沈之荃
过渡元素与稀土催化聚合合成顺丁橡胶和异戊橡胶领域
个性化签名
- 姓名:沈之荃
- 目前身份:
- 担任导师情况:
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学术头衔:
博士生导师, 中国科学院院士
- 职称:-
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学科领域:
高分子化学
- 研究兴趣:过渡元素与稀土催化聚合合成顺丁橡胶和异戊橡胶领域
沈之荃教授是我国过渡元素与稀土催化聚合合成顺丁橡胶和异戊橡胶领域专家。她1931年出生于上海市,1952年毕业于上海沪江大学化学系。1980年起先后在浙江大学化学系、高分子科学与工程学系任教,1995年当选为中国科学院院士。她曾被评为浙江省首届先进科技工作者、浙江省“十大杰出女性”、浙江省劳动模范;并被授予全国教育系统劳动模范、全国师德先进个人、第二届中国“十大女杰”、全国“三八红旗手”等荣誉称号。2001年荣获何梁何利基金科学与技术进步奖。
沈之荃教授在60年代早期率先研制三元镍系顺丁橡胶,从小试到大厂扩试,奠定了我国五个万吨级顺丁橡胶生产厂(如北京燕山橡胶厂、齐鲁石化橡胶厂等)聚合工艺基础,荣获1985年国家科技进步特等奖(此为集体协作成果,她为长春应化所主要获奖者之一)。
60-70年代首先在国内外开拓应用稀土化合物作丁二烯等双烯烃定向聚合催化剂及其合成橡胶研制。发展了有特色的催化聚合体系。研制成稀土顺丁橡胶和异戊橡胶等新品种,具有创新特色,协助研究单位及工厂建立了中试装置。获1982年国家自然科学二等奖,为第二获奖人。
80-90年代末持续推进和发展稀土络合催化聚合在高分子合成和材料方面新方向:开辟稀土催化聚合乙炔、苯乙炔光电导材料;首次提出制备高分子量环氧和环硫烷烃聚合物的新方法;研究成功了稀土催化聚合极性单体和烯烃齐聚和高聚;创造性地以稀土催化剂固定CO2、使CO2与环氧烷烃共聚制备出高分子量、热稳定和可降解聚碳酸酯,后由长春应化所继续这方面的研究,已取得成效。
上述系列成果荣获1993年国家自然科学三等奖和多项省部级奖。近年又成功地研究开发了多种新型稀土催化剂应用于丙交酯、ε-己内酯和环碳酸酯等开环均聚和共聚,以制备生物医用材料。“稀土环酯开环聚合”又获1998年教育部科技进步三等奖,以上均为第一获奖人。近期又将溶液聚合扩展到稀土催化丁二烯气相聚合方向,已取得可喜成果,获得发明专利。
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沈之荃, Jun Ling, Weipu Zhu, and Zhiquan Shen*
Macromolecules 2004, 37, 758-763,-0001,():
-1年11月30日
Copolymers of -caprolactone (CL) and trimethylene carbonate (TMC) have been synthesized through ring-opening polymerization using a novel initiator of scandium tris (2,6-di-tert-butyl-4-methylphenolate). CL and TMC polymerizations proceed via the "coordination anionic mechanism" with acyloxygen bond cleavage. Five kinds of copolymers with different structures of X, XB, AXB, AB, and BAXB are synthesized under different polymerization conditions and characterized by 1H NMR, GPC, and DSC, where X, A, and B denote as random blocks of CL and TMC, PTMC blocks, and PCL blocks, respectively.
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沈之荃, Jun Ling, Zhiquan Shen, * and Qiaohong Huang
Macromolecules 2001, 34, 7613-7616,-0001,():
-1年11月30日
The ring-opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) initiated with highly active single rare earth tris(2,6-di-tert-butyl-4-methylphenolate) (Ln(OAr)3, Ln=La, Nd, Dy, Y) is reported for the first time. The catalytic activities of various Ln(OAr)3 systems are decreasing in the following sequence: La>Nd>Dy~Y. PolyDTC (Mw=17.1×104, MWD=2.79) initiated by La(OAr)3 at [DTC]/[initiator]=1000 was obtained with a conversion of 97.9% within 1 h in toluene at 15℃. 1H NMR, GPC, and DSC are used to characterize the polymer's structure and to investigate the polymerization mechanism. PolyDTC obtained has no ether unit developed from CO2 elimination. The polymerization of DTC occurs according to a coordination anionic mechanism, and the ring is opened via acyl-oxygen cleavage leading to an Ln-O active center.
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沈之荃, Youqing Shen, † Zhiquan Shen, * Yifeng Zhang, and Kemin Yao‡
Macromolecules 1996, 29, 8289-8295,-0001,():
-1年11月30日
tically suppress the transesterification reactions by screening linear polymer chains from the active center during the polymerization of є-caprolactone (CL) with rare earth alkoxide. Therefore, isopropoxy rare earth diethyl acetoacetate ((EA)2LnOiPr Ln=Nd, Y) and Nd(OiPr)3-donor adducts (1,10-phenanthroline, 2,2¢-bipyridyl, 18-crown-6 ether) are excellent catalysts for the living polymerization of є-caprolactone, giving poly(є-caprolactone) (PCL) with a narrow molecular weight distribution. Block copolymerizations of є-caprolactone with trimethylene carbonate (TMC) and D,L-lactide (LA) have been attained successfully using (EA)2LnOiPr as catalyst. The characterizations by GPC, NMR, DSC, and polarizing microscope showed that the block copolymers, P(CL-b-TMC) and P(CL-b-D,L-lactide), have well-controlled sequences without random placement.
