CH2一CH2Polyethylene. This polymer has one of the simplest molecularstructures and is at present the largest tonnage plasticproduced commercially inmaterial, having first been1939.. It is a waxy solid that is relatively low in cost, easilyprocessed, and shows good chemical resistance
Polyethylene • This polymer has one of the simplest molecular structures and is at present the largest tonnage plastic material, having first been produced commercially in 1939. • It is a waxy solid that is relatively low in cost, easily processed, and shows good chemical resistance
PolyethyleneThe polymerization of ethylene is controlledby a catalytic process a very small numberof branches in the chain is obtained. it iscalled linear polyethylene, or HDPEE (high-density polyethylene).The polymerization of ethylene under high-pressure results in a certain number ofbranches in the chain. it iss called low-density polyethylene, or LDPE
Polyethylene The polymerization of ethylene is controlled by a catalytic process a very small number of branches in the chain is obtained. it is called linear polyethylene, or HDPE (highdensity polyethylene). The polymerization of ethylene under highpressure results in a certain number of branches in the chain. it is called lowdensity polyethylene, or LDPE
StructureAmoleculeof linearpolyethylene,orHDPEAmoleculeofbranchedpolyethylene,orLDPE
Structure
PolyethyleneThere are four different industrial routes to thepreparation of polyethylene, and they yield productshaving slightly different properties. The four routes are:High Pressure Processes,D1i)Ziegler Processes,(ili) The Phillips Process,(iv) The Standard Oil (Indiana) Process
Polyethylene There are four different industrial routes to the preparation of polyethylene, and they yield products having slightly different properties. The four routes are: (i) High Pressure Processes, (ii) Ziegler Processes, (iii) The Phillips Process, (iv) The Standard Oil (Indiana) Process
LowDensityPoly(ethylene)High Pressure Processes:pressures of 1000±3000 atm. and temperaturesof 80±300 C.Free-radicalinitiators, high-pressure processes tend to yield lower densitypoly ethylene, typically in the range0.915±0.945g/cm3
Low Density Poly(ethylene) ◼ High Pressure Processes: pressures of 1000±3000 atm. and temperatures of 80±300 ℃. Free-radical initiators, highpressure processes tend to yield lower density poly ethylene, typically in the range 0.915±0.945 g/cm3