Ozone Induced Reactions Adopted For Making High Performance Polymers From Commodity Polymers

Ozonization is a "green"technology for making high performance polymeric materials. Through ozonization, some oxygen containing polar groups are introduced on the molecular chains of non-polar commodity polymers, a lot of high performance materials can be made by blending them with some polar materials. Besides, the flow behavior of polymer can be improved through ozone induced degradation, the degradated product can be used as flow promoter used for improving the processibility of difficult processed polymers. Ozoniztion is simple, clean and efficient to industrial application. In this paper, HDPE, UHMWPE, PC and PA6 as well as HDPE/STC, UHMWPE/talcum, PC/POE, PC/POE/ wollastonite and PA6/SEBS composites are selected to study the mechanism and possibility for making high performance polymers from these commodity polymers. The experimental results show that higher ozone concentration, higher ambient temperature or in presence of ultraviolet can accelerate the rate of ozonization reaction of HDPE. Through ozonization, some oxygen containing polar groups are introduced on the molecular chains of HDPE, the carboxylic groups are main oxidation product. The dispersion of STC in ozonized HDPE matrix is improved, the interfacial adhesion between ozonized HDPE and STC is enhanced. Compared with untreated HDPE/STC (60/40) blend, the yield and notched impact strength of ozonized HDPE/STC (60/40) blend are increased to 29.5 MPa and 13.3 kJ/m2 respectively from 27.0 MPa and 2.8 kJ/m2. The yield and notched impact strength will be further increased to 30.7 MPa and 32.4 kJ/m2 in case the ozonized HDPE is blended with STC pretreated with silane coupling agent. The ozonized HDPE/STC (60/40) blend flows stably in high shear rate region. Compared with untreated UHMWPE, the melt flow rate of 120 minutes ozonized UHMWPE increases from 0 to 0.28g/10min. The impact strength of 120 minutes ozonized UHMWPE keeps above 140kJ/m2 and Young's modulus rises to 999MPa, the untreated UHMWPE is 513MPa. The melt flow rate of 120 minutes ozonized UHMWPE/talcum (90/10) blend can be further improved to 0.31g/10min, the impact strength still keeps above 140kJ/m2, Young's modulus rises to 1268MPa. The properties of PC/POE blend can be remarkably improved after blending it with certain amount of ozonized POE. Compared with PC, the impact strength of PC/POE(90/10) blend increases from 24.6 kJ/m2 to 72.5 kJ/m2, the rheological behavior gets better. After immersion in acetone 4 hours and 80℃hot water 48 hours, the impact strength of PC decreases to 3.2 kJ/m2 and 12.0 kJ/m2 respectively, the PC/120 minutes ozonized POE(90/10) blend decreases to 43.7 kJ/m2 and 69.2 kJ/m2 only. Through filling with 10% ozonized POE, the resistance to chemical corrosion and mechanical property of PC/wollastonite(85/15) blend are improved also. Blending with 60 minutes ozonized SEBS, the impact strength of PA6/SEBS(80/20) blend increases to 110 kJ/m2 (at 23℃) and 16.7 kJ/m2 (at -25℃) respectively from 13.3 kJ/m2 and 8.1 kJ/m2. Compared with PA6, the processibility of PA6/SEBS(80/20) blend are improved also.