91视频H污污

Natural rubber O-Rings is a latex from rubber trees known chemically as polyisoprene. Polyisoprene can also be copolymerized by monomer isoprene. Natural rubber has many excellent physical properties, including high elasticity, high strength and good wear resistance. Similar to SBR, due to the existence of double bonds in the polymeric backbone chain, it has poor tolerance to hydrocarbon oil, and is not suitable for UV resistance, oxygen, ozone. However, its weather resistance can be improved by additives.

Natural rubber o-rings  Detailed information

Usually what we call the natural rubber, it is to point to from southeast Asia, rubber trees such as Brazil, natural rubber latex, after solidification, drying and other processing operations and elastic solid material, made of natural rubber (NR) is a kind of cis - 1, 4 - polyisoprene as the main component of natural high molecular compound, its content is 91% ~ 94% rubber hydrocarbon (cis - 1, 4-polyisoprene), and the rest is non-rubber substances such as protein, fatty acids, ash and sugars.

Physical properties of natural rubber.
Natural rubber has high elasticity at room temperature, slightly plastic, has very good mechanical strength, small hysteresis loss, low heat generation during multiple deformation, so its flexural resistance is also very good, and because it is non-polar rubber, it has good electrical insulation performance.
Chemical properties of natural rubber.
Because there are unsaturated double bonds, so natural rubber is a chemical reaction ability of strong substances, light, heat, ozone, radiation, flexion deformation and copper, manganese and other metals can promote rubber aging, aging resistance is the fatal weakness of natural rubber, but the natural rubber added with antioxidants, sometimes in the sun for two months still can not see much change, It can still be used after three years in the warehouse.

Dielectric resistance of natural rubber.
Natural rubber has good alkali resistance, but is not resistant to strong acid. Because the natural rubber is non-polar rubber, only able to withstand some polar solvents, and in the non-polar solvent swelling, therefore, its oil resistance and solvent resistance is very poor, in general, hydrocarbons, halogenated hydrocarbons, carbon disulfide, ether, advanced ketones and advanced fatty acids have a dissolution effect on natural rubber, but its solubility is affected by the degree of plastication, However, lower ketones, lower esters and alcohols are non-solvents for natural rubber

The development history of natural rubber:

础辫辫濒颈肠补迟颈辞苍：
Because natural rubber has a series of physical and chemical properties, especially its excellent resilience, insulation, water insulation and plasticity characteristics, and after proper treatment also has oil resistance, acid resistance, alkali resistance, heat resistance, cold resistance, pressure resistance, wear resistance and other valuable properties, so widely used in rubber seals, sealing gaskets, shock-proof gaskets, gaskets, gaskets, gaskets, gaskets, gaskets, gaskets, gaskets, gaskets, gaskets, gaskets, gaskets, etc. Rain shoes used in daily life, surgeon's gloves used in the medical and health industry, blood transfusion tubes, condoms; Various tires used in transportation; Conveyor belts, conveyor belts, acid and alkali resistant gloves for industrial use; Irrigation hose and ammonia water bag used in agriculture; Sounding balloons for weather measurements.

Variety classification:

Natural rubber can be divided into two categories according to its form
1.Solid natural rubber (sheet and pellet)
2.Concentrated latex
Rubber sheet according to the manufacturing process and shape of different, can be divided into smoke sheet , air dry sheet, white wrinkle, brown wrinkle and so on.   Smoke sheet rubber is the most representative variety of natural rubber, has always been a large amount of widely used rubber, smoke sheet rubber is generally classified according to the shape, divided into super grade, one, two, three, four, five and other six levels, less than five is listed as equal outer rubber.
Particle rubber (that is, standard rubber) is graded according to the internationally unified physical and chemical performance and indicators, these physical and chemical properties include impurity content, plastic initial value, plastic retention rate, nitrogen content, volatile matter content, ash content and color index and other seven items, in which the impurity content is the dominant indicator, according to the number of impurities divided into 5L, 5, 10, 20 and 50 a total of five levels.