SYNTHESIS AND CATIONIC RING-OPENING POLYMERIZATION OF 1, 4-ANHYDRO-2, 3-DI-O-(P-AZIDOBENZYL)-α-D-RIBOPYRANOSE

New highly stereoregular 2, 3 -di- O-(p-azidobenzyl )-(1 →5 ) - α-D -ribofuranan was synthesized byselective ring-opening polymerization of 1, 4-anhydro-2, 3 - di-O -(p-azidobenzyl )-α-D -ribopyranose(ADABR) using phosphorus pentafluoride or tin tetrachloride as catalyst at low temperature indichloromethane. The monomer was obtained by the reaction of p - bromomethyl -phenyleneazide with 1, 4 -anhydro-α-D-ribose in DMF. The structure of poly(ADANR) was identified by specific rotation and ~(13)C-NMR spectroscopy. Acid chloride-AgCl_4 complex catalyst such as CH_2=C(CH_3)C~+OClO_4~- used in thepolymerization resulted in polymers with mixed structures, i.e. (1→5)-α-D-ribofuranosidic and (1→4)-β-D-ribopyranosidic units. However, with C_6H_5C~+OClO_4~- as catalyst, pure (1→5)-α-D-ribofuranan was obtained.The effects of catalyst, polymerization temperature and time on polymer stereoregularity were examined, andthe mechanism of the ring-opening polymerization was discussed.     

THE STUDY OF COPOLYMERIZATION OF p-DIETHYNYLBENZENE WITH OTHER ACETYLENIC DERIVATIVES

The copotymerizations of p-diethynyibenzene(PDEB)with phenytacetylene(PHA),4,4'-diethynytbiphenyt(DEBP)or m-diethynylbenzene(MDEB)are studied in various mole ratios of monomers.The sotubitity pa-rameter(σ_p),swellabitity(θ_p),Huggins parameter(X),density (d_4~(25))and the average motecutarweights between crosstinkof obtained copotymers are measured.The IR spectra of these copolymersare recorded.The mechanism about the polymerization of acetytenic derivatives initiated by(Ph_3P)_2PdCl_2is discussed.     

THEORETICAL STUDY OF CHAIN MICROSTRUCTURE OF COPOLYMERS IN ANIONIC COPOLYMERIZATION WITH CONSTANT MONOMER RATIO

In this work, the sequence distribution of copolymers generated in anionic copolymeriza-tion with a constant comonomer ratio has been theoretically investigated by means of non-steady state kinetic technique. The microstructural parameters of the copolymer, such as se-quence distribution functions, the average length of sequence and mole fractions of dyads andtriads, are derived by rigorously solving the kinetic differential equations. Furthermore, theseparameters are connected with reaction time and initial conditions and therefore become pre-dictable.     

STUDY ON POLYMERIZATION OF OILLESS ALKYD RESIN WITH PHENYLTRIETHOXYSILANE

Oilless alkyd resin modified with the silicoorganic compounds has been obtainedsuccessfully by polymerization.At appropriate proportion of silicoorganic compounds,thepolymerized product has higher hardness and lustre than that of oilless alkyd resin.     

A MODEL STUDY ON MODE OF BONDING OF CISPLATIN WITH DNA

The interaction of cis-[Pt(NK_3)_2Cl_2] with nucleosides, as constituents of DNA, was studled by spectrophotometric, ~(13)C NMR and CNDO/2 methods. The apparent stability constants of the complexes formed and the initial rate of formation were determined. The sites of binding of nucleoside (or nucleotide) with Cisplatin were ascertained and the electronic structure of the model coordination compounds of Cisplatin and guanine was calculated by MO approach. On the basis of the obtained results, the mechanism of the antitumour action of Cisplatin was discussed, and a new possible mode of bonding of Cisplatin with DNA was proposed.     

