Glycine-β-cyclodextrin-assisted cometabolism of phenanthrene and pyrene by Pseudomonas stutzeri DJP 1 from marine sediment

Cometabolic degradation is currently an effective and extensively way to remove high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs).Unfortunately,due to low bio-accessibility and high biotoxicity,the cometabolic degradation rate of HMW-PAHs is limited.Glycine-β-cyclodextrin(GCD)was obtained through amino modification ofβ-cyclodextrin(BCD)and added to cometabolic system of phenanthrene(PHE)and pyrene(PYR)to assist PYR biodegradation.Results show that the addition of GCD(100 mg/L)effectively improved the removal rate of PYR(20 mg/L)by 42.3%.GCD appeared to increase the bio-accessibility and reduce the biotoxicity of PHE and PYR,and then promoted the growth of Pseudomonas stutzeri DJP1 and stimulated the elevation of dehydrogenase(DHA)and catechol 12 dioxygenase(C12O)activities.The phthalate metabolic pathway was accelerated,which improved the cometabolic degradation.This study provided a new reference for the cometabolic degradation of HMW-PAHs.

Synthesis and Characterization of β-Cyclodextrin Modified Biochar Environmental Remediation Materials

In this paper, biochar (BC) was used as raw material, activated by deionizing aqueous solution, NaCl solution, CA solution and HCl solution respectively. Epichlorohydrin (EPI) was used as crosslinking agent, and β-cyclodextrin (β-CD) was used to modify biochar (BC). The prepared modified biochar materials were labeled with β-CDBC, β-CDBC-Na, β-CDBC-CA and β-CDBC-H, respectively. The infrared spectrum, X-ray diffractometer, scanning electron microscope and specific surface area of the four modified materials were tested. The results showed that the C-O stretching vibration peak at 1020 cm−1 of the modified materials was slightly offset compared with that of biochar. The characteristic absorption peaks of XRD pattern decrease obviously at 2θ = 26.7˚ and 29.5˚. It can be obviously observed on the electron microscope image that the surface is loaded or formed clathrates, and BET data and graphs also show that the specific surface area of the modified biochar is larger. Therefore, β-cyclodextrin successfully modified biochar and formed clathrates on the surface of biochar or was loaded in the pore structure of biochar, especially β-CDBC-CA achieved better modification effect. Because biochar and β-cyclodextrin raw materials are cheap, easy to prepare and green, and less prone to secondary pollution, it has a good advantage in environmental governance.

Synthesis of a Novel UV-curable Prepolymer Polypropyleneglycol Diglycidyl Ether Diacrylate

A novel UV-curable prepolymer polypropyleneglycol diglycidyl ether diacrylate （PPGGEA） was synthesized by utilizing polypropyleneglycol diglycidyl ether （PPGGE） and acrylic acid （AA） as starting materials, N, N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were in the following： the concentration of N, N-dimethylbenzylamine was 0.80 wt% of reactants, the concentration of p-hydroxyanisole was 0.3 wt% of reactants, the reaction temperature was 90-110 ~C, and the molar ratio of PPGGE to AA was 1：2.2. Meanwhile, 1-hydroxycyclohexyl phenyl ketone of a UV-cured initiator was added to the synthesized PPGGEA to prepare a kind of UV-cured coating. The mechanical properties of the UV-cured films were determined, giving 29.99 MPa of tensile strength, 834.27 MPa of the Young＇s modulus and 5.66% of elongation at tear.

Preparation and Characterization of Carboxyl-terminated Poly(butadiene-co-acrylonitrile)-epoxy Resin Prepolymers for Fusion-bonded-epoxy Powder Coating

Liquid carboxyl-terminated poly（butadiene-co-acrylonitrile）（CTBN）-epoxy resin（EP） prepolymers were prepared with different contents of CTBN.The chemical reactions between EP and CTBN were characterized by Fourier ransform infrared（FTIR） spectroscopy and gel permeation chromatography（GPC）.The scanning electron micrograph（SEM） and dynamic mechanical analysis（DMA） of curing films showed phase separation,and the rubber particles were finely dispersed in the epoxy matrix.Mechanical properties analysis of curing films showed that impact strength and elongation at break increased significantly upon the addition of CTBN,indicating good toughness of the modified epoxy resins.Thermogravimetric analysis（TGA） showed that the incorporation of CTBN had little effect on the thermal stability of EP.Fusion-bonded-epoxy（FBE） powder coatings modified with CTBN-EP prepolymers were prepared.The experimental results demonstrate the ability of CTBN-EP prepolymers,toughening technology to dramatically enhance the flexibility and impact resistance of FBE coatings without compromising other key properties such as corrosion protection.

