萜烯环氧化反应的研究

以过氧乙酸作为环氧化剂对某些萜烯的环氧化反应进行了研究,讨论了环氧化反应中萜烯的结构和环氧化溶剂对反应速度的影响。     

硫磺/萜烯低聚物的制备及其热稳定性

以单萜烯烃(R)-(+)-苧烯为共聚单体,采用"反硫化"的方法将萜烯与单质硫磺直接混合进行本体熔融自由基共聚反应,得到具有良好溶解性的富硫低聚物。利用傅里叶变换红外光谱(FTIR)、核磁共振波谱(¹H NMR和¹³C NMR)、拉曼光谱(Raman)、元素分析(EA)和凝胶渗透色谱(GPC)对低聚物的化学结构和组成进行了表征,并且探索了投料比、反应时间以及反应温度对硫磺-萜烯低聚物(PSL)的结构和性能的影响。又采用热重分析(TGA)和差示扫描量热法(DSC)考察了该低聚物的热稳定性。结果表明:该聚合方法所制备产物具有良好的热稳定性、溶解性和粘接性。反应产物中硫磺的含量随硫磺投料的增多而增加。对于苧烯-硫磺的共聚物(PSL),当反应时间为2 h、反应温度为210℃时,所得产物综合性能最佳。     

沪酿醋酸杆菌1.01氧化醇为酸的反应研究

对沪酿1.01醋酸杆菌氧化醇为相应羧酸的反应进行了研究。以醇为底物,考察了溶剂、菌体浓度、pH值、反应时间和温度对收率的影响,并获得相应的最优反应条件:发酵温度37℃,pH 6,反应起始含菌量108个/mL、底物质量浓度为10 g/L,用盐酸调节体系pH值。为了探究脱氢酶对底物的选择性,分别对不同结构的伯醇、仲醇进行了催化氧化研究。实验结果表明:在有氧条件下沪酿1.01醋酸杆菌不仅能把乙醇氧化为乙酸用于制醋工业,而且能直接将多种伯醇氧化为相应的酸,而相应的醛在此过程中不被积累;该菌不能氧化仲醇为相应的酮。利用沪酿1.01醋酸杆菌氧化伯醇获得相应羧酸的方法具有反应条件温和、无污染、成本低、操作简便的特点。通过IR和1HNMR对产物结构进行了鉴定。     

异戊橡胶的环氧化改性及表征

研究了利用过氧乙酸将异戊橡胶分子链上的部分双键氧化成环氧基团的反应条件。在不同反应条件下异戊橡胶的环氧化程度不同,从而导致橡胶极性的变化,影响橡胶的性能。分别改变环氧化反应的温度、反应时间和pH值,并对所得产物通过红外光谱、核磁共振(1 H-NMR)及差示扫描量热分析(DSC)进行了表征和分析。     

环己烯绿色合成己二酸

以二水合钨酸钠与不同配体形成的络合物为催化剂,在相转移剂作用下,用30%的过氧化氢氧化环己烯合成己二酸。探讨了反应装置、催化剂用量、配体用量、相转移剂用量、反应时间、冷却时间对反应的影响。在优化条件下,即磷酸为配体,PEG600为相转移催化剂,220 mmol 30%H2O2氧化50 mmol环己烯,且n（Na2WO4...     

3,4-二(4′-氨基-3′,5′-二硝基苯基)氧化呋咱的合成及热性能

以4-甲氧基苯腈为原料,经肟化、重氮化、脱氮、关环、硝化及胺化等六步反应合成3,4-二(4′-氨基-3′,5′-二硝基苯基)氧化呋咱(DANBF),并优化了肟化、氧化呋咱成环及硝化反应的条件,用DSC、TG等对目标化合物的热性能进行了表征。结果表明,氧化呋咱成环反应的最适宜条件为:Na2CO3摩尔量为理论摩尔量的1.35倍,反应温度2～10℃,反应时间5h,收率58.1%,纯度不小于99.0%(HPLC)。芳基取代的氧化呋咱化合物具有较好的热稳定性。     

