丁腈橡胶对聚甲醛树脂的增韧机理研究

研究了丁腈橡胶（ＮＢＲ） 对聚甲醛（ＰＯＭ） 树脂的增韧机理,并比较了ＰＯＭ／ＮＢＲ 体系和ＰＯＭ／ 热塑性聚氨酯（ＴＰＵ） 体系的异同．结果表明,高丙烯腈（ＡＮ） 含量的ＮＢＲ 有着和ＴＰＵ 相近的溶度积参数,且其分子上的氰（ＣＮ） 基或双键对ＰＯＭ 分解时产生的甲醛及大分子自由基的捕捉作用,有利于改善ＮＢＲ 和ＰＯＭ 之间相容性,因而可和ＰＯＭ 树脂形成良好的合金体系;当ＮＢＲ 含量达４０ｗｔ％ 时,ＰＯＭ／ＮＢＲ 体系出现脆 韧转变,从逾渗机制、剪切带机制、类互穿网络（ＩＰＮ） 作用机制等角度进行考察的结果证明,ＮＢＲ 对ＰＯＭ 树脂的增韧行为以及ＰＯＭ／ＮＢＲ 共混合金体系的脆 韧转变规律与ＰＯＭ／ＴＰＵ 体系相一致．     

STRUCTURAL EVIDENCE FOR THE METAL ION BRIDGED LIGANDLIGAND INTERACTION：THE X－RAY CRYSTAL STRUCTURE OF ［（2，2＇－BIPYRIDYL）（PHENYLMALONATE）COPPER（Ⅱ）］ TRIHYDRATE

ＳＴＲＵＣＴＵＲＡＬＥＶＩＤＥＮＣＥＦＯＲＴＨＥＭＥＴＡＬＩＯＮＢＲＩＤＧＥＤＬＩＧＡＮＤＬＩＧＡＮＤＩＮＴＥＲＡＣＴＩＯＮ：ＴＨＥＸ－ＲＡＹＣＲＹＳＴＡＬＳＴＲＵＣＴＵＲＥＯＦ［（２，２＇－ＢＩＰＹＲＩＤＹＬ）（ＰＨＥＮＹＬＭＡＬＯＮＡＴＥ）ＣＯＰ...     

IN－SITU FTIR AND UV－VISIBLE－NEAR－IR SPECTROELECTROOHEMICAL STUDIES OF MIXED－VALENCE ISOPOLYANION Mo＿6O＿（19）￣（3－） IN APROTIC MEDIA

ＩＮ－ＳＩＴＵ　ＦＴＩＲ　ＡＮＤ　ＵＶ－ＶＩＳＩＢＬＥ－ＮＥＡＲ－ＩＲ　ＳＰＥＣＴＲＯＥＬＥＣＴＲＯＯＨＥＭＩＣＡＬ　ＳＴＵＤＩＥＳ　ＯＦ　ＭＩＸＥＤ－ＶＡＬＥＮＣＥ　ＩＳＯＰＯＬＹＡＮＩＯＮ　Ｍｏ＿６Ｏ＿（１９）￣（３－）　ＩＮ　ＡＰＲＯＴＩＣ　Ｍ...     

TRANSFER HYDROGENATION OF KETONES BY PROPAN－2－OL OVER POLY（PHENYLENE OXIDE） ANCHORED RUTBENIUM CATALYST

ＴＲＡＮＳＦＥＲ　ＨＹＤＲＯＧＥＮＡＴＩＯＮ　ＯＦ　ＫＥＴＯＮＥＳ　ＢＹ　ＰＲＯＰＡＮ－２－ＯＬ　ＯＶＥＲ　ＰＯＬＹ（ＰＨＥＮＹＬＥＮＥ　ＯＸＩＤＥ）　ＡＮＣＨＯＲＥＤ　ＲＵＴＢＥＮＩＵＭ　ＣＡＴＡＬＹＳＴ￥ＨａｎＲｏｎｇＧＡＯ；ＹｕｎＸＵ；ＳｈｉＪ...     

THE CHIRAL SELECTIVITY IN ACROSS－MEMBRANE TRANSPORT OF 1，2－DIAMINOCYCLOHEXANE PLATINUM（II）COMPLEXES AND THE CONTRIBUTION OF LEAVING GROUPS

ＴＨＥＣＨＩＲＡＬＳＥＬＥＣＴＩＶＩＴＹＩＮＡＣＲＯＳＳ－ＭＥＭＢＲＡＮＥＴＲＡＮＳＰＯＲＴＯＦ１，２－ＤＩＡＭＩＮＯＣＹＣＬＯＨＥＸＡＮＥＰＬＡＴＩＮＵＭ（ＩＩ）ＣＯＭＰＬＥＸＥＳＡＮＤＴＨＥＣＯＮＴＲＩＢＵＴＩＯＮＯＦＬＥＡＶＩＮＧＧＲＯＵＰＳ￥...     

