摘要
考察了用木质素树脂作填充剂制备的NBR-26/木质素树脂硫化胶的硫化特性、力学性能及结构形态。结果表明,随着木质素树脂用量(50～150质量份)的增加,达到正硫化时对硫化略有延迟作用,但硫化胶仍具有优异的耐热、耐热油老化性能及良好的力学性能。适当控制NBR-26与木质素树脂的共混比可降低基础胶的T_g值,有助于解决NBR-26制品的耐低温性。通过扫描电镜、差示扫描量热及动态粘弹谱表征,NBR-26与木质素树脂之间可达分子级混合,且两组分间存在协同效应。
The lignin -resin ,which is made from the reaction process in which the lignin recovered from the waste liquor of sulfates wood pulping process is treated with formaldehyde , used as reinforcing filler for rubber has been investigated . The excellent results obtained after a special procedure are satisfying .The lignin - resin can be filled in rubber with an appreciable loading amount . The loading amount is between 50 - 150 phr ,even 200 phr ,and the vulcanizate still has excellent mechanical properties heat -oil agjng resistance and heat-oxygen aging resistance , and good curing characteristics.Figure 1 shows the optimum cure time T90, only becomes a little longer with the increase in the loadingamount of lignin - resin . Table 1 shows the mechanical properties of vulcanizate in different NBR-26/ iignin-resin ratios .With the increase in lignin-resin ratio ,there is a considerable increase modulus at 100% .This is because the condensation reaction of hydroxymethyls in lignin-resin at high temperature results in a loose network structure and phenolic hydroxy in lignin -resin can react to NBR-26 ,these two reactions form a dual network structure interlaced with each other ,and play the roles of increasing modulus and keeping high tensile strenth .This effect is superior to other inorganic fillers .Table 2 illustrates the excellent aging resistance of lignin-resin to NBR -26. This is because the essential unit of lignin is guaiacol structure,after reacting to formaldehyde,the products are similar to a sort of hindered phenol with steric hinderance in 2 and 6 position . In phenolic antioxidant, the largerthe adjacent substituent branch , the better the antioxygenation is .In Figure 2 ,the DSC curves show the crosslinkage between lignin-resin and NBR-26. Formation of these crosslinking spots results in a structure in which the stiff chain segments of lignin-resin support the soft butadiene segments of NBR- 26 and make the motion of segments easy , so the Tg of NBR-26 moves to lower temperature . If the loading amount of lignin-resin is too high (150 phr ), the stiff segments will interfere with the motion of the soft segments ,Tg will move to high temperature ( - 15.8°C ).The dynamic viscoelasticity spectra indicate that when the NBR-26/lignin-resin ratios are 100/100 and 100/150 respectively , there is only a loss tangent peak for the two ratios .The SEM photograph shows the vulcanizate is similar to a graft copolymer .After treated with formaldehyde , the lignin recovered from the waste liquor of sulfates wood pulping process becomes lignin - formaldehyde resin and can be loaded in NBR -26 with a large amount , the vulcanizate still have excellent oil resistance , aging resistance and comprehensive mechanical properties .
出处
《合成橡胶工业》
CAS
CSCD
北大核心
1992年第1期12-15,共4页
China Synthetic Rubber Industry
关键词
木质素
硫化胶
协同效应
丁腈橡胶
butadiene-acrylonitrile copdymer
lignin
vulcanizate
relation between structure and properties
synergistic effect
