木质素磺酸盐的分散研磨性能和改性研究

Dispersing and Grinding Performance of Lignosulfonates and their Modification via Crosslinking Reactions

为提升低品质木质素磺酸盐的分散研磨性能,以高品质的Reax 85A为基础性研究的对象,通过不同截留分子量的超滤膜对它进行分子量分级,获得了三个不同特性黏度([η])的木质素磺酸盐组分。将它们作为分散剂对C.I.分散蓝354的原染料进行研磨以考察其分散研磨效率。结果表明,木质素磺酸盐的分散研磨性能与其特性黏度大小正相关。为验证这一结论,在苯酚和甲醛的存在下,对特性黏度较小的木质素磺酸盐进行了分子量嫁接的改性反应,并考察了各改性产物作为分散剂在相同实验条件下对同一染料的分散研磨效率。结果表明,改性产物的特性黏度随苯酚和甲醛投料质量比的增加而增大,但是苯酚和甲醛的投料质量比不宜过大,否则会有酚醛缩合物生成;特性黏度较大的改性产物其分散研磨性能也较好,组分R-00([η]=2.25)与Vyborg([η]=3.74)经嫁接反应后获得的改性产物([η]=4.28)使同一染料分散体的扩散度达到5级只需要16 h,其分散研磨效率高于Reax 85A。

In order to improve dispersing performance of low quality lignosulfonates, high qualitylignosulfonate （Reax 85A） was used to prepare three different fractions of Reax 85A with different intrinsicviscosities （[η]） by membrane ultrafiltration. Their dispersing efficiency for C.I. Disperse Blue 354 wasevaluated. The results indicate that their dispersing efficiency is positively associated with their intrinsicviscosity. Crosslinking reactions were performed between lignosulfonates with low intrinsic viscosities in thepresence of phenol and formaldehyde, and the dispersing efficiency of the products was evaluated bysand-milling under the same conditions. The results illustrate that when the mass ratio of phenol andformaldehyde increases, the intrinsic viscosity of the crosslinking product also increases. However, the massratio cannot be overhigh which results in the condensation of phenol and aldehyde. Products with higherintrinsic viscosity possess higher dispersing efficiency. The product （[η] = 4.28） obtained from crosslinkingbetween R-00 （[η]= 2.25） and Vyborg （[η] = 3.74） shows good dispersion efficiency for C.I. Disperse Blue 354,and it takes only 16 h to make the dye diffusion to reach degree 5, which is better than Reax 85A.