Interpretation of the mechanism of 3,3′-dichloro-4,4′-diamino diphenylmethane synthesis over HY zeolites

Catalytic activities of zeolites HY, Hβ and HZSM-5 in the heterogeneous synthesis of 3,3′-dichloro-4,4′-diaminodiphenyl methane (MOCA) from o-chloroaniline and formaldehyde were pre-screened in an autoclave, and HY demonstrated better performance than others. Kinetic behaviors of MOCA synthesis over HY(11) were further investigated in a fixed bed continuous flow reactor, and under the conditions of the catalyst bed volume = 20 mL (8.14 g), n(o-chloroaniline) : n(HCHO) = 4 : 1, LHSV = 3.5 h⁻¹, 0.5 MPa and 443 K, HCHO conversion and MOCA selectivity steadily fluctuated at high levels of 90–92% and 75–77% during 16 h, respectively. Catalysts were characterized by BET, NH₃-TPD and XRD, products analyzed by HPLC, and reaction intermediates identified by LC/MS and ¹H NMR. The mechanism of MOCA synthesis has been interpreted in detail, which also suggested that deposition of basic intermediates on active sites and accumulation of polymeric by-products in pore channels of the catalyst could cause significant decay of HY(11) activity and selectivity under severe conditions. Supplementary tests on catalyst regeneration confirmed that the acidity and surface area of spent HY(11) could be well recovered after burning off the deposited by-products.

Catalytic activities of zeolites HY, Hβ and HZSM-5 in the heterogeneous synthesis of 3,3′-dichloro-4,4′-diaminodiphenyl methane (MOCA) from o-chloroaniline and formaldehyde were pre-screened in an autoclave, and HY demonstrated better performance than others.     

健康教育在糖尿病周围神经血管病变中的应用观察

目的探讨健康教育在糖尿病周围神经血管病变中的应用效果。方法选取2011-09—2014-09我科收治的112例糖尿病周围神经血管病变患者为研究对象,按照随机分配原则将其分为对照组、研究组,每组56例。对照组实施一般护理方案,研究组实施一般护理+健康教育方案。观察对比2组血糖控制情况、心理状况评分及生化指标、疾病认知掌握情况。结果研究组血糖控制情况优于对照组,差异有统计学意义(P0.05)。研究组SAS评分、SDS评分均高于对照组,研究组心理状态优于对照组,差异有统计学意义(P0.05)。结论将健康教育用于糖尿病周围神经血管病变患者的临床护理中,可显著改善患者心理状态,提升患者疾病认知度,对患者血糖控制、疾病恢复十分有益,值得推广应用。