Yunyan 774 is a newly bred rubber tree cultivar in Yunnan, the research on its latex composition and properties is of great significance for its popularization and application. The changes of non-rubber components and colloidal properties, molecular weight and distribution of Yunyan 774 concentrated natural latex during storage, as well as the differences of crosslinking density, physical and mechanical properties, aging properties and latex particle size and distribution after 90 days of storage were measured and analyzed. The experimental results showed that the total solid content and ash content of Yunyan 774 remained unchanged after 90 days of storage, and the dry rubber content decreased by 1.1%, which was related to the reaction of some non-adhesive substances to form substances that could not be precipitated by adding acid. The content of volatile matter decreased slightly, but the content of acetone soluble content, water soluble content and nitrogen increased in different degrees. The content of advanced fatty acids of Yunyan 774 increased with the extension of storage time, and the ammonium soap with protective effect was generated, which played a role in improving the mechanical stability in the early stage. The thermal stability decreased gradually, and the viscosity decreased first and then was basically constant. The increase of volatile fatty acid content was not conducive to the preservation of latex. The physical mechanical properties and aging properties of Yunyan 774 latex vulcanized rubber film were better than those of the mixed strain. Compared with the mixed strain, the molecular weight distribution of Yunyan 774 was wider, the molecular weight was slightly lower, and the particle size was not different.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |