Lesson 6　Polybutadiene
Rubber (BR)

New Words

Notes

[1] This high-cis BR was also found to possess superior abrasion resistance and a great tolerance for high levels of extender oil and carbon black. 高順式聚丁二烯橡膠具有優(yōu)異的耐磨性，另外它還具有油和炭黑的高填充性。

[2] High-cis BR was originally blended with natural rubber simply to improve the latter’s processing properties, but it was found that the BR conferred many of its desirable properties to the blend. 高順式聚丁二烯橡膠最初和天然橡膠共混，可以明顯提高天然橡膠的工藝性能，后來發(fā)現(xiàn)共混順丁橡膠能夠改善膠料很多性能。

[3] By selection of catalyst and control of processing conditions, polybutadienes are now sold with various distributions of each isomer within the polymer chain, and with varying levels of chain linearity, molecular weight and molecular weight distribution. 通過選擇不同的催化劑和控制工藝條件，可以得到不同結構單元、線型結構、分子量及其分布的聚丁二烯大分子。

Exercises

1. Translate the first and second paragraphs of the text into Chinese.

2. Put the following words into English.

聚丁二烯橡膠　　　順丁橡膠　　　耐久性　　　　動態(tài)形變　　　滾動阻力

高抗沖聚苯乙烯　　工藝性能　　　順-1，4-加成

BR Blends

Although BR is a significant elastomer it is most commonly used as a blend with other rubbers. Grades are very much dependent on the architecture of the repeating unit in the polymer chain. BR is traditionally difficult to process on rubber machinery; this difficulty is not apparent when BR is blended with other non-polar elastomers such as NR. BR vulcanizates confer high resilience, therefore low heat buildup, and good abrasion resistance to blends with other rubbers (its resilience is excellent and it has a low temperature flexibility second only to silicone rubber). In view of the above properties its major application area is in tires. Other applications are golf ball centers, modification of polystyrene to make high impact polystyrene and miscellaneous products needing improvements in abrasion, low temperature and resilience.

Words and Expressions