The Improvement Of Synthesis Process Of ε-caprol Actone-modified Dipentaerythritol Hexaacrylate

Polyol acrylate ester is a kind of important fine chemical products which has awide range of application in many areas such as lubricants, adhesives, plasticizer,surface active agent, as well as in the ink, resins and resin modifying agent,crosslinking agent, coating, and other fields. With the development ofpentaerythritol in our country, the synthesis and applied research of dipentaerythritolacrylate has been increasing, but the study on ε-caprolactone-modifieddipentaerythritol hexaacrylate is relatively less. Now ε-caprolactone-modifieddipentaerythritol hexaacrylate can meet the basic requirements, however, the largeviscosity, high molecular weight, deep color lead to its bapplication has beenblocked in some aspects. Therefore, in this paper we make a systematic study for theimprovement of synthesis process of ε-caprolactone-modified dipentaerythritolhexaacrylate.First, at a certain molar ratio of alcohol and acid, ε-caprolactone and dosage ofcatalyst, we investigate the effects of disaggregators dry magnesium chloride dosage,The add temperature and time of ε-caprolactone by single factor experients, then weobtain optimum reaction conditions: The molar ratio of dipentaerythritol andε-caprolactone was1.0:1.0; The molar ratio of dipentaerythritol and acrylic acid was1.0:6.2; The dosage of p-toluene sulfonic acid catalyst was4.0g; The dosage ofε-caprolactone was8.82g; The dosage of toluene was90mL; The dosage ofanhydrous magnesium chloride was2.5%of ε-caprolactone; The add temperatureand time of ε-caprolactone was110℃,1h. When the number average molecularweight was2629g·mol-1and weight average molecular was5740g·mol-1, theproduct shows good color.Second, determining the ε-caprolactone, dipentaerythritol and catalyst, weinvestigate the dosage of anhydrous magnesium chloride, the molar ratio of acrylicacid and ε-caprolactone, the add time and temperature of ε-caprolactone under solvent-free body, then we obtain optimum reaction conditions: The molar ratio ofdipentaerythritol and ε-caprolactone was1.0:1.0; The molar ratio of ε-caprolactoneand acrylic acid was1.0:2.0; The dosage of p-toluene sulfonic acid catalyst was4.0g; The dosage of ε-caprolactone was8.82g; The dosage of Anhydrous magnesiumchloride was2.0%of ε-caprolactone; The add temperature and time ofε-caprolactone was110℃,1h. When the number average molecular weight was1946g·mol-1and weight average molecular was5290g·mol-1, the product has goodcolor and high transparency.In addition, we further investigate the preparation of6-hydroxy caproic acidusing for modifing dipentaerythritol hexaacrylate.6-hydroxy caproic acid isobtained by hydrolysisingε-caprolactone with neutralization, extraction, washing,enrichment. Then it was confirmed by IR and1H NMR. Making the final productwe determine the dosage of6-hydroxy caproic acid, the influence of time andtemperature, obtaining optimum reaction conditions: The molar ratio of6-hydroxycaproic acid and acrylic acid was1.0:1.0; The molar ratio of6-hydroxy caproic acidand dipentaerythritol was1.0:1.0; The dosage of p-toluene sulfonic acid catalyst was4.0g; The add temperature and time of6-hydroxy caproic acid was110℃,2h. Theviscosity of product with good colour and lustre was16.073Pa·s.The performance of three products was good such as on the mixed viscosity,chemical resistance. The gloss and transparency of products was similar, and thecolor was better than original. But with6-hydroxy caproic acid to improve thesynthetic process, the viscosity of product was low. By using compressed air toreprocess the products, the solvent content conforming to the requirements of theindustry is47PPM.