Design And Synthesis Of Antistatic Agents And Their Effect On The Properties Of Polypropylene

Polypropylene（PP）is widely used in automotive,home appliances,packaging,medical and building materials applications due to its advantages of good heat resistance,chemical resistance,creep resistance,ease of processing and low price,and has become the second largest plastic in the world.However,PP is a typical insulating material,which very easy to generates static electricity due to friction or contact,bringing great inconvenience to production safety and daily life,and even cause fires and explosions in serious cases,which largely limits the scope of the application of PP.Therefore,the development of PP materials with antistatic properties is of great significance to broaden the scope of its application.In this thesis,two antistatic agents,N,N’-dihexadecyl-N,N,N’,N’-tetramethyl-N,N’-ethanediyl-di-ammonium bromide（GS）and poly（isopentenyl polyoxyethylene ether-co-（3-carboxyacryloyloxyethyl）dimethyl allyl aminium chloride）（TMQ）,were prepared by quaternization,copolymerization and esterification reactions.They were added to PP separately to study their effects on the antistatic properties,mechanical properties,melt and crystallization properties of PP,specifically as follows:（1）Antistatic modification of PP with GS as antistatic agent.The results show that after adding GS to PP,compared to pure PP,the surface resistivity（ρ_s）and tensile strength of modified PP are decreasing,the notched impact strength is increased firstly after declining,and the melt index is fluctuating and rising.When 12 wt%GS is added,theρ_s of PP is reduced by nearly 4 orders of magnitude,already with excellent antistatic properties,the tensile strength is reduced by 30.5%and the notched impact strength and melt index are increased by 137%and 447%,respectively.The results of washing resistance,durability and relative humidity change tests of antistatic properties show that the washing resistance and durability of antistatic properties of PP/GS materials are average,the relative humidity change has a greater impact on their antistatic performance,and the addition of GS has a smaller impact on the thermal stability of PP,which does not affect on PP processing and daily use.scanning e l e c t r o n m i c r o s c o p y（SEM）results show that the compatibility with PP decreases as the amount of GS added increases.Non-isothermal crystallization kinetic studies showed that the addition of GS reduces the crystallization peak temperature（T_p）,increased the half crystallization time(t_1/2)and reduced the crystallization activation energy（?E）.（2）Antistatic modification of PP with TMQ as antistatic agent.The results show that with the increase of TMQ content,theρ_s of PP show a decreasing trend,the tensile strength and notched impact strength first increase and then decrease,and the melt index shows an increasing trend.When 15 wt%of TMQ is added,ρ_s is reduced by almost 5 orders of magnitude,tensile strength is reduced by 38.6%and notched impact strength and melt index are improved by357%and 991%,respectively.The results of washing resistance,durability and relative humidity change tests of antistatic properties show that the washing resistance and durability of antistatic properties of PP/TMQ materials have excellent performance,and that relative humidity variation has little effect on its antistatic properties.And TMQ has little effect on the thermal stability of PP,which is not as stable as PP/GS materials,but does not affect on the normal processing and daily use of PP.SEM results show that too much TMQ is added,destroying its compatibility with PP.Non-isothermal crystallization kinetic studies showed that the addition of TMQ increased T_p,with a slight increase in t_1/2 and an increase in?E.