Identification of PP and PE for screen changer
Polyethylene for screen changer and polypropylene are the most commonly used Olefin Plastics. Polybutene -1 and poly 4- methyl amyl -1 are also used. Some copolymers of ethylene and ethylene and polyisobutene used as gaskets are also important polyolefin plastics. The simplest way to identify these plastics is by infrared spectroscopy. But some information can also be obtained from the melting temperature range.
The moderator said: Polyethylene (density related) 105~130 degrees C polypropylene 160~170 degrees C polybutene 120~135 centigrade poly 4- methylolefin -1 is greater than 240 degrees C
The reaction between these pyrolytic gases and mercuric oxide is different from each other. Therefore, first, the filter paper is soaked with 0.5 grams of sulfuric acid containing yellow mercury oxide (1.5 ml of concentrated sulfuric acid in 8 ml water), then a small amount of dry sample is put in the cracking tube, and the pipe mouth is covered with the filter paper and heated. If the steam makes a golden spot on the filter paper, it suggests that these plastics may contain polyisobutylene, butyl rubber for screen changer, and polypropylene (a small number of people will be able to show color after a few minutes). Polyethylene does not react. Natural rubber, nitrile butadiene rubber and polybutadiene produce brown spots. Polyethylene and polypropylene produce wax products during pyrolysis. Polyethylene is odorant like paraffin, while polypropylene has a slightly aromatic fragrance.