中文名稱：3,6-二甲基-1,4-二氧雜環己烷-2,5-二酮、DL-丙交酯、内消旋乳酸

英文名稱：3,6-Dimethyl-1,4-dioxane-2,5-dione、(+/-)-3,6-Dimethyl-1,4-dioxane-2,5-dione、DL-Lactide

3,6-二甲基-1,4-二氧雜環己烷-2,5-二酮（或 rac-丙交酯），是D和L-丙交酯50:50的外消旋混合物。rac-丙交酯是一種(zhǒng)衍生自乳酸的内酯，因其源自豐富的可再生資源而引起(qǐ)了學(xué)術界和商業應用的極大興趣。通過(guò)使用各種(zhǒng)金屬或有機催化劑，rac-丙交酯可以通過(guò)開(kāi)環聚合進(jìn)行聚合，從而得到聚（D，L-丙交酯）。雖然所得聚合物通常是無定形的，但立體定向(xiàng)催化劑的使用可生成(chéng)異順性PLA，其表現出一定程度的結晶度。

3,6-dimethyl-1,4-dioxane-2,5-dione (or RAC lactide) is a racemic mixture of D and L-lactide in the ratio of 50:50. RAC lactide is a lactone derived from lactic acid. It has attracted great interest in academic and commercial applications because of its rich renewable resources. By using various metal or organic catalysts, RAC lactide can be polymerized by ring opening polymerization to obtain poly (D, L-lactide). Although the resulting polymers are usually amorphous, the use of stereotactic catalysts can produce heterocis PLA, which shows a certain degree of crystallinity.