A COMPARATIVE STUDY ON THE PHOTOVOLTAIC PROPERTIES OF BUCKMINSTERFULLERENE （C60） AND ITS ANION SALT

ＡＣＯＭＰＡＲＡＴＩＶＥＳＴＵＤＹＯＮＴＨＥＰＨＯＴＯＶＯＬＴＡＩＣＰＲＯＰＥＲＴＩＥＳＯＦＢＵＣＫＭＩＮＳＴＥＲＦＵＬＬＥＲＥＮＥ（Ｃ６０）ＡＮＤＩＴＳＡＮＩＯＮＳＡＬＴ￥ＺｈａｎＪｕｎＹＵ；ＰｅｎｇＺＨＡＮＧ；ＬｉｎＳｏｎｇＬＩ；ＤｅＪｕｎＷＡＮ...     

RUTHENTUM（Ⅱ）COORDINATION COMPOUNDS WITH POLYPYRIDINE （Ⅲ）： STEREOSELECTIVITY OF TRIS（PHENANTHROLINE）RUTHENIUM BINDING IN DNA

ＲＵＴＨＥＮＴＵＭ（Ⅱ）ＣＯＯＲＤＩＮＡＴＩＯＮＣＯＭＰＯＵＮＤＳＷＩＴＨＰＯＬＹＰＹＲＩＤＩＮＥ（Ⅲ）：ＳＴＥＲＥＯＳＥＬＥＣＴＩＶＩＴＹＯＦＴＲＩＳ（ＰＨＥＮＡＮＴＨＲＯＬＩＮＥ）ＵＴＨＥＮＩＵＭＢＩＮＤＩＮＧＩＮＤＮＡ￥ＬｅｉＷＡＮＧ；Ｇｕａｎ...     

THE STUDY ON EFFECT OF PARTICLE SIZE IN BOTANICAL STANDARD SAMPLE ANALYSIS BY SLURRY SAMPLING AND FLUORINATION ELECTROTHERMAL VAPORIZATION（ETV）－ICP－AES

ＴＨＥＳＴＵＤＹＯＮＥＦＦＥＣＴＯＦＰＡＲＴＩＣＬＥＳＩＺＥＩＮＢＯＴＡＮＩＣＡＬＳＴＡＮＤＡＲＤＳＡＭＰＬＥＡＮＡＬＹＳＩＳＢＹＳＬＵＲＲＹＳＡＭＰＬＩＮＧＡＮＤＦＬＵＯＲＩＮＡＴＩＯＮＥＬＥＣＴＲＯＴＨＥＲＭＡＬＶＡＰＯＲＩＺＡＴＩＯＮ（ＥＴＶ）...     

NOVEL REACTIONS BETWEEN CHROMIUM CARBYNE COMPOUNDS AND DICOBALT OCTACRBONYL

ＮＯＶＥＬ　ＲＥＡＣＴＩＯＮＳ　ＢＥＴＷＥＥＮ　ＣＨＲＯＭＩＵＭ　ＣＡＲＢＹＮＥ　ＣＯＭＰＯＵＮＤＳ　ＡＮＤ　ＤＩＣＯＢＡＬＴ　ＯＣＴＡＣＲＢＯＮＹＬＨｏｎｇＳｕｉＳＵＮ；ＹｕａｎＱｉＹＩＮ；ＸｉａｏＺｅｎｇＹＯＵａｎｄＹｏｎｇＪｉａｎｇＬＩＵ．（Ｓ...     

THE CATALYTIC PROPERTIES OF POLY（2－VINYLPYRIDINE）AND ITS QUATERNARY AMMONIUM SALT BOUND Rh（Ⅰ） COMPLEXES FOR CARBONYLATION OF METHANOL

ＴＨＥＣＡＴＡＬＹＴＩＣＰＲＯＰＥＲＴＩＥＳＯＦＰＯＬＹ（２┐ＶＩＮＹＬＰＹＲＩＤＩＮＥ）ＡＮＤＩＴＳＱＵＡＴＥＲＮＡＲＹＡＭＭＯＮＩＵＭＳＡＬＴＢＯＵＮＤＲｈ（Ⅰ）ＣＯＭＰＬＥＸＥＳＦＯＲＣＡＲＢＯＮＹＬＡＴＩＯＮＯＦＭＥＴＨＡＮＯＬＬｉＸｉａｏｂ...     

