Poly tube applications

Polyepichlorohydrin and poly(propylene oxide) rubbers have been discussed recently (82). World usage of polyepichlorohydrin rubber is 20-22 million pounds (9-10,000 metric tons) per year and has a growth rate of 7-8 percent per year. It is used mainly in the automotive industry, where advantage is taken of polyepichlorohydrin s excellent ability to withstand ozone and heat and its good air- and oil-permeability characteristics. Worldwide demand for poly(propylene oxide) rubber is about 1-2 million pounds (450-900 metric tons) per year. This rubber is effective in high-performance tubing applications that need both high-temperature resistance and the properties of natural rubber. Poly (propylene oxide) rubbers have upper use-temperature limits of 145°C, compared to 110°C for natural rubber. 

Poly(vinyl chloride) (PVC) has replaced leather in many of its applications PVC tubes and pipes are often used in place of copper. 

Poly(aryloxyphosphazene) elastomers can be cured with peroxides, sulfur and radiation. The resulting vulcanizates are resistant to attack by moisture and oils and have been found to have desirable characteristics for electrical insulation applications where fire safety is a concern (Table II) (12). Fire resistant, low smoke, closed cell foams with excellent properties (Table III) have also been developed from poly(aryloxyphosphazene) elastomers (13). Applications for these foams, which can be produced as either slabstock or tube stock, are being developed for military, aerospace and commercial uses. (See Table II and III.)... 

This explosive can be just poured into the bore hole if water is not present. It will work in a wet environment, but the longer the exposure to moisture, the less performance can be expected. The best application in a wet bore hole is to place the slurry in a poly ethylene tube or a trash bag to protect the explosive from the adverse affects of the water. 

Many of the first papers which discussed the use of (selective) CVD of tungsten for IC applications used conventional hot wall tube CVD reactors [Broadbent et al.44, Pauleau et al.45, Cheung47]. This type of reactor was and still is the workhorse in IC fabs. Excellent films such as TEOS based oxides, thermal silicon-nitride and poly-silicon can be grown in such equipment. Hot wall tube reactors are suitable for these films because such materials stick very well to quartz tubes and are quite transparent to IR radiation of the heating elements. Thus neither particle nor temperature control is a problem. One other major advantage is that high throughputs are typically obtained. 

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