木粉纳米微晶纤维素补强NR/SBR/BR并用胶的研究

Investigation into Reinforcement of NR/SBR/BR Blends with Wood Cellulose Nanocrystals

利用酸水解木粉制备棒状纳米微晶纤维素(WNC),与天然胶乳(NR)共凝沉制备NR/WNC混合物,将其与丁苯胶(SBR)、顺丁胶(BR)、炭黑(CB)混炼制备WNC/CB/NR/SBR/BR复合材料,研究了WNC部分替代CB对NR/SBR/BR并用胶性能的影响.研究表明:与45 phr CB补强并用胶相比,添加WNC的复合材料的Payne效应显著降低,加工性能得到明显改善,力学性能基本保持,压缩生热下降了18.4%,压缩疲劳变形总体都小于5%;添加5~10 phr WNC的复合材料抗屈挠龟裂性得到保持,WNC为5 phr时复合材料的耐磨耗性得到保持;随着WNC替代CB量的增加,复合材料0℃时的损耗因子tanδ先增后减,60℃的tanδ逐渐下降;质量损失5%时的温度逐渐下降,最大质量损失速率温度变化不大;WNC的加入有利于保持复合材料的老化性能.SEM结果表明,少量的WNC在橡胶基体中分散良好,与基体界面结合紧密.

Clubbed wood cellulose nanocrystals （ WNC ） were prepared via the acid hydrolysis of wood powders and were co-coagulated with natural rubber （NR） latex to form a NR/WNC mixture. Then, the mixture was blended with butadiene-styrene rubber （SBR） , butadiene rubber （BR） and carbon black （CB） to obtain WNC/CB/NR/ SBR/BR composites, and the influence of the partial replacement of CB with WNC on the properties of NR/SBR/ BR blends was investigated. The results show that （1） as compared with the blends reinforced by 45 phr CB, the Payne effect of the composites with WNC weakens apparently, the processability improves obviously, the mechani-cal properties maintain well, the heat build-up decreases by 18. 4% , and the permanent set due to compression fa-tigue is generally lower than 5% ; （2） the resistance to flex cracking of the composites filled with 5 -1 0 phr WNC keeps constant, and the abrasion resistance of the composites filled with 5phr WNC keeps consistent; （3） with the increase of WNC dosage, the loss tangent （tan δ）value o f the composites at 0℃ first increases and then decrea-ses ,while the one at 60℃ gradually decreases; （4） the temperature corresponding to 5% mass loss decreases, while that corresponding to the maximum mass loss rate changes slightly ; and （ 5 ） the ad dition o f WNC helps to maintain the aging performance of the composites. Moreover, SEM results demonstrate that the added WNC with a small quantity displays good homogeneity and strong interfacial interaction with the rubber matrix.