聚酚 是甚麼?

2007-02-13 9:57 pm
聚酚 是甚麼?
更新1:

聚酚類 是消除破壞人體細胞的化學物質的抗氧化劑 它的化學成份和特性是甚麼?

回答 (2)

2007-02-13 10:28 pm
✔ 最佳答案
烃化聚酚类防老剂是新开发的耐抽提、抗老化性能好,且永不变色,是目前浅色橡胶制品首选的防老剂品种,另外也是天然和聚氯丁二烯橡胶最佳防老剂。烃化聚酚化学名称为:对甲酚和双环戊二烯丁基化反应产物,烃化聚酚合成主要分为两步,先由对甲酚和双环戊二烯进行缩聚,然后在异丁烯存在下进行烃基化。
具体工艺过程为:130g对甲酚、9g催化剂,一起被加热到100℃ ,然后将132g双环戊二烯于3 ,5h内慢慢滴加,让其进行缩聚反应,反应后过量的对甲酚在真空4mmHg、150℃下被蒸出,再将上述缩聚物料236g溶于相等量的甲苯中,添加进硫酸4g,加热至8O℃后于1小时45分钟内通入异丁烯168g,进行烃化反应,反应后硫酸用碳酸钠水溶液进行中和,再于真空30mmHg、175℃下蒸发出挥发份及未反应物料,最后过滤出催化剂残渣,得到烃化聚酚产品313。
2007-02-16 11:49 pm
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用熔融共混法制備了尼龍66/聚酚氧共混物,對其力學性能、結晶與熔融行爲及組分間相容性進行了表徵。共混物只有一個玻璃化轉變溫度,且符合線性加和規則;觀察不到兩相形態,表明兩組分相容。隨聚酚氧含量增加,尼龍66的冷結晶溫度昇高、熔融溫度和熔體結晶溫度降低,結晶和熔融溫度範圍變寬,熔融熱和結晶熱降低。共混物的屈服強度、斷裂強度和斷裂伸長率均呈正協同效應,並在聚酚氧含量 30%~40%(均爲質量分數)呈極大值。隨聚酚氧含量的增加,斷裂強度與屈服強度的差值變小,當聚酚氧含量達到80%時,二者已無明顯差別。

http://www.ceps.com.tw/ec/ecjnlarticleView.aspx?jnliid=1279&issueiid=9041&atliid=108840

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The blends of polyethersulfone and phenoxy (聚酚) were prepared by melt mixing in a Brabender-like apparatus. The specimens for measurements were made by compression molding and then were water-quenched at room temperature under pressure. The tensile strength, tensile modulus, elongation at break and yield, density, thermal analysis, and dynamic mechanical properties were each measured. The dependence of tensile strength, tensile modulus, elongation at break and yield, and density on composition was obtained. The relationship between tensile modulus and elongation at break and yield and speed of the crosshead at different weight ratios of the blends is shown. The effects of composition and miscibility on the mechanical properties are discussed.

http://cat.inist.fr/?aModele=afficheN&cpsidt=2997370

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