超声引发马来酸酐接枝HDPE、LLDPE和EPDM研究

MELT GRAFTING OF MALEIC ANHYDRIDE ONTO HDPE, LLDPE AND EPDM THROUGH ULTRASONIC INITIATION

在超声挤出反应装置中 ,研究了超声引发作用下马来酸酐 (MAH)与 HDPE、LLDPE及 EPDM的熔融接枝反应。通过化学滴定法、红外光谱法、特性粘度法和熔体流动速率 (MFR)测定法等 ,探讨了超声强度、体系组成及温度条件对接枝产物的性能及结构的影响。结果表明 ,超声振动能引起接枝产物粘均分子量明显下降和接枝率的明显上升 ,接枝率和熔体流动速率 (MFR)取决于体系中的超声强度、MAH含量及接枝温度。通过调控可制得具有较高接枝率、较好熔体流动性和凝胶含量≤ 0 .7%的 HD-PE- g- MAH(接枝率≥ 0 .6 % ,MFR=0 .5 g/ 10 min～ 2 .0 g/ 10 min)、L LDPE- g- MAH(接枝率≥0 .4 5 % ,MFR=4 g/ 10 min～ 7g/ 10 min)和 EPDM- g- MAH(接枝率≥ 0 .4 5 % ,MFR=0 .2 g/ 10 min)产物。与采用过氧类引发剂引发接枝比较 。

Grafting of maleic anhydride (MAH) onto high density polyethylene (HDPE), linearly low density polyethylene (LLDPE) and EPDM performed in melt state through ultrasonic initiation was studied. The effect of sonic intensity on the amount of grafted MAH, viscosity average molecular weight and melt flow index of the grafted product was investigated. The results show that the ultrasonic wave can obviously decrease the molecular weight of the grafted product and increase the amount of MAH grafted. The percentage of grafting of HDPE g MAH amounts to 0.6% , its melt flow index is between 0.5 g/10 min~ 2.0 g/10 min, the percentage of grafting of LLDPE g MAH and EPDM g MAH reaches to 0.45% , their melt flow indexes are between 0.5 g/10 min~ 2.0 g/10 min and between 4 g/10 min^7 g/10 min respectively, depends upon ultrasonic intensity, MAH content and grafting temperature. In all cases the gel content of the grafted products is less than 0.7% . Compared with the method of peroxide initiation, this method is easily controlled.