Study On The Maleic MAH/VT Functional Modified Isotactic Polybutene-1

The maleic anhydride(MAH)/(VT)melt grafting of isotactic polybutene-1(iPB-1)was prepared(iPB-g-MAH-co-VT)in torque rhemeter using dicumyl peroxide(DCP)as an initiator and VT as comonomer.The effects of VT concentration,reaction temperature,DCP concentration,MAH concentration,and reaction time on the grafting degree(Gd),grafting efficiency(Ge),and melt flow rate(MFR)of the iPB-gMAH-co-VT were researched respectively.It is significantly that VT can improve the grafting degree,and when the reaction temperature was 180 centigrade degree,DCP and MAH concentration were 0.2 and 6 phr respectively,the ratio of VT and MAH was 1/1(mole ratio),the grafting degree was 3.12%.By measuring the contact Angle of the samples found that the surface polarity of iPB-g-MAH-co-VT increased with increasing grafting degree.DSC test results showed that the crystallization temperature(Tmc)of iPB-g-MAH-co-VT was higher than that of iPB-1 and the peak width was narrowed.What's more,with the increase of grafting degree,the melting temperature(Tm)and Tmc of iPB-g-MAH-co-VT increased and the peak width was gradually narrowed,which indicated that the grafted chain could significantly accelerate the crystallization rate of iPB-1.The study of non-isothermal crystallization showed that under the same cooling rate,with grafting degree of iPB-gMAH-co-VT increasing,initial crystallization temperature(Ti),peak crystallization temperature(Tp)and end of crystallization temperature(Te)higher than that of iPB-1,shifted to higher temperature and crystallization time that were less than that of iPB-1 decreased gradually.The results indicated that the increased grafting degree made crystallization rate of iPB-1 faster.With the increase of cooling rate,Ti,Tp and Te of iPB-1 and grafted samples shifted to lower temperature and crystallization time shortened,which resulted in the poor uniformity and perfection of crystal and faster crystallization rate.Study on non-isothermal crystallization kinetics of iPB-1 and grafted samples,the results showed a good linear relationship calculated by the methods of Ozawa and Mo.With the increase of grafting degree,the value of F(T)decreased which meaned the grafted chain could accelerate the crystallization rate.The activation energy of non-isothermal crystallization was calculated by Kissinger equation.The activation energy of iPB-1 was-72.85 KJ/mol that was higher than iPBg-MAH-co-VT.What's more,the increased grafting degree led to lower activation energy.The crystalline morphology of iPB-1 and grafted samples were observed by polarizing microscope.Compared to iPB-1,the number of nuclei of grafted samples increased obviously and the spherulite size decreased.Moreover,with grafting degree increasing,the number of nuclei increased and the grain refined.Muscovite powder/iPB-1 composites and Silica/i PB-1 composites were prepared by melt blending method and characterized by DSC and polarizing microscope.The polarizing microscope show that muscovite powder and silica has a certain influence on the crystallization of iPB-1.With muscovite powder and silica mass fraction increases the morphology of spherulite size changed to smaller.DSC data show that along with the muscovite powder and silica mass fraction increases the crystallization temperature of the composites decreased.The addition of the muscovite powder and silica reduces the crystallization rate of iPB-1.Muscovite powder and silica can not be used as the nucleating agent for the isotactic polybutene-1.