融熔共混法制备HDPE-g-TMI接枝物的研究

以2,5-二甲基-2,5-双(叔丁基过氧基)己烷(DHBP)为引发剂,3-异丙基-α,α-二甲基苄基异氰酸酯(TMI)为接枝单体,苯乙烯(St)为共单体,与高密度聚乙烯(HDPE)在HAAKE熔体流变仪中熔融共混,制备HDPE-g-TMI接枝共混物,讨论在接枝反应过程中不同条件对TMI在HDPE上接枝率(TMI]g)的影响.研究发现:TMI成功接枝到HDPE分子链上;在熔融共混过程中,随着w(TMI)的增加TMI]g也逐渐增大,当w(TMI)为7.5%时,TMI]g达到最大值为0.101 2mmol/g;当w(DHBP)较少时(≤0.5%),其含量的增加对TMI]g影响不大,当w(DHBP)较高(0.5%)时,TMI]g与DHBP加入量呈线性关系增加;随着加工温度的升高,TMI]g先增加后下降,加工温度为180℃时,TMIg]达最大值为0.368 2mmol/g;共单体St的加入可以有效提高TMIg],当w(St)含量为7.5%时TMI]g达最高值为0.405 0mmol/g.

Preparation of HDPE-g-TMI graft copolymer by reactive blending method

HDPE was grafted with 3-isopropenyl-α,α-dimethylbenzene isocyanate（TMI） and comonomer styrene,using 2,5-dimethyl-2,5-die（tert-butylperoxy）-hexane（DHBP） as free-radical initiator in HAAKE torque rheometer,the effect of processing conditions on the grafting degree of TMI（g） were discussed in detail.The results showed that： TMI was grafted in HDPE chain successfully;g increased with the increasing of w（TMI） content,and g reached a maximum at 0.101 2 mmol/g when w（TMI） was 7.5%;The effect of increasing DHBP content on g was lightly when w（DHBP） content was less than 0.5%,but g increased along with the increasing of DHBP and when w（DHBP） was more than 0.5%,g increased first and then decreased along with the increasing of processing temperature,and g reached a maximum at 0.368 2 mmol/g when the temperature was 180 ℃.The comonomer St could greatly improved g,and g reached a maximum at 0.405 0 mmol/g when w（St） was 7.5%.