双端硅氢全氟聚醚-b-聚硅氧烷在丁腈橡胶中的性能

Properties of double-ended silohydroperfluoropolyether polysiloxane in nitrile rubber

以全氟聚醚烯丙基醚和3种双端含氢硅油(PSi-H)为原料,制备了3种双端硅氢全氟聚醚-b-聚硅氧烷(PFPE-b-PSi-H)减磨剂,然后添加到丁腈橡胶(NBR)中制备了改性NBR。采用FTIR和^(1)HNMR表征了PFPE-b-PSi-H的结构,并对改性NBR的磨损与摩擦系数、拉伸性能与硬度、DMA和TGA进行了测试。结果表明,当选用Si—H键中H的质量分数为0.115%的PSi-H时,所制备PFPE-b-PSi-2使改性NBR的性能达到较佳效果。与NBR相比,当PFPE-b-PSi-2含量为NBR质量的2.0%时,制备的改性NBR的阿克隆磨耗体积从0.250 cm^(3)降至0.125 cm^(3),静摩擦系数从2.589降至1.402,动摩擦系数从2.176降至1.209,拉伸强度从21.4 MPa提高到24.2 MPa,邵氏硬度A从81降至79度,玻璃化转变温度从1.7℃提高到5.7℃,损耗因子从0.73提高到0.78,10%热失重温度提高65℃,残炭率提高9.47%,表明该减磨剂能够降低NBR内部链段运动受到的阻力及表面磨损,优于双端十八烷基全氟聚醚酰胺(损耗因子为0.75)。

Fluorinated silica modified nitrile butadiene rubber(NBR)was synthesized from NBR and three types of double-ended silohydroperfluoropolyether-b-polysiloxane(PFPE-b-PSi-H)antifriction agents,which were prepared from perfluoropolyether allyl ether and three kinds of double-ended hydrogen containing silicone oil(PSi-H)and characterized by FTIR and ^(1)HNMR.The wear,friction coefficient,tensile properties,hardness,DMA and TGA of fluorine-modified NBR obtained were then tested and analyzed.The results showed that the addition of PFPE-b-PSi-2,prepared from PSi-H with a mass fraction of Si—H of 0.115%,better improved the performance of modified NBR.Moreover,when the amount of PFPE-b-PSi-2 added was 2.0% of the mass of NBR,the Akron abrasion volume decreased from 0.250 cm^(3) to 0.125 cm^(3),the static friction coefficient decreased from 2.589 to 1.402,the dynamic friction coefficient decreased from 2.176 to 1.209,the tensile strength increased from 21.4 MPa to 24.2 MPa,and the Shore A hardness decreased from 81to 79 degree in comparison to those of unmodified NBR.Meanwhile,the glass transition temperature was increased from 1.7℃ to 5.7℃,the loss factor was increased from 0.73 to 0.78,the TGA at 10% mass loss was increased by 65℃,and the residual carbon rate was increased by 9.47%.All the data suggested that the friction reducer added decreased the resistance to internal segment movement and surface wear of NBR,which was superior to double-ended octadecyl perfluoropolyether amide(loss factor is 0.75).