Natural rubber (NR) contains cis-1,4-polyisoprene as well as a small quantity of non-rubber components, affecting the physical properties of NR, especially the storage hardening via gel formation. The free and/or linked non-rubber components were removed from NR by various treatments. The origin of gel formation in NR mainly resulted from proteins, which could be removed by enzymatic deproteinisation, surfactant washing or saponification treatment, and partly from phospholipids linked to NR molecule via H-bonding, which were decomposed by saponification or polar solvent treatment. The effect of the non-rubber components in NR on storage hardening was investigated by an accelerated storage hardening test (ASHT). The crude NR (CNR) containing proteins and lipids clearly showed the increase of gel content, suggesting the formation of crosslink structure during storage, resulting in the high plasticity number and Mooney viscosity after the ASHT. The gel content in protein-free NR did not change significantly only in washed NR (WSNR), but increased in the enzymatic deproteinised NR (DPNR). This resulted from the presence of residual proteins, such as oligopeptides. Interestingly, the gel content also reduced in the acetone extracted CNR (AE-CNR) and there was no significant effect on the storage hardening after ASHT, like WSNR. These were supposed to be due to the interaction or the participation of proteins and free fatty acids in the branching formation. Although the saponification could be decomposed branching at both terminal ends of the NR molecule, the protein and lipid residues occluded in the saponified NR (SPNR) affected the storage hardening. However, the flocculant remaining in the SPNR coagulated with acid and flocculant (AF-SPNR) would obstruct both gel formation and storage hardening.

天然橡胶（NR）含有顺式-1,4-聚异戊二烯以及少量非橡胶成分，会影响NR的物理性能，尤其是通过凝胶形成而引起的存储硬化。通过各种处理从NR中除去游离的和/或连接的非橡胶组分。天然橡胶中凝胶形成的起源主要是通过蛋白质的去除，这些蛋白质可以通过酶促脱蛋白，表面活性剂洗涤或皂化处理去除，部分是通过H键与NR分子连接的磷脂通过皂化或极性溶剂处理而分解。通过加速储存硬化试验（ASHT）研究了NR中非橡胶组分对储存硬化的影响。含有蛋白质和脂质的粗NR（CNR）清楚地表明了凝胶含量的增加，表明在储存过程中形成了交联结构，导致ASHT后的高可塑性值和门尼粘度。不含蛋白质的NR中的凝胶含量不仅在洗涤的NR（WSNR）中没有显着变化，而在酶促去蛋白的NR（DPNR）中增加。这是由于残留蛋白（例如寡肽）的存在所致。有趣的是，丙酮萃取的CNR（AE-CNR）中的凝胶含量也降低了，并且对ASHT后的存储硬化没有明显影响，如WSNR。推测这是由于蛋白质和游离脂肪酸在分支结构中的相互作用或参与。尽管皂化作用可在NR分子的两个末端分解为分支，但皂化NR（SPNR）中的蛋白质和脂质残基会影响存储硬化。然而，