聚酯Polyester

芳香族聚酯（PET、PBT、聚碳酸酯属碳酸酯）刚性好、耐热，用作纤维和工程塑料；脂肪族聚酯（聚乳酸 PLA、聚己内酯 PCL、聚羟基脂肪酸酯 PHA）柔性较好且可生物降解。全芳香族液晶聚酯（如 Vectra）熔体中呈液晶有序，强度和耐热极高。不饱和聚酯含马来酸酐单元，溶于苯乙烯后可自由基交联固化，与玻璃纤维制成玻璃钢。

Aromatic polyesters such as PET and PBT (polycarbonate is a carbonate ester) are stiff and heat-resistant, used as fibres and engineering plastics; aliphatic polyesters such as polylactic acid (PLA), polycaprolactone (PCL) and polyhydroxyalkanoates (PHA) are more flexible and biodegradable. Wholly aromatic liquid-crystal polyesters such as Vectra are ordered in the melt and extremely strong and heat-resistant. Unsaturated polyesters contain maleic anhydride units; dissolved in styrene they cure by radical crosslinking and, with glass fibre, make fibreglass.

1901 年斯米斯用甘油与邻苯二甲酸酐制得醇酸树脂，后用于涂料。1929–1930 年卡罗瑟斯研究脂肪族聚酯，但其熔点太低而转向聚酰胺。1941 年温菲尔德和迪克森改用芳香族对苯二甲酸，得到高熔点的 PET。1940 年代不饱和聚酯玻璃钢问世，用于雷达罩和船体。

In 1901 Smith made alkyd resins from glycerol and phthalic anhydride, later used in paints. In 1929–30 Carothers studied aliphatic polyesters but turned to polyamides because their melting points were too low. In 1941 Whinfield and Dickson switched to aromatic terephthalic acid and obtained high-melting PET. Unsaturated polyester fibreglass appeared in the 1940s for radomes and boat hulls.

聚酯纤维（涤纶）是产量最大的合成纤维，占全球纤维产量一半以上。聚酯还用于瓶子、薄膜（录像带、太阳能背板）、电子连接器（PBT）、粉末涂料、玻璃钢船艇与卫浴、可吸收缝线（聚乙醇酸）和 3D 打印线材（PLA）。

Polyester fibre is the most produced synthetic fibre, over half of all fibre output worldwide. Polyesters are also used for bottles, films (video tape, solar backsheets), electrical connectors (PBT), powder coatings, fibreglass boats and bathroom fittings, absorbable sutures (polyglycolic acid) and 3D-printing filament (PLA).