大豆油树脂基泡沫塑料的力学性能与生物降解性研究

用丙烯酸酯化环氧大豆油(AESO)和甲基丙烯酸甲酯(MMA)经自由基共聚合制得一种新型的植物油基泡沫塑料.对AESO/MMA泡沫塑料的压缩性能的各种影响因素进行了细致研究,结果表明,所得泡沫塑料的压缩性能取决于AESO/MMA的比例、引发剂和促进剂的浓度.AESO泡沫塑料具有与传统不饱和聚酯泡沫塑料相似的压缩强度,而且比后者具有更高的韧性,同时这类植物油基泡沫塑料有着良好的生物降解性.     

Fundamental studies of grafting reactions in free radical copolymerization. III. Grafting of styrene,acrylate, and methacrylate monomers onto cis-polybutadiene using benzoyl peroxide initiator in solution polymerization

Benzoyl peroxide (BPO), due to its higher radical reactivity as compared to AIBN, is known to promote grafting onto cis-polybutadiene. Switching from AIBN to BPO initiator made a dramatic difference in the extent of grafting for styrene and methacrylate monomers, but only a modest difference for acrylate monomer. For styrene and methacrylate monomers, graft site formation is due to BPO initiator radical attack onto the backbone via allylic hydrogen abstraction. Significant levels of grafting are achieved and depend upon the relative concentrations of monomer and backbone polymer but not upon the level of initiator. For acrylic monomer, graft site formation was found to be due to polymer radical attack at the double bond in the backbone. Abstraction of allylic hydrogen also occurs but results in retardation of the overall reaction rate. Graft level was dependent upon initiator and back-bone polymer concentrations but not upon monomer concentration. The effective role of the initiator is only to produce polymer radicals; the BPO has no direct role in the formation of effective graft sites. © 1995 John Wiley & Sons, Inc.     

Properties of polyurethane-polystyrene graft copolymer membranes used for separating water-ethanol mixtures

Polyurethane prepolymers (PU) based on hydrophilic poly(ethylene glycol) (PEG), hydroxypropyl acrylic acid (HPA), 2,4-toluene diisocyanate (TDI), and butanediol (BDO) were prepared by one-step polymerization with butanediol as the chain extender. Polyurethane-polystyrene graft copolymers (PU-g-PS) were synthesized by free radical copolymerization of PU with styrene (ST), 2,2′-azobisisobutyronitrile (AIBN) was used as initiator and toluene as solvent. Experimental results showed that the crosslinked membranes of PU-PS graft copolymers could be used for separating ethanol-water mixtures. The highest value of the separation factor (α) of the crosslinked separation membranes can reach 17.3. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were used to characterize the properties of PU-PS crosslinked membranes.     

Influence of caged bicyclic phosphate and CaCO3 nanoparticles on char-forming property of PU rigid foams

Char-forming property of PU rigid foams, which can be assessed by char residue (%) when PU is burned at certain temperature, was studied by TG and DTG. The results showed that pure PU rigid foam had low char residue of only 17%, while 33% of char residue was achieved when PU rigid foam was modified by adding 8 wt% of 1-oxo-2,6,7-trioxa-1-phosphabicyclo[2,2,2] octane (PEPA), which is a caged bicyclic phosphate. The experiment results of FTIR and XPS showed that the PEPA modified PU rigid foam could be dehydrogenated and dehydrated at temperature between 380 and 450 °C, resulting in the increase of char residue of PU rigid foam. Further study also revealed that the addition of CaCO₃ nanoparticles could enhance the char stability when the PEPA modified PU rigid foam was being burned. The mechanism was investigated and it was found that the enhanced char stability could be attributed to the limited permeation of oxygen caused by the formation of calcium phosphate and calcium pyrophosphate by the reaction of PEPA and CaCO₃ at high temperature, which were covered on or buried in the char layer.     

Rigid polyurethane foams reinforced with disilanolisobutyl POSS: Synthesis and properties

This work reports the synthesis of rigid polyurethane (PU) foams modified by disilanolisobutyl polyhedral oligomeric silsesquioxane (DSIPOSS). This open‐cage nanostructure silsesquioxane has 2 hydroxyl groups and therefore can be chemically built directly in the PU backbone to form hybrid polyurethane‐POSS foam. Synthesis procedure using polymeric 4,4′‐diphenylmethane diisocyanate, polyetherol, and DSIPOSS has been elaborated, and the influence of POSS on the cell structure, closed cell content, apparent density, thermal conductivity, and compression strength of the rigid polyurethane composites has been evaluated. The hybrid composite foams containing 1.5 and 2.0 wt% DSIPOSS showed a reduced number of cells and an increased average area of foam cells in comparison with the unmodified PU, while the addition of 0.5wt% of DSIPOSS causes an increase in the number of cells of the foam as compared with the reference and thus a reduction in the average area of cells. X‐ray microtomography provided data on the porous structure of polyurethane hybrid materials, including reduction of the pore surface area. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy analysis revealed a good homogenization of DSIPOSS in polyurethane matrix. Thermogravimetric analysis results have shown that incorporation of POSS nanoparticles into PU foam does not significantly change the degradation process. The compressive strength of PUF‐POSS hybrids in the direction parallel and perpendicular to the direction of foam rise is greater than the strength of the reference foam already for the lowest DSIPOSS content.     

