Enormous challenges have been encountered in the degradation and recycling of unsaturated polyester resin (UPR) in water, primarily due to its water resistance. Herein, a novel, efficient and green catalytic system of methanesulfonic acid (MSA)/sodium laurylsulfonate (SLS) was proposed to aqueously degrade UPR under mild conditions (200°C). This method is considerably milder compared to other reported works based on aqueous hydrolysis (230°C-380°C). What's more, amphiphilic SLS as a phase transfer reagent enhanced the concentration of catalyst at the HO-UPR interface, which facilitated the mass transfer between organic motifs with inorganic reagents and thus accelerated the reaction. The NMR and FT-IR characterizations indicated the ester bonds were cleaved via hydrolysis with HO catalyzed by MSA, and high value-added products, i.e., copolymer of styrene and maleic anhydride (SMA) and phthalic acid (PA), were reclaimed by a simple separation process, with the yield of 86.77% and 84.37%, respectively. Furthermore, a viable mechanism for degradation was proposed through the degradation performance of the model compounds. This study provides a practical approach for the chemical degradation and conversion of other resins containing ester bonds.

中文翻译：

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两亲性分子可有效降解不饱和聚酯树脂的水相

不饱和聚酯树脂（UPR）在水中的降解和回收遇到了巨大的挑战，这主要是由于其耐水性。在此，提出了一种新型、高效、绿色的甲磺酸（MSA）/十二烷基磺酸钠（SLS）催化体系，可在温和条件（200°C）下水降解UPR。与其他报道的基于水水解（230°C-380°C）的方法相比，该方法要温和得多。此外，两亲性SLS作为相转移试剂提高了HO-UPR界面催化剂的浓度，促进了有机基序与无机试剂之间的传质，从而加速了反应。 NMR和FT-IR表征表明，酯键通过MSA催化的H2O水解而断裂，并回收了高附加值产品，即苯乙烯与马来酸酐（SMA）和邻苯二甲酸（PA）的共聚物。分离过程简单，收率分别为86.77%和84.37%。此外，通过模型化合物的降解性能提出了可行的降解机制。该研究为其他含酯键树脂的化学降解和转化提供了实用的方法。