Synthesis of a Novel UV-curable Prepolymer Hexanediol Diglycidyl Ether Diacrylate and Its Cured Film Tensile Property

A novel UV-curable prepolymer hexanediol diglycidyl ether diacrylate （HDGEA） was synthesized by utilizing hexanediol diglycidyl ether （HDGE） and acrylic acid （AA） as starting materials, N, N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor. The optimal synthetic conditions were that the concentration of N, N-dimethylbenzylamine was 0.80 wt% of reactants, the concentration of p-hydroxyanisole was 0.3 wt% of reactants, the reaction temperature was 90-110 ℃, and the molar ratio of HDGE to AA was 1︰2.2. Meanwhile, 1-hydroxycyclohexyl phenyl ketone of a UV-curing initiator was added to the synthesized HDGEA to prepare a kind of UV-curing coating. The mechanical properties of the UV-cured films were determined, giving 31.87 MPa of tensile strength, 871.88 MPa of Young＇s modulus and 6.77% of elongation at tear.

Performance of CTBN(carboxyl-terminated poly (butadiene-co-acrylonitrile))-EP(diglycidyl ether of bisphenol-A (DGEBA)) Prepolymers and CTBN-EP/polyetheramine (PEA) System

CTBN-EP prepolymers were synthesized from CTBN and epoxy resin under the catalysis of HTMAB. FTIR analyses indicate the formation of ester group between the carboxyl group of CTBN and the oxirane group of epoxy resin. The viscosity of modified prepolymer increases with CTBN content increasing, but the epoxy value of the prepolymer decreases greatly. DSC analyses verify that CTBN affects the curing process of CTBN-EP/PEA system. Mechanical testing presents the improved toughness of CTBN-EP/PEA curings for the decrease of tensile strength, flexural strength and compressive strength, and increase of impact strength and elongation-at-break with the CTBN content increasing. SEM micrographs show the rubber phase with many holes in diameter about 0.5-1.5 μm is formed when CTBN content is lower than 10 phr. However, the pattern of SEM graph shows some stalactite-like strips when CTBN content is higher than 15 phr. Furthermore, the SEM image of 25 phr CTBN sample forms a kind of co-continuous structure.

Preparation and Characterization of Phenolic Prepolymer Impregnated Chinese Fir by Cyclic Increasing-Pressure Method with Green and Efficient

The Chinese fir wood was impregnated using a cyclic increasingpressure method(CIPM)with phenolic prepolymers as the impregnating modifier.Unmodified Chinese fir and progressive increasing-pressure method(PIPM)impregnated Chinese fir were used as reference samples and were compared and analyzed.The product’s chemical structure,internal morphology,crystal structure,and heat resistance were characterized.The transversal and longitudinal sections showed better filling effects,so that it bore greater external loading and reduced the water storage space.CIPM infused more phenolic prepolymer into the Chinese fir.Not only producing more physical filling but also forming more hydrogen bond associations and chemical bond combinations.Compared with PIPM and unmodi-fied Chinese fir,the CIPM impregnated Chinese fir had better mechanical strength and water resistance.The cellulose chains in CIPM impregnated Chinese fir were more closely linked and their crystallinity were clearly improved.Changes in internal morphology and crystal structure explained the reason why the mechanical properties and water resistance of CIPM impregnated Chinese fir were improved significantly.This Chinese fir had lower thermal decomposition rates,higher decomposition residual rates,and smaller combustion flames,which confirmed that it possessed improved heat and fire resistance.

