPP, 30pm Himont Profax resin) and polyethylenes (LLDPE, 120ym, linear low density DuPont Sclair resin, and UHMW-PE, 120wm, ultra high molecular weight, high density Himont LSR 5641-1B resin) were oxidized by exposure in air to y-radiation (AECL Gamma Cell 220, 1.0... 

P.R.170 is not always heat stable enough to allow application in polyolefins. In HDPE systems formulated at 1/3 SD, the pigment tolerates exposure to 220 to 240°C for one minute. Its tinctorial strength, on the other hand, is excellent. P.R.170 is also occasionally used in polypropylene and polyacrylonitrile spin dyeing in the latter medium, it satisfies the specifications of the clothing and home textiles industries. Besides, P.R.170 lends color to viscose rayon and viscose cellulose it is used for the mass coloration of semisynthetic fibers made of cellulose last but not least, it colors yarns, fibers, and films made of secondary acetate. 

Modifications of polymer surfaces by exposure to electrical plasmas and discharges have also been subjected to XPS examination in several recent articles (4, , 7). An example is the plasma oxidation of polyethylene, polypropylene and polystyrene in a radiofrequency inductively coupled system ( ). Figure 14 shows the Cls and 01s spectra of a polyethylene film after... 

Dehydrated calcium pimelate is added (between 0.01 and 0.5 wt %) as the nucleating agent to isotactic polypropylene to produce the (3 modification of iPP [63]. Following molding between two glass plates at 220°C thin films of the polymer are isothermally crystallized at 140°C-143°C in a microscopy hot stage. After the hedritic structures develop, the samples are quenched to room temperature. Prior to AFM examination, the specimens are etched with a 1% solution of potassium permanganate in a mixture of sulfuric and orthophosphoric acid [64, 65]. This procedure is described in detail in the literature Caution consult the literature for safety precautions ) and helps to remove preferentially amorphous phase of PP [64]. Thus, unlike in the many other examples discussed in Sect. 3.2, here the interior of a specimen is analyzed after its exposure. 

Seawater Suspensions of Prudhoe Bay Crude Oil. Continuous-flow suspensions of Prudhoe Bay Crude (PBC) were generated in an experimental apparatus described previously (16). The initial suspensions were diluted to the desired concentrations with additional seawater and were then sent directly to exposure tanks. In some cases, the initial oil suspension was filtered through 100-/un polypropylene filters prior to use. The filtered suspensions were necessary to avoid buildup of oil films on the exposure apparatus in studies where simulated tidal cycles were employed. 

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