季铵盐型二醋酸碘苯的合成及其氧化反应研究

以对碘苯甲醛为起始原料,经还原、卤代、季铵化、氧化反应,成功合成了具有季铵盐结构的二醋酸碘苯,考察了这种新型的二醋酸碘苯对醇的氧化反应,这种二醋酸碘苯的合成简单,反应条件温和,收率较高,对醇的氧化具有产率高,条件温和,选择性较好等优点。     

氢氧化铈合成的新方法

研究了氢氧化铈合成的绿色方法. 以碳酸铈和醋酸为主要原料,最后获得氢氧化铈和醋酸钠. 探讨了过氧化氢的加入方式、过氧化氢的加入量、反应温度、醋酸铈的浓度、氢氧化钠的加入量对铈的氧化率的影响. 用扫描电子显微镜对氢氧化铈进行了表征. 铈的氧化率大于98 ,铈的收率大于99%.     

3,4-二(4'-氨基-3',5'-二硝基苯基)氧化呋咱的合成及热性能

以4-甲氧基苯腈为原料,经肟化、重氮化、脱氮、关环、硝化及胺化等六步反应合成3,4-二(4'-氨基-3',5'-二硝基苯基)氧化呋咱(DANBF),并优化了肟化、氧化呋咱成环及硝化反应的条件,用DSC、TG等对目标化合物的热性能进行了表征.结果表明,氧化呋咱成环反应的最适宜条件为:Na2CO3摩尔量为理论摩尔量的1.35倍,反应温度2～10℃,反应时间5h,收率58.1％,纯度不小于99.0％(HPIC).芳基取代的氧化呋咱化合物具有较好的热稳定性.     

NHPI和磺化酞菁钴催化的环己烷氧化反应

以N-羟基邻苯二甲酰亚胺(NHPI)和磺化酞菁钴(CoSPc)组成的催化体系对环己烷的氧化反应进行了研究,通过对反应时间、温度、NHPI用量、磺化酞菁钴用量的考察,得出环己烷氧化的最优反应条件为:反应时间2h,反应温度80℃,n(环己烷)∶n(NHPI)=10∶1,n(NHPI)∶n(CoSPc)=6∶1。在气相色谱上用内标法进行氧化反应产物的组成分析,产物除了环己酮和环己醇外,还发现了乙酸环己酯。在最优反应条件下,环己酮、环己醇、乙酸环己酯的产率及总产率为10.5%、1.1%、0.4%和12.0%。     

增黏树脂与弹性体SBS的相容性以及与热熔压敏胶性能的关系

热熔压敏胶(HMPSA)是一类不含溶剂的胶粘剂,在工业应用中占据很大的比重。工业上常用的增黏树脂有松香树脂、萜烯树脂和石油树脂三种。增黏树脂与热塑性弹性体SBS(苯乙烯/丁二烯/苯乙烯嵌段共聚物)的相容性存在一定的差异性,从工业角度重点研究和比较了增黏树脂的结构差异与性能之间的关系,并对其一般规律进行了探索。研究结果表明,当增黏树脂的软化点为100～110℃时,相应的HMPSA可获得较低的熔融黏度和较高的剥离强度,其初粘力为1～2cm;当增黏树脂的软化点为100℃时,剥离强度依次为含萜烯树脂HMPSA>含松香树脂HMPSA>含石油树脂HMPSA;当W(增黏树脂)= 210%时(相对于弹性体SBS而言),含石油树脂HMPSA的综合性能劣于含松香树脂(或含萜烯树脂)的HMPSA;当W(增黏树脂)≥210%时,HMPSA的熔融黏度低于10000mPa·s,但持粘力增强(即意味着内聚力增强)。     

Kinetics and Mechanism of the Cationic Polymerization of Trioxane. III. Copolymerization with Cyclic Formals

