Fluorinated polyolefines

The lap shear test involves measuring the adhesive shear strength between two surface fluorinated polyolefin sheet tokens that are adhesively secured with a reinforcement resin. The tokens are individually reinforced with steel backing plates to eliminate flexural distortion in the shear joint. Lap shear tests carried out with various reinforcing polyester-type resins, contrasting fluorination and oxyfluorination as surface treatment, are shown in Table 16.8. 

Flame retardants are often used in combination with anti-drip agents, which reduce the tendency of the material to form burning droplets in the event of fire (67). Fluorinated polyolefins are preferably used as anti-drip agents (22,67). 

A surface analysis technique that has the potential to detect structural chemical changes in polymer surfaces, including low-molecular weight material formation, is static SIMS. Its capabilities for characterizing polymers by virtue of their fingerprint spectrum nave been amply demonstrated in recent years (5 6). The technique is more surface sensitive than XPS and can detect structural differences, even in hydrocarbons (7). It is, therefore, highly complementary to XPS. Nevertheless, only very few applications to the study of modified polymer surfaces have been published. Among these are reports on SIMS analysis of flame-treated polypropylene and plasma-fluorinated polyolefin surfaces (8 9). 

Several poly(fluorinated olefins) are used in practice. These include poly(vinyl fluoride), poly(vinylidene fluoride), poly(trifluoroethylene), poly(tetrafluoroethylene), and other fluorinated polyolefins such as poly(perfluoro-heptene) or poly(perfluoro-propylene). Poly(vinyl fluoride) with the general formula [-CH2CHF-]n and CAS 24981-14-4 is less common than its chlorinated analog, but still has numerous practical applications, mainly in coatings. Upon heating, the polymer begins losing HF at about 350° C with formation of double bonds in the carbon chain. At about 450° C the backbone of the polymer... 

Finally, the poor solubility of fluorinated polyolefins can also be exemplified by the phase behavior of fluorinated polyisoprenes and polybutadienes in SC-CO2 (see Figure 13.3) [18], A pressure of 1000 bar and a temperature of 60°C were thus... 

XPS depth profiling can be done nondestructively, while SIMS one is destructive. Nevertheless, SIMS is, totally, more advantageous than XPS. In this paper, results from our studies on SIMS depth profiling will be surveyed they are applications to polymer blends, optical fibers, video tapes, and surface-fluorinated polyolefin films. 

Whereas PVA fleeces are used only in primary cells polyamide fleeces compete with polyolefin, preferably polypropylene fleeces. The latter are more stable at higher temperatures and do not contribute to electrolyte carbonation, but they wet only after a pretreatment either by fluorination [131] or by coating and crosslinking with hydrophilic substances (e.g., polyacrylic acid [132]) on the surface of the fiber. 

Treatment with fluorine/nitrogen mixtures (fluorination) increases the polar component of the surface energy initially, but longer treatment times result in a drop in both the polar component and the total surface energy24 25 (see Figure 16.3). At very long treatment times the surface energy ofthe treated surface can be lower than that of the polyolefin itself. 

Polyolefin containers, fluorine surface treatment of, 11 846 Polyolefin dust, 20 230 Polyolefin fibers, 11 224 24 614. See also Olefin fibers... 

Polyolefins, like their model compounds (alkanes), are unreactive molecules. When ignited in an abundance of oxygen, polyolefins bum and produce carbon dioxide and water. Fluorine reacts with polyolefins at room temperature with explosive violence, but iodine is unreactive even at elevated temperatures. 

These adhesives bond well with most plastics, other than the polyolefins and fluorinated polymers. 

---