林升博　赵艳芳　廖双泉　宾健　廖小雪

摘 要 对比天然橡胶5号胶，采用海藻酸钠作为辅助剂制备颗粒天然橡胶（SK-NR），探讨海藻酸钠用量对SK-NR的凝固过程、力学性能、加工性能和热稳定性的影响。结果表明，颗粒胶是通过浓度梯度作用使凝固剂从外至里渗透凝固；与SCR-5相比，SK-NR的MH增大，T90缩短；随海藻酸钠用量的增加，SK-NR胶料的拉伸强度增大，撕裂强度变化不大，当海藻酸钠质量分数为1.0%时胶料的综合性能较好；RPA分析表明，海藻酸钠的加入会影响混炼胶的内耗；热稳定性分析表明，海藻酸钠在220～280 ℃间会裂解脱水，生成稳定的中间产物，导致SK-NR提前失重。

关键词 天然胶乳；海藻酸钠；颗粒天然橡胶；水化层；性能

中图分类号 TQ332 文献标识码 A

Abstract Sodium alginate was added into natural rubber latex SCR-5 to produce pimpled rubber（SK-NR）， and the dosage on the solidification process， mechanical properties， process ability and thermal stability of SK-NR was studied. The results showed that the solidification process of pimpled rubber particles， under the effect of concentration gradient， occured from the outside to the inside. Compared with SCR-5， the maximum torque of SK-NR increased and cure time was shortened. The tensile strength of SK-NR increased with more sodium alginate used， the tear strength changed little. The mass fraction of 1.0% sodium alginate had a better comprehensive performance. RPA analysis showed that adding sodium alginate could change internal friction of SK-NR， and could speed the process of vulcanization. Thermal stability analysis revealed sodium alginate could pyrolyze to dehydrate between 220-280 ℃ to generate stable intermediate， which leading to SK-NR and YK-NR weightlessness in advance.

Key words Natural rubber latex； Alginate； Natural rubber particles； Hydration shell； Performance

doi 10.3969/j.issn.1000-2561.2015.11.028

天然胶乳主要采集于巴西橡胶树，其成分除了主要的橡胶烃（聚异戊二烯）之外，还有少量的蛋白质，脂肪酸、糖分等非胶组分。目前天然胶乳的凝固方法主要有酸凝固、盐凝固、微生物凝固、微波凝固、真空凝固等[1-2]。这些凝固方法所制得的天然生胶是块状，需要经过压薄脱水、造粒等工序。为了简化工艺、减少设备投资、节约能源，需要寻找新的凝固方式來凝固天然胶乳。将天然胶乳直接凝固成颗粒状，实现天然橡胶颗粒状的制备具有以下优势：简化设备，去除传统工艺中的压片脱水和高能耗的造粒过程；实现计量化，连续化，自动化的生产；凝固剂可以重复使用，减少胶厂生产上排放的污水；延长熟化时间，调节P0，减少生产对天然橡胶P0的不利影响[3]。……