Study On DTBP Initiated Mah Onto Isotactic Polybutene-1and Its Applications

Maleic Anhydride（MAH）/Styrene（St） multi-monomer grafting onto isotacticpolybutene-1（iPB-1） was prepared using Butyl Peroxide（DTBP） as the initiator in theHaake mixer. The influence of reaction temperature、 rotor speed、 initiatorcontent、monomer and co-monomer content on grafting ratio and Melt FlowRate（MFR） was investigated respectively. The results showed that temperature and rotorspeed had a little effect on grafting ratio and Melt Flow Rate（MFR） in the range of160℃-200℃and50r/min-90r/min. Increase of the initiator content will improve thegraft ratio to some extent, but excessive initiator can cause severe degradation; as acomonomer, styrene can remarkably enhance the grafting ratio and when St contentwas high, it can effectively depress the degradation of iPB.Compared with iPB, the mechanical properties of iPB-g-MAH with grafting ratiowas1.5%, melt flow rate was13.3g/10min remained almost unchanged. The FTIRresults showed the existence of （MAH-co-St） side chain can greatly accelerate thecrystal formâ…¡to formâ… transformation rate of iPB and the transformation rateincreases with increasing grafting degree. The DSC analysis results showed theexistence of （MAH-co-St） side chain increased crystallization temperature anddecreased crystallinity of iPB; polarizing microscope results showed that after graftingMAH onto Polybutene-1, crystallite dimension was smaller and the nucleation densityof iPB increased.The effects of iPB-g-MAH as the carrier of CaCO₃and modifying PA6wereinvestigated. The results showed that compared with iPB, the dispersity of CaCO₃among iPB-g-MAH was more uniform and the mutual combination between them wasmuch stronger. The mechanical properties of PP/iPB-g-MAH/CaCO₃system, especially the impact strength were better than PP/iPB/CaCO₃system.The rheologicalproperties of PP/iPB-g-MAH/CaCO₃system were obviously better thanPP/iPB/CaCO₃system. In the case of modifying PA6, it has been proved that themechanical properties of PA6modified by iPB-g-MAH were much better than that ofmodified by iPB; In the PA6/iPB-g-MAH blend, the adhesion between the two phaseswas so strong that the native crystallization peak temperature of iPB-g-MAHdisappeard. At the meantime, the interface of two phases blurred and dipersity ofiPB-g-MAH in the PA6matrix was improved.