Kinetics and mechanism of three cationic copolymerization systems of trioxane (TO) and 1,3-dioxolane (DO) and/or 1,3,5-trioxepane (TOP) including TO/DO 2.0/0.1, TO/DO/TOP 2.0/0.1/0.055, and TO/TOP 2.0/0.1 in a unit of mol/L in 1,2-ethylene dichloride at 30°C were investigated via evaluations of yields of copolymers and conversions of monomer and comonomer(s) using a gravimetric method and gas chromatography, respectively. The reactivity of DO or TOP was higher than that of TO toward the copolymerizations. Two byproducts, namely, TOP (or DO) and tetroxocane (TOC), were formed during the copolymerization of TO and DO (or TOP). The equilibrium concentrations of TO, DO, TOP, and TOC were ca 0.40, 0.02, 0.02, and 0.02 mol/L, respectively, for the TO/DO and TO/TOP systems whereas relatively high equilibrium concentrations of DO and TOP at ca 0.035 mol/L were for the TO/DO/TOP system. As compared with TO homopolymer, the thermal stability of the copolymers was increased with increasing conversion. The finding that the TO/DO/TOP system having a relatively high amount of cyclic formals consumed in the copolymerization exhibited a relatively low thermal stability suggested that the transacetalization reactions proceeded mainly via oxocarbenium species other than cyclic oxonium species, as compared with the TO/DO and TO/TOP systems.     

Synthesis of gelatin–PVA adsorbent and its application in the separation of ginkgo flavonol glycosides and terpene lactones

Spherical adsorbents derived from the glutaraldehyde cross-linked hybrid of gelatin and polyvinyl alcohol (PVA) were synthesized, and their adsorption selectivity for ginkgo flavonol glycosides and terpene lactones was also investigated in detail. An adsorbent with an appropriate gelatin content can selectively adsorb flavonol glycosides with a high adsorption capacity based mainly on hydrogen bond interactions, while showing only a fairly low adsorption capacity for terpene lactones. A much higher adsorption affinity of flavonol glycosides than that of terpene was calculated from the adsorption isotherms. Thus, a simple preparative separation procedure for ginkgo flavonol glycosides and terpene lactones from a ginkgo leaf was established. An enriched extract containing flavonol glycosides of up to 60% and terpene lactones as low as 0.2% and an extract with a terpene lactones content up to 30% was prepared by this method, respectively.     

用于萜烯树脂合成的液体三氯化铝催化剂研究

本文找到了一种液体三氯化铝催化剂的生产方法,并对该催化剂用于萜烯树脂合成的条件进行了研究.结果表明:液体氯化铝作为萜烯树脂催化剂具有催化效果好、用量少,萜烯树脂软化点和得率高,色浑浅.     

聚合温度对萜烯基水性丙烯酸酯压敏胶的影响

通过萜烯树脂对乳液型丙烯酸酯压敏胶（PSA）进行改性。用预乳化半连续的方法合成改性丙烯酸酯乳液。考察了聚合温度对乳液的性能、聚合反应过程的转化率及压敏胶力学性能的影响,结果表明：聚合温度为81℃时,所制得乳液的性能最佳、单体的转化率最高及作为压敏胶的初黏力为25#,剥离强度5．64N·25mm^-1,持黏力为36h。同时用GPC、FTIR、DSC及TEM进行微观分析表明：聚合物的平均相对分子质量及相对分子质量分布分别随温度的升高变小变宽,适量的萜烯树脂参与各单体共聚且玻璃化温度为-30．63℃,乳胶粒的直径为200nm。     

Preparation of halloysite nanotubes coated with Eudragit for a controlled release of thyme essential oil

