Study on the Preparation and Life of Polymercaptan Curing Agent

环氧固化剂种类繁多，但大多数固化剂存在固化温度高或固化速度慢等缺点，而聚硫醇在叔胺的促进下显示出优异的低温快速固化性能。目前，聚醚型聚硫醇全靠进口，为填补国内这方面空白，本文对聚醚型聚硫醇的实验制备做了大量研究。另外，研究了促进剂对不同类型聚硫醇活性的影响及几种促进剂对聚硫醇/环氧树脂固化促进效果的影响，具体工作内容如下： 本文以结晶四氯化锡为催化剂，环氧氯丙烷（ECH）、聚醚多元醇（GE303）为原料合成中间体PCE，并用硫氢化钠与PCE进行亲核反应合成了聚醚型聚硫醇PSH。对合成的中间体PCE及聚硫醇PSH进行了FT-IR和1H-NMR表征，证明环氧氯丙烷与羟基反应完全，且第二步的亲核取...There is a wide range of epoxy-curing agents. However, most of them have some common shortcomings, for instance, high curing temperature and long curing time. What pleases us is that polymercaptan shows excellent curing performance with the help of tertiaryamine. Nowadays, the domestic polyether polymercaptan relies heavily on imports. To fill in the blank this area, we did plenty of experiments o...学位：理学硕士院系专业：材料学院_高分子化学与物理学号：2072011115007

Studies on Curing Shrinkage of Liquid Optical Clear Adhesive

紫外光固化的液态光学胶固化过程中出现的体积收缩现象,严重影响其黏接强度和产品外观.系统研究了液态光学胶预聚物的种类、活性稀释剂的种类和用量、光引发剂的用量、光固化的类型等诸多因素对固化收缩率的影响.研究发现,以聚乙二醇二丙烯酸酯作为预聚物可明显降低固化收缩率.当添加的活性稀释剂官能度相同时,胶黏剂的固化收缩率随活性稀释剂相对分子质量的增加而减小;当活性稀释剂相对分子质量相近时,官能度增加,固化收缩率随之增大.而光引发剂的用量则对固化收缩率无明显影响.阳离子型胶黏剂的固化收缩率比自由基型的小,但硬度和黏接强度较低;而混杂型的固化收缩率则介于二者之间.The volume shrinkage during UV-curing of liquid optical clear adhesives(LOCA)had a serious effect on the adhesive strength and appearance of the product.In this paper,the effect of different factors,including types of active diluents,amounts of active diluents and photo-initiators,and UV-curing types,on the volume shrinkage for LOCA was systematically investigated.Based on the experiment,polyethylene glycol diacrylate as the prepolymer could significantly reduce the shrinkage.With the same functionality of the added active diluents,the shrinkage decreased when the molecular weights of the active diluents increased.When the molecular weights of active diluents were similar,the shrinkage increased with the increase of the functionality.The amount of photo-initiators had no significant effect on shrinkage.The shrinkage of cationic adhesives was smaller than that of radical adhesives,but the hardness and adhesion strength were relatively lower.The shrinkage of hybrid adhesives was in between in general

Study on Activity Persistance of Polyester Polymercaptan Curing Agent

对比了聚醚型聚硫醇和2种聚酯型聚硫醇的活性寿命的差异.通过红外光谱、1 H-nMr和凝胶时间的测试表征聚硫醇的活性寿命.结果表明,以叔胺为促进剂时,以β-巯基丙酸为原料制备得到的聚酯型聚硫醇P(SH)6和聚醚型聚硫醇P(SH)3固化剂都有良好的活性寿命;而以α-巯基乙酸为原料制备得到的聚酯型聚硫醇P(SH)4固化剂存在活性下降的问题,2个月后完全失活.通过红外光谱、1 H-nMr表征活性下降前后其基团的变化提出了可能导致其活性下降的机理及解决的方法.The lifetime differences of polyether polymercaptans and two kinds of polyester polymercaptans were compared in this paper.The lifetime of polymercaptans curing agents was characterized by FT-IR,1 H-NMR and gelation time.The results revealed that polyester polymercaptans P(SH)6and polyether polymercaptans P(SH)3composed of 3-mercaptopropionic acid showed a long lifetime when using trialkylamine as accelerator,while polyester polymercaptans P(SH)4composed of 2-mercaptopropionic acid showed a decrease in curing activity and deactivated within two months.Possible mechanism of the decrease in curing activity was proposed based on the investigation of group changes during the deactivation by FT-IR and 1 H-NMR

Research on the Treatment of Highly Concentrated Phenolic Wastewater

采用fEnTOn系列方法处理高浓度酚醛废水,考察了各方法对化学需氧量(COd)去除率的影响.首先,确定了fEnTOn-uV氧化中H2O2溶液添加量、fE2+与H2O2摩尔比、PH值、光照时间等因素的较优水平;同时结果表明,将fEnTOn氧化法与超声和紫外光照射联用显著改善了处理效果,COd去除率可以达到90%以上;将絮凝法与fEnTOn-uV联用,聚丙烯酰胺加速絮状物沉淀,COd去除率达到70%左右;用红外和核磁手段表征酚醛废水经fEnTOn-uV氧化后的产物,证明fEnTOn-uV氧化法通过苯环侧链氧化断裂的主要途径进行.Several Fenton-related experiments were used to treat highly concentrated phenolic wastewater.Firstly,the optimal level of each factor in the Fenton-ultraviolet light experiment,such as the amount of H2O2,the mole ratio of Fe2+to H2O2,pH value and UV exposure time,was determined.The treatment effect obviously got improved when Fenton treatment was combined with ultrasonication and ultraviolet light irradiation,in which the removal efficiency of chemical oxygen demand(COD)could reach more than90%.In treating the phenolic wastewater by both flocculation and Fenton-UV,polyacrylamide could accelerate the sedimentary rate of the floccules and the COD removal efficiency was around 70%.Characterization of the flocculate emerging in the Fenton-UV oxidation using FT-IR and 1H-NMR methods proved that oxidation and degradation of the benzene ring′s side chains were the main way of Fenton-UV treatment

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^