Synthesis of a novel UV-curable prepolymer neopentyl glycol diglycidyl ether diacrylate and its cured film tensile property

A novel UV-curable prepolymer neopentyl glycol diglycidyl ether diacrylate (NPGGEA) was synthesized by using neopentyl glycol diglycidyl ether (NPGGE) and acrylic acid (AA) as starting materials, N, N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were taken as follows: The concentration of N,N-dimethylbenzylamine, 0.80% of reactants; the concentration of p-hydroxyanisole, 0.3% of reactants; the reaction temperature, 90-110 ; the molar ratio of NPGGE to AA, 1:2.2. Meanwhile, 1-hydroxycyclohexyl phenyl ketone of a UV-cured initiator was added to the synthesized NPGGEA to prepare a kind of UV-cured coating. Mechanical properties of the UV-cured films were determined, giving 28.75 MPa of tensile strength, 923.82 MPa of Young’s modulus and 5.51% of elongation at tear.

Preparation of waterborne polyurethane/β-cyclodextrin composite nanosponge by ion condensation method and its application in removing of dyes from wastewater

Currently,polymer nanosponges have received extensive attention.However,developing new synthetic techniques for novel nanosponges remains a challenge.Furthermore,to date,composite nanosponge adsorbents based on waterborne polyurethane(WPU)andβ-cyclodextrin(β-CD)have not been reported.Herein,a novel green method,ion condensation method,was developed in this study for the preparation of polymer nanosponge adsorbents for efficient removal of dyes from wastewater.Based on the principle of charge repulsion between nanoparticles to maintain emulsion stability,waterborne polyurethane/β-cyclodextrin composite nanosponges(WPU-x,y)were prepared by coagulating the emulsions synthesized from 2,2-dimethylolpropionic acid,polypropylene glycol and hexamethylene diisocyanate as raw materials in a mixture of hydrochloric acid and anhydrous ethanol.The structure and appearance of WPU-x,y were characterized by attenuated total reflectance Fourier transform infrared spectroscopy,thermal gravimetric analyzer,scanning electron microscope and mercury intrusion porosimetry.The adsorption capacity of WPU-x,y was tested by parameters such as cross-linking degree,β-CD dosage,contact time,initial dye concentration and p H value.The study found that WPU-4,4.62 had the best adsorption effect on methylene blue(MB),the maximum removal rate was 93.42%,and the maximum adsorption capacity was 136.03 mg·g^(-1).Moreover,the Sips isotherm and pseudo-second-order-model were suitable for MB adsorption.Therefore,this study provides some perspectives for the fabrication of nanosponge adsorbents.

聚氨酯热熔胶用预聚体的合成

以二异氰酸酯和聚醚多元醇为原料,通过定时测定—NCO的含量,确定了合适的预聚反应时间和温度,制备了聚氨酯热熔胶用预聚体。对影响预聚体合成的因素:异氰酸酯的种类、—NCO的含量、水分的含量以及预聚体的贮存稳定性等进行了探讨。结果表明,最佳预聚反应条件为80℃、2 h,—NCO含量控制在9%~10%,物料中水分质量分数低于0.05%,制备的产物性能稳定。

聚氨酯预聚体中异氰酸酯基含量不确定度评价

聚氨酯被广泛应用,预聚体法是聚氨酯重要的制备方法,而异氰酸酯含量是预聚体的重要指标,尚未见到关于异氰酸酯含量不确定度评价的论文。本文根据HG/T 2409-1992测定聚氨酯预聚体中异氰酸酯基含量,按照JJF1059.1-2012对各影响因素进行分析,得到异氰酸酯基含量为(5.93%±0.12%)(k=2,置信水平95%)。通过对不确定度的评定,综合各因素对不确定度的影响,发现测量重复性引入的不确定是异氰酸酯含量测定不确定度的主要来源。

一种甲氧基封端苯基甲基硅树脂预聚体合成工艺的探究

以苯基三氯硅烷、二甲基二氯硅烷、甲醇、水为原料,水解缩合制备甲氧基封端的苯基甲基硅树脂预聚体.探究了水解和加料方式、溶剂、反应时间、温度等对反应过程及产物性能的影响,通过对预聚物组成、结构及性能的表征,确定了制备液体硅树脂预聚体的最优反应条件.

