| 摘要 |
<p>A block copolymer is disclosed which includes an ethylene-propylene copolymer segment (A) and a tetrahydrofuran segment (B). The weight ratio of (A) to (B) is 5/95 to 9515, and the block copolymer has a number-average molecular weight of about 1,000 to about 1,000,000.</p> |
