Natural rubber is a naturally occurring nano-composite, which possesses a complicated hierarchal structure. A primary structure of natural rubber is ω'-(trans)₂-(cis)_n-α' : that is, modified dimethylallyl group, 2 trans-1,4-isoprene units, about 5,000 cis-1,4-isoprene units and modified prenol group, aligned in this order. The ω'-terminal unit and α'-terminal unit may be attracted to proteins and phospholipids through strong attractive forces, which are comparable to attractive forces in chemical bonds; so that, three dimensional network structure of natural rubber is formed with the proteins and phospholipids to generate gel fractions. The proteins and phospholipids are incorporated into the nanomatrix structure, in which natural rubber particles with an average diameter of 1 μm are dispersed in matrix of non-rubber components such as the proteins and phospholipids. The hierarchal structure realizes not only entropy elasticity but also energy elasticity. It creates new science and technology of rubber and opens new criteria of molecular and materials designs.

Natural rubber (NR) derived from latex produced by Hevea brasiliensis (para rubber tree) is an important raw material consumed annually of 12.6 million tons, about of which 70% is used in the tire industry. NR has specific excellent characteristics and is also a material attracting attention as natural resource derived from plants. Since the demand for tires will increase with the development of motorization in emerging countries, stable supply of natural rubber is an important issue for the tire industry. In order to achieve both tropical environmental conservation and increased production, it is necessary to increase productivity per unit area in cultivated areas. Development of varieties that are excellent in productivity has so far been dependent on selective breeding technology by crossing requiring a long time, but recently, research based on a new approach applying biotechnology is advancing.

Despite the considerable time that have passed since the invention of synthetic rubber, natural rubber continues to be widely used across various industries thanks to its superior qualities of carbon neutrality and sustainability. Extensive effort has been put into its research and development with the aim of producing higher performance natural rubber.

This article reviews the historical background and production processes before detailing the physical properties and applications of both epoxidized and highly purified natural rubbers.

Production of natural rubber is a kind of bio-industry which needs large scale plantation, a huge sum of money and assets/The more latex be produced from natural rubber plants with high polyisoprene content, the more advancement of production are needed to improve the cost-performance financially. Then, in order to improve the production of plantation, the process of selection breeding and cultivation has been continuing for over 150 years. Since the natural rubber industry depends on the bioresource of plants, the improvement of production will be an industrial theme forever.

Natural rubber tree has a special organ named lactiferous cell which synthesizes and accumulates hydrophobic compound.This report gained a bio imagine of lactiferous cell of two kinds of natural rubber plants by using articulate lactiferous cell localized in Para rubber trees (Hevea brasiliensis Muell. Arg.) of cis-polyisoprene and phloem localized as crystallized polymer in Hardy rubber trees (Eucommia ulmoides Oliver) of trans-polyisoprene. From this result, we introduce the sink and source relationship needed to improve the natural rubber plants production and research the morphological characters of lactiferous cell which stores polyisoprene, a kind of unproductive compound to plants.

This review paper emphasizes the importance of biodiversity and biosecurity of natural rubbers. Characteristics of guayule natural rubber and dandelion natural rubber are described by comparison with Hevea natural rubber. Espe cially, their unique strain-induced crystallization behaviors and mechanical properties are summarized, which suggest that these natural rubbers can be alternative natural rubbers for Hevea natural rubber. The technique of the collection for these natural rubbers is necessary to be developed in order to efficiently get their solid natural rubbers and natural rubber latexes in a high quality.