不同PPG/PCL比例对聚氨酯制备及性能的影响

鉴于多元醇种类繁多、性能各异,且在成型过程中,反应物的黏度、反应活性等对聚氨酯成型操作以及制品性能具有重要影响,因此采用预聚体法,以二苯基甲烷二异氰酸酯的混合异构体(MDI-50)、相同分子量的聚丙二醇(PPG)和聚己内酯二醇(PCL),以及3,3′-二氯-4,4′-二苯基甲烷二胺(MOCA)作为原料制备聚氨酯,研究了多元醇PPG与PCL比例对聚氨酯黏度、反应活性等性能的影响。通过旋转黏度计测试不同PPG/PCL比例预聚体的黏度,发现随着PCL含量增加,预聚体的黏度由166 mPa·s逐渐增大至374 mPa·s。经过傅里叶变换红外光谱结构表征,显示聚氨酯制备成功。利用树脂凝胶试验仪测试聚氨酯的树脂反应活性,发现PPG与PCL的不同配比对聚氨酯的反应活性影响不大。此外,通过万能试验机以及热重分析仪测试聚氨酯的力学性能与热稳定性,结果表明,随预聚体中PCL含量的增加,聚氨酯的拉伸强度呈现先升高后降低的趋势,当PPG与PCL质量比为2∶3时,聚氨酯的拉伸强度达到最大,为19.81 MPa,断裂伸长率为332%,热分解温度最高,最终质量损失率最小。

有机硅丙烯酸酯预聚体的合成及其在UV固化丙烯酸酯压敏胶中的应用

利用单端羟基硅油、异佛尔酮二异氰酸酯、丙烯酸羟乙酯制备了含有氨基甲酸酯基的有机硅丙烯酸酯预聚体。以此预聚体作为硬单体,丙烯酸异辛酯为软单体,低生物毒性2,4,6-三甲基苯甲酰基苯基膦酸乙酯(TPO-L)为光引发剂,采用紫外光(UV)固化聚合制备了吸水性、透水气性、耐水性和粘接性能优异的丙烯酸酯压敏胶。通过二正丁胺反滴定法探究了预聚体合成最佳温度、时间、催化剂用量等工艺参数。研究了光照时间、光引发剂种类及用量对压敏胶固化程度的影响,以及预聚体含量对压敏胶粘接性能、吸水性和湿气透过性的影响。研究结果表明:在有机硅丙烯酸酯预聚体合成中,第一步反应温度为40℃,第二步反应温度为50℃,反应时间都为60 min,催化剂最佳用量为0.10%(质量分数);在改性压敏胶制备中,光照120 s,光引发剂TPO-L用量为3%(质量分数),预聚体含量为20%时制备的压敏胶光固化程度较高,初粘力为21号球,180°剥离强度为5.7 N/(25 mm),持粘力超过360 h,对非极性表面PP板180°剥离强度为3.2 N/(25 mm);改性后的压敏胶吸水性、湿气透过性良好。

预聚体对无溶剂聚氨酯胶黏剂耐蒸煮性能的影响

本文合成了系列聚氨酯预聚体,将其用于制备双组分无溶剂聚氨酯胶黏剂,并利用红外光谱和核磁共振波谱证明预聚体和胶黏剂的结构。通过控制变量法研究了聚氨酯预聚体的异氰酸酯基质量分数(ω_(NCO))、多元醇分子量、R值(胶黏剂中-OH和-NCO基团的摩尔比)对胶黏剂黏度和耐蒸煮性能的影响。结果表明,在ω_(NCO)为17%时,预聚体黏度较低,聚氨酯胶黏剂经水煮后的剥离力较高。当ω_(NCO)一定时,随着多元醇分子量减小,预聚体黏度增大,聚氨酯胶黏剂水煮前后的剥离力增加。在多元醇分子量为1 609 g/mol,ω_(NCO)为17%,R值为2.5时,水煮前后耐蒸煮聚丙烯流延膜层剥离力最高分别达到6.30 N和4.37 N。将该预聚体与多种B组分混合获得一系列聚氨酯胶黏剂,均满足国家标准GB/T 41168-2021对铝塑复合膜耐蒸煮性能的需求。

