Study Of Grafting Modification And Its Adhesive Property Of HDPE

High density polyethylene(HDPE)is widely used as the plastic layer of metal-plastic composite materials with its extraordinary characteristics.However,there is no bond between the metal and HDPE becsuse polymer chains of HDPE were apolar.HDPE should be modified as polar materials.The grafting modification was a difficult reaction with low branching content of HDPE.It is difficult to obtain material with good adhesion by increasing of grafting rate.The adhesion of HDPE would be better when additives were used.The high-density polyethylene was graft-modified in the paper.HDPE-2911 was used as graft matrice.With DCP and BPO as a comparison of initiator,MAH as grafting monomer,white oil as dispersant,rosin resin,POM and St as additives HDPE was graft-modified.The reaction temperature,the screw speed,the dosage of initiator,the amount of grafting monomer,the amount of dispersant and the amount of additives were used as variables.The graft rate of product was quantitative analysis in the way of IR spctra.The main properties of samples were studied,including the grafting rate and gel content of grafted copolymer,the peel strength,melt flow rate,tensile properties,capillary rheological properties,crystallization behavior and softening point.The relation of the various properties and the reaction conditions was studied.When the reaction temperature was selected as the variable of melt grafting reaction,the product performance were tested With the increasing temperature,the grafting ratio and peel strength increased at first and then decreased When the temperature was 175?,the grafting ratio and peel strength displayed maximum value,the MFR,the softening point and the tensile property were better.The grafting products were easily machined and used.The IR spectra and grafting ratio test showed MAH were successfully grafted onto the HDPE chain.When the screw speed was selected as the variable of melt grafting reaction,it showed that the impacts on product performance were irregular,but it could be found that when the screw speed was 25r/min,the performance of the grafted product was excellent.When the temperature was 175?,the initiation efficiency of DCP was better than BPO.With the increase of DCP content,the grafting ratio and peel strength increased at first and then decreased,and the gel content increased.When the DCP content was 0.08phr,the adhesion was better.When the MAH content was selected as the variable,it showed that the grafting ratio increased at first and then decreased a little,the peel strength increased at first and then decreased,and the gel content increased,with the increase of MAH content.When the MAH content was 0.8phr,the adhesion was better.When the white oil content was selected as the variable,we found that the grafting ratio increased a little at first and then decreased,the MFR decreased,and peel strength increased at first and then decreased,with the increase of white oil content.When the white oil content was 0.8phr,the adhesion was better.It was also found that the use of the second monomer St was helpful to the increasing of grafting ratio.In order to improve the peel strength of the adhesive resin,rosin resin and POE was used in the formula.It was useful to increase the adhension with metal by the improving of the wettability.With the comparison and analyze,the optimum amount of rosin resin was found.The peel strength with aluminum sheet and steel sheet was good.POE also has a great influence on the peel strength of aluminum sheet and steel sheet.