RAFT聚合合成高分子量嵌段聚合物

以合成高分子量聚合物为目标,以苯基二硫代乙酸-1-苯基乙酯(PEPDTA)作为RAFT试剂,研究引发剂的种类(偶氮二异丁腈(AIBN)、1-1′-偶氮环己腈(ACC))、用量及聚合温度对苯乙烯/丙烯酸丁酯RAFT共聚合过程和聚合物结构的影响.结果发现,由于体系中RAFT浓度很低,相应的引发剂浓度要比传统自由基聚合低得多,只有采用较高的聚合温度和低分解速率常数的引发剂(ACC),才能制得无活性聚合物分率低(<0.1)、分子量高的聚合物,并进一步得到杂质含量少、分子量分布窄的嵌段聚合物.     

聚氨酯/环氧树脂互穿网络硬质泡沫塑料反应过程和微观结构

聚氨酯／环氧树脂互穿网络(PU／EPIPN)硬泡中异氰酸根的消耗速度较纯PU硬泡高，是由于环氧树脂的固化荆同时也是异氰酸根反应的催化荆。而PU／EP IPN硬泡中环氧基的反应速度和反应程度均较纯EP网络低，归因于互穿网络对基团扩散的阻碍。在互穿网络硬泡形成过程中，存在环氧开环中所新产生的羟基与异氰酸根的反应、大分子多元醇中羟基与环氧基的反应以及异氰酸根与环氧基形成嗯唑烷酮的反应三种形成网络间的化学键的途径。同时由于PU／EPIPN硬泡高度的交联，使得IPN硬泡中两个网络具有良好的相容性。动态力学性能表明所有IPN样品都只有一个玻璃化温度。透射电镜表明IPN样品无明显的相界面。     

Synthesis and radical polymerization behavior of bifunctional vinyl monomer derived from N‐vinylacetamide and p‐chloromethylstyrene

The radical polymerization of N‐(p‐vinylbenzyl)‐N‐vinylacetamide ( 1 ) prepared by the reaction of N‐vinylacetamide with p‐chloromethylstyrene was carried out by using radical initiators such as AIBN or BPO in benzene, chlorobenzene, or bulk. As a result, poly 1 was successfully isolated by dialysis (yield, 10–36%). The crosslinking reaction of poly 1 was carried out at 60–100 °C for 8 h. By using a radical initiator such as AIBN or BPO (3 mol %), the crosslinking reaction proceeded (yield, 63–79%). Moreover, the crosslinking reaction of poly 1 proceeded at 100 °C without a radical initiator in 50% yield. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2714–2723, 2006     

偶氮复合发泡剂对交联聚氯乙烯泡沫结构和性能的影响

采用异氰酸酯和环氧树脂作为交联剂,偶氮二异丁腈（AIBN）和偶氮二甲酰胺（AC）作为发泡剂制备了交联聚氯乙烯泡沫材料。 通过扫描电子显微镜分析了两种发泡剂的粒径、比例以及用量对泡孔结构的影响。 结果表明,AIBN的粒径对泡沫的泡孔结构影响不大,但其用量增加导致泡沫密度减小;AC的粒径对泡孔结构产生一定的影响,最优的粒径范围为8～20 μm,并且随着用量增加,泡孔尺寸变小,但对密度影响不大。 采用DSC研究了AIBN和AC在预混料中的分解情况,提出了两种发泡剂影响泡沫的泡孔结构的机理。 对泡沫材料力学性能的分析表明,泡沫的强度随密度的增加而增加,剪切变形则在60～80 kg/m3密度范围内出现最大值。     

Preparation of Polystyrenylphosphonous Acid of Low Polymerization Degree and Influence of Initiators upon the Free Radical Reaction Mechanism

Organophosphorus chemistry plays an important role in chemical engineering, pesticide, medicine and catalysis1,2. In recent years, after extensive research and widespread application, synthesis and preparation of new organophosphorus compounds have attracted increasing research interest. Polystyrene is a very important and versatile matrix or precursor of various kinds of functional polymer. Usually, introducing of phosphonic PO3H2 or phosphinic PO2H2 group into polystyrene matrix through…