硅烷改性聚醚密封胶的配方研究和进展

本文叙述了硅烷改性聚醚(MS)预聚体的合成路线及主要区别,并以钟化MS产品为对象,从配方角度综述了预聚体、增塑剂、填料、偶联剂、催化剂和除水剂的类型或用量对MS密封胶力学性能和工艺性能的影响,最后总结了MS密封胶的市场现状并展望了未来发展趋势。

聚乳酸聚氨酯嵌段预聚体增韧PLA/TPU共混物

合成聚乳酸聚氨酯嵌段共聚物预聚体(PLA-b-PUP),以其作为聚乳酸(PLA)和热塑性聚氨酯(TPU)的活性相容剂,通过原位反应增容制备PLA/TPU/PLA-b-PUP超韧共混物.通过拉伸试验、冲击试验、SEM、FTIR、DSC和TGA研究共混物的力学性能、热性能和增韧机理.结果表明,PLA-b-PUP中的异氰酸酯基团与PLA和TPU上的活性基团发生反应,显著改善了PLA/TPU共混物两相界面的相容性.随着PLA-b-PUP的加入量增加,共混物中PLA的玻璃化转变温度和相对结晶度逐渐降低,当PLA-b-PUP的质量分数为PLA/TPU共混物的4%时,共混材料的断裂伸长率和缺口冲击强度分别达到无相容剂时的8.12和2.73倍,表现出良好的增容增韧效果.添加PLA-b-PUP后,共混物的初始分解温度有所降低,但最快分解温度有所提高.

聚氨酯预聚体中NCO含量测定方法的优化研究

为了快速准确地测定聚氨酯预聚体中异氰酸酯基的含量,对HG/T 2409—1992《聚氨酯预聚体中异氰酸酯基含量的测定》中的测定方法进行了深入研究,改变实验过程中的溶剂用量、反应时间和指示剂,从而选出最优测试条件。结果表明,取样量根据NCO含量参考HG/T 2409而变化,异丙醇用量50 mL、甲苯和0.2 mol/L二正丁胺-甲苯溶液的用量均为10 mL、反应时间10 min、指示剂选用溴甲酚绿为最优测试条件,该方法减少了实验带来的环境污染及测试成本,提高了测试效率,且精密度较高。

一种高强度单组分疏水型灌浆材料的研制

不同的聚醚多元醇与异氰酸酯合成预聚体,采用常温下相对挥发性较小的助剂与预聚体复配成单组分疏水型化学注浆液。通过对注浆液遇水反应生成固结体的抗压强度进行对比,同时考察了不同原料对施工工艺(可灌性、膨胀倍率等)的影响。结果表明,采用季戊四醇聚醚多元醇和聚合MDI合成的预聚体与增塑剂DBP等复配成的注浆液可以满足低黏度高强度的要求,适用于水利、大坝、矿山、民用等对防水加固要求较高的领域。

塑胶跑道用聚氨酯粉末胶粘剂的配比优化及性能研究

针对传统体育塑胶跑道用胶粘剂易挥发,造成环境污染的问题,提出一种环保型聚氨酯粉末胶粘剂的制备。对聚氨酯粉末胶粘剂的配比进行优化,并对其性能进行研究。结果表明,预聚体软段和硬段质量比为3.0∶1,—NCO基团与—OH基团的摩尔比(R值)为1.17,分散液为纳米级聚氟化乙烯丙烯分散液,通过三乙醇胺进行中和后,制备的聚氨酯粉末胶粘剂性能最佳,此时聚氨酯粉末胶粘剂施胶温度为85℃,初期剥离强度为70.4 N/cm,后期剥离强度为124 N/cm,拉伸强度为7.2 MPa,撕裂强度为11.8 MPa,伸长率为110%,硬度为50 HA,回弹率为38%,各项指标均满足GB 36246—2018标准要求,可以在体育塑胶跑道发挥作用。