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【期刊论文】Characteristics and Mechanism of ε-Caprolactone Polymerization with Rare Earth Halide Systems
沈之荃, Youqing Shen*, Zhiquan Shen, Jianliang Shen, and Yifeng Zhang, Kemin Yao
Macromolecules 1996, 29, 3441-3446,-0001,():
-1年11月30日
Ring-opening polymerization of є-caprolactone catalyzed by rare earth halides and rare earth halide-epoxide has been carried out for the first time. It was found that rare earth halides have low activities for the polymerization of є-caprolactone, but in the presence of epoxide, rare earth halides are highly active for the bulk and solution polymerization of є-caprolactone, with high molecular weight poly-(-caprolactone) (PCL) formed. With the NdCl3-20PO system, PCL with a molecular weight of 22.4×104 can be easily obtained at 30℃, and the molecular weight of PCL can be increased to 42×104 at 60℃ with a catalyst efficiency of 100×104g of PCL/mol of NdCl3. The catalytic activities of the rare earth halides are affected by the kind of rare earth element, halogen, epoxide, amount of added epoxide, catalyst concentration, and polymerization temperature. It has been found that rare earth halides react with epoxide and produce halogen rare earth alkoxides: (X3-xLn{[OCH(R)CH2]yX}x, X=Cl, Br, I). A study on the polymerization mechanism showed that the resulting rare earth alkoxide bond initiates the polymerization of є-caprolactone via a "coordination-insertion" mechanism with acyl-oxygen bond cleavage of the monomer during the є-caprolactone polymerization catalyzed by rare earth halide-epoxide.
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沈之荃, Xianhai Chen, Zhiquan Shen, * and Yifeng Zhang
Macromolecules 1991, 24, 5305-5308,-0001,():
-1年11月30日
Copolymerzation of proplene oxide and carbon dioside was successfully carried out by using new rare-earth catalytic systems for the first time. It has been found that ternary rare-earth coordination catalysts composed of rare-earth phosphonat, triisobutylaluminum, and glycerine are effective catalysts for the copolymerixation. The system Y(P204)3-Al(i-Bu)3-glycerine shows the highest activity. The yield and interinsic viscosity of the copolymer depend significantly on the molar ratio of catalyst components and the reaction condition. The copolymers prepared were characterizaed by IR, 1HNMR, GPC. and DTA-TGA. It is showed that the copolymers obtained have a high molecular weight with a narrow molecular weithg distribution is showed that the copo;ymers obtained have a high molecular weitht with a narrow molecular weith distribution and a high thernmal stsbility. The carbonat unit content of the methanol-insoluble copolymer is as high as 30-40%.
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【期刊论文】Progress in Coordination Polymerization by Rare Earth Catalysts*
沈之荃, ZHIQUAN SHEN
Inorgaica Chimica Acta, 140 (1987) 7-14,-0001,():
-1年11月30日
Rare earth catalysts represem an unprecedemed case where either butadiene, isoprene or mixtures of butadiene and isprene can be polymerzed to elastomers with high content of cis-isomer and good properties. As high as 98% cis-polyacetylene films with metallic sheen can be prepared by rare earth catalysts are excellent as high cis-stereospecific polymerixzation catalysts for acetylenes. High molecular weight polyepoxides can also be prepared by rare earth catalysts.
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沈之荃, 杨慕杰, 蔡一平, 石明孝
中国科学,1983(2):119~130,-0001,():
-1年11月30日
本文首次研究了应用稀土化合物作乙炔定向聚合催化剂,发现除钜外所有15个镧系元素的环烷酸盐或2-乙基已基膦盐酸与三烷基铝基合成的络合催化剂都可以使乙炔写向聚合。其物点是乙炔在室温(30℃~0℃)下聚合,便能制得高顺式(80%~100%)、具有金属光汉的银灰色聚乙炔薄膜,显示稀土络合催化剂是一类合成高顺式聚乙炔极其方便的优良催化剂。本文报道乙炔在膦酸稀土盐和环烷酸稀土催化剂中定向聚合特征,以及用红外光谱、热分析、顺磁共振、X衍射、扫描电子显微镜及电阻率测定等对所制备的烯土聚乙炔薄膜初步表片的结果。
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【期刊论文】丁二烯和异戊二烯在氯化稀土-醇-三烷基铝催化体系中的共聚合
沈之荃, 宋襄玉, 肖淑秀, 杨吉坡, 阙香兰
中国科学,1981(11):21~31,-0001,():
-1年11月30日
本文研究了丁二烯-异戊二烯氯化稀土-三烷基铝催化体系中共聚合的规律。从聚合物的玻璃化温度和热裂解色谱证明了聚合产物确系共聚物。共聚速率方程可表示为:Rp=Kp[M]2[cat]。测定了丁二烯与异戊在Ⅲ-B族钪、钇和镧系元素在不同溶剂催化体系中的共聚速率常数、表观活化能及竞聚率。各种体系中都得到γ1(丁二烯)>1,γ(异戊二烯)<1,γ1·γ2接近于1的结果。用统计方法对共聚物的序列分布了讨论,证明共聚物中同种单体两单元以下连结的链节约占60-70%,说明生成的是无规共聚物。共聚物的组成和结构随条件变化而变化的范围不大,其中丁二烯与异成二烯链节的顺-1,4含量,一般都在95%以上。
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沈之荃, SHEN ZHIQUAN (SHEN TES-CHUAN), OQUANG JUN (OUYAN CHUN), WANG FUSONG (WANG FU-SUNG), HU ZHENYA (HU CHEN-YA), YU FUSHENG (YU FU-SHENG), and QIAN BAOGONG (CHIEN PAO-KUNG)
Journal of Polymer Science: Polymer Chemistry Edition Vol. 18, 3345-3357 (1980),-0001,():
-1年11月30日
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