Controlled alternating copolymerization of St with MAh in the presence of DBTTC

The copolymerization of styrene (St) with maleic anhydride (MAh) performed at 22 °C in the presence of dibenzyl trithiocarbonate exhibits controlled nature evidenced by: narrow molecular weight distribution, controlled molecular weight and first-order polymerization kinetics. The composition analysis of the copolymers obtained by ¹³C NMR spectra shows the molar fraction of St in obtained copolymers is almost equal to 0.5 throughout the copolymerization. The sequence structure of the copolymer was obtained from DEPT experiments by recording the spectra at π/4 and 3π/4, and then combining them together, the results showed that the copolymers obtained possessed well-defined alternating structure. The experiment shows that charge-transfer-complex formed from St and MAh participates in both initiation and chain growth throughout the copolymerization.     

一步法合成N-1,3-二羟基丙烷-2-基烷基乙酰胺

以5-氨基烷基-2,2-二甲基-1,3-二噁烷为起始原料, 乙酸酐为酰化剂, 一步法选择性地合成氨基二醇类氨基乙酰化产物N-1,3-二羟基丙烷-2-基烷基乙酰胺. 该方法操作简便, 收率高. 所合成的4个新化合物的结构均经FTIR, ¹H NMR, ¹³C NMR及HRMS确证. N-3-(1,3-二羟基丙烷-2-基)丙基乙酰胺(1a)作为关键的中间体, 可以用于HIV-1 Tat/ PCAF BRD抑制剂4的合成.     

SYNTHESIS OF MESOPOROUS POLY(STYRENE-co-MALEIC ANHYDRIDE)/SILICA HYBRID MATERIALS VIA A NONSURFACTANT-TEMPLATED SOL-GEL PROCESS*

Mesoporous poly (styrene-co-maleic anhydride)/silica hybrid materials have been prepared. The synthesis wasachieved by the HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and styrene-maleic anhydride copolymerin the presence of 3-aminopropyl triethoxysilane (APTES) as a coupling agent and citric acid as a nonsurfactant template orpore-forming agent, followed by ethanol extraction. Characterization results from nitrogen sorption isotherms and powder X-ray diffraction indicate that polymer-modified mesoporous materials with large specific surface areas (e.g. 900 m~2/g) andpore volumes (e.g. 0.6 cm~3/g) could be prepared. As the citric acid concentration is increased, the specific surface areas, porevolumes and pore diameters of the hybrid materials increase.     

Synthesis of the Biomimetic Polymer： Aliphatic Diamine and RGDS Modified Poly（d,l-lactic acid）

A novel poly（d, /-lactic acid） （PDLLA） based biomimetic polymer was synthesized by grafting maleic anhydride, butanediamine and arg-gly-asp-ser （RGDS） peptides onto the backbone of PDLLA, aiming to overcome the acidity and auto-accelerating degradation of PDLLA during degradation and to improve its biospecificity and biocompatibility. The synthetic copolymer was characterized by FTIR, ^13C NMR and amino acid analyzer （AAA）.     

Grafting of maleic anhydride to hydrocarbons below the ceiling temperature

Maleic anhydride has been grafted to eicosane and squalane at 60–80°C using 1,2-dichlorobenzene as solvent and benzoyl peroxide as initiator. These hydrocarbons are low molecular weight models for hydrocarbon polymers containing secondary and tertiary hydrogen atoms. In the absence of the hydrocarbon and with monomer concentrations of the order of 1M, low molecular weight poly(maleic anhydride) is formed. On addition of the hydrocarbon, the main product is grafted material and very little homopolymer is formed. The grafts consist primarily of single succinic anhydride units but some of them are short poly(maleic anhydride) chains. Ceiling temperature considerations control the formation of homopolymer in the absence of hydrocarbon substrate. In the presence of eicosane or squalane, initiation of grafting proceeds by hydrogen abstraction from the hydrocarbon. The main factor controlling graft length is then the ratio of the rates of intramolecular hydrogen abstraction and of monomer addition to succinic anhydride radicals © 1995 John Wiley & Sons, Inc.     

以马来酸酐为原料催化合成富马酸二甲酯

用马来酸酐与甲醇为原料,在浓盐酸为主的复合催化剂的作用下,经一步反应合成富马酸二甲酯.讨论了催化剂用量、酯化时间、异构时间、醇与酸酐比等因素对反应的影响.最适宜的反应条件为:n(甲醇):n(酸酐)=4:1,异构时间0.7h,酯化时间4h,催化剂用量为马来酸酐质量的3.5%.     

聚合条件对N-羧基-L-丙氨酸-环内酸酐开环聚合产物分子量的影响

用光气法制备了N-羧基-L-丙氨酸-环内酸酐(L-Alanine NCA).系统研究了L-Alanine NCA开环聚合反应过程中引发剂、溶剂、温度对聚合物分子量的影响.用硝基苯作溶剂,三乙胺作引发剂,所得聚合物特性粘度[η]=1.18.实验中发现,L-Alanine NCA可以顺利地进行热聚合反应。反应具有速率快,转化率高,分子量大的特点。甲苯溶剂中反应5小时所得聚合物[η]=2.35,高于采用引发剂的聚合体系产物的相应值。     

2-(4-氯苯基)-3-甲基丁酸的消旋

以酸酐及有机惰性溶剂作混合溶剂，少量叔胺等作催化剂，2-(4-氯苯基)-3-甲基丁酸能在比较温和的条件下基本完全消旋，收率接近90％。     

稀土配位催化马来酸酐-苯乙烯-N-苯基马来酰亚胺三元共聚合

采用稀土配位催化剂研究了马来酸酐、苯乙烯和N 苯基马来酰亚胺的三元共聚合反应 .考察了Al La物质的量的比、不同稀土元素、催化剂浓度、聚合反应时间、单体配比等因素对共聚合反应的影响 .利用核磁、红外、热分析等方法对共聚物进行了初步的表征     

马来酸酐与乙酸乙烯酯交替共聚合反应的研究

本文研究了马来酸酐（MAn）在过氧化苯甲酰（BP）引发作用下与醋酸乙烯酯（VAc）的交替共聚反应。红外光谱证明了交替共聚物的结构，分析结果表明共聚物是由反应单体技1：1摩尔比例组成。当c（BPO）＝6．8×10~（－3）moi／L，c（VAc）＝3．4×10~（－3）mol／L，p（MAn）＝32．7g／L，63～65℃反应18小时，转化率可达92％以上。