By 1964 synthetic rubber made up 75% of the market.

到1964年的时候，合成橡胶占美国市场的75%。

Chemists discovered how to make synthetic rubber.

化学家发现了制造合成橡胶的方法。

This is used to make the synthetic rubber in car tyres.

它常用以制造汽车轮胎的合成橡胶。

Isoprene needs to be extremely pure to make synthetic rubber.

而异戊二烯必须极其纯净才能生产出合成橡胶。

Synthetic rubber latex is made by emulsion polymerization.

合成橡胶胶乳由乳液聚合制成。