Active food packaging that releases active agents can extend the shelf‐life and improve the quality and safety of food products. Essential oils have been used as natural food preservatives due to their antioxidant, antimicrobial, and anti‐insect properties. However, one of the limitations of using essential oils as active agents is their high volatility. In this study, thyme essential oil, an active antioxidant agent, was encapsulated into halloysite nanotubes (HNTs) using a vacuum process to sustain the release rate and to solidify the thyme oil (TO) from a liquid state. Moreover, the TO‐loaded HNT capsules (TO/HNT capsules) were coated with Eudragit EPO polymer to avoid burst release and to prolong the release time. The morphology of the prepared samples was characterized using SEM, TEM, and nitrogen adsorption–desorption analysis by BET method. Zeta potential and FTIR analysis were used to verify the encapsulation of the TO and the Eudragit EPO polymer coating of TO/HNT capsules. After Eudragit EPO polymer coating of TO/HNT capsules, the surface charge of the samples was converted from ?17.5 ± 0.2 mV to +19.4 ± 1.5 mV. The amount of encapsulated TO was determined using a GC‐FID. Encapsulation efficiency and payload of TO/HNT capsules prepared using 26.7% (w/v) TO solution were 14.94% and 14.58%, respectively. The encapsulated TO was released in a sustained manner for 96 h. In addition, antioxidant activity of the samples was evaluated using a DPPH assay and a reducing power assay. In both two assays, the antioxidant activity of the TO/HNT capsules was increased along with the increasing concentration of TO/HNT capsules. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42771.     

深山含笑和乐昌含笑叶片挥发油的成分分析及性能测定

采用超临界二氧化碳萃取法提取深山含笑和乐昌含笑叶片挥发油,应用GC-MS技术测定挥发油的成分并对其DPPH自由基清除能力和还原能力等抗氧化指标进行测定.结果表明:深山含笑萜类为35.35%,酯类为15.12%,醇类为9.09%,其余37.02%为萜烯类含氧衍生物.乐昌含笑萜类为28.49%,酯类为11.12%,醇类为1.94%,其余54.55%为萜烯类含氧衍生物.两种含笑叶片挥发油质量浓度为50mg/L时DPPH自由基清除能力达到饱和,且挥发油质量浓度越大还原能力越强.通过与常用抗氧化剂进行比较,发现两种含笑叶片挥发油的抗氧化能力均强于植酸PA、没食子酸丙酯PG和抗坏血酸Vc.     

苯乙烯-异戊二烯嵌段聚合物热熔压敏胶性能影响因素探讨

用不同种类增粘树脂、不同牌号苯乙烯-异戊二烯嵌段聚合物(简称SIS)制备SIS热熔压敏胶,考察不同种类增粘树脂、不同牌号SIS及萜烯树脂含量对SIS热熔压敏胶性能的影响,结果表明:萜烯树脂是改性SIS热熔压敏胶适宜的增粘树脂,当萜烯树脂在SIS热熔压敏胶中含量达50%时,SIS热熔压敏胶性能较佳,随不同牌号SIS中两嵌段SI含量的增加,SIS热熔压敏胶的剥离强度有所增加,持粘力有所下降。     

新型蔬菜果园粘虫胶的制备和性能研究

蔬菜果园粘虫胶的运用是现代绿色高效农业发展中重要的物理手段。选用不同分子质量的聚异丁烯、矿物油、加氢石油树脂及萜烯树脂原料,通过优化配方,制备了性能优异的用于涂覆胶板的无溶剂高粘性环保型粘虫胶。测试了粘虫胶的熔融黏度、初粘性、粘性保持时间、抗垂流性能等,结果表明,此胶可长时间用于室外涂覆粘虫板。     

Photocurable ceramic/monomer feedstocks containing terpene crystals as sublimable porogen for UV curing-assisted 3D plotting

This study presents a novel strategy to construct ceramic structures comprised of microporous filaments using photocurable ceramic/monomer feedstocks containing terpene crystals as sublimable porogens for UV curing-assisted 3D plotting technique. The biphasic calcium phosphate (BCP) feedstock, composed of frozen terpene crystals surrounded by BCP/UDMA walls, could be favorably extruded through a fine nozzle and then effectively photopolymerized by UV light. Thus, green filaments with high shape retention could be obtained. In addition, a number of pores could be created in BCP filaments after removing terpene crystals via freeze-drying and the porosity could be tailored by adjusting terpene content in BCP feedstocks. This approach allowed for the construction of dual-scale porous structures comprising microporous filaments in a periodic pattern, with tailored overall porosities and compressive strengths. Several types of self-supporting structures were also successfully constructed using our approach.