STUDY ON SYNTHESIS OF SUPERABSORBENT OF STARCH-GRAFT-POLY(KAA-CO-AAm) BY INVERSE SUSPENSION COPOLYMERIZATION

The First Author: LIN Songbai, Male(1957-), Born in Fujian Province, Associate Prof., Post doctor. 1. INTRODUCTION In the past 20 years, superabsorbent polymers (SAP) have achieved a large worldwide market [1~3]. Statistics indicates that the worldwide…     

STUDY ON 1,2,3-DIAZAPHOSFHOLE V THE REACTION OF 1,2,3-DIAZAPHOSPHOLE WITH 2-BUTYNE-1,4-DIOL

2-Acetyl-5-methyl-2H-1,2,3—diaraphosphole 1 reacted with 2—butyne—1, 4—diol to form a tricoordinated phosphorus compound 7, which then rearranged to a novel 2, 3-disubstituted-1, 3-diene.Similar rearrangement has been observed when diphenylchloropbosphine reacted with 2-butyne—1,4-diol     

EFFECT OF SOLVENT ON THE COPOLYMERIZATION OF 2,2,6,6-TETRAMETHYL 4-PIPERIDINYL METHACRYLATE WITH STYRENE

The radical copolymerizations of 2,2,6, 6-tetramethyl 4-piperidinyl methacrylate (TMPM) with styrene in various solvents have been studied. The monomer reactivity ratios r_1 and r_2 were determined. It is observed that in all of these reaction systems, there are appreciable solvent effects on both r_1 and r_2, which can be correlated to the difference in chemical shifts of olefinic protons of TMPM. And the variance of the copolymer microstructure in various media was discussed.     

COPOLYMERIZATION AND DETERMINATION OF MONOMER REACTIVITY RATIOS OF DL-LACTIDE WITH 3-BENZYLOXYMETHYL-1,4-DIOXANE-2,5-DIONE

The copolymerization of DL-LA and 3-BMG was carried out in bulk with Stannous 2-ethylhexanoate as thecatalyst. A series of copolymers with pendant protected groups were obtained and characterized by ~1H-NMR and GPCanalysis. The monomer reactivity ratios were evaluated by the Fineman-Ross method and the Kelen-Tudos method and foundto be r_(BMG) = 1.96 and r_(LA) = 0.37, respectively.     

AM1 METHOD STUDY ON THE REACTION OF OZONE WITH ETHYLENE

ＡＭ１ＭＥＴＨＯＤＳＴＵＤＹＯＮＴＨＥＲＥＡＣＴＩＯＮＯＦＯＺＯＮＥＷＩＴＨＥＴＨＹＬＥＮＥ￥ＳａｎＧｕｏＨＯＮＧ；ＳｈｅｎＷＡＮＧ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＪｉａｎｇｘｉＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｎａｎｃｈａｎｇ３３００...     

A REGRESSION STUDY ON THE INCLUSION OF CYCLODEXTRIN WITH BENZENE DERIVATIVES

Ａ　ＲＥＧＲＥＳＳＩＯＮ　ＳＴＵＤＹ　ＯＮ　ＴＨＥ　ＩＮＣＬＵＳＩＯＮ　ＯＦ　ＣＹＣＬＯＤＥＸＴＲＩＮ　ＷＩＴＨ　ＢＥＮＺＥＮＥ　ＤＥＲＩＶＡＴＩＶＥＳＡＲＥＧＲＥＳＳＩＯＮＳＴＵＤＹＯＮＴＨＥＩＮＣＬＵＳＩＯＮＯＦＣＹＣＬＯＤＥＸＴＲＩＮＷＩＴＨＢ...     

AB INITIO STUDY ON THE REACTION OF CH WITH NH3

ＡＢＩＮＩＴＩＯＳＴＵＤＹＯＮＴＨＥＲＥＡＣＴＩＯＮＯＦＣＨＷＩＴＨＮＨ３￥ＺｈｉＸｉａｎｇＷＡＮＧ；ＲｕｏＺｈｕａｎｇＬＩＵ；ＭｉｎｇＢａｏＨＵＡＮＧ；ＺｈｏｎｇＨｕａＹＵ（Ｄｅｐａｒｔｍｅｎｔｏｆｃｈｅｍｉｓｔｉｙ，ＢｅｉｊｉｎｇＮｏｒｍａｌＵｎ...     

AB INITIO STUDY ON GAS-PHASE FACTION OF Ca WITH HN_3

ＡＢＩＮＩＴＩＯＳＴＵＤＹＯＮＧＡＳ－ＰＨＡＳＥＦＡＣＴＩＯＮＯＦＣａＷＩＴＨ　ＨＮ_３（ＲｏｎｇＳｈｕｎＺＨＵ；ＳｈｕＳｈａｎＤＡＩ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＹｕｎｎａｎＵｎｉｖｅｒｓｉｔｙ．Ｋｕｎｍｉｎｇ６５００９１．）ＡＢＩ?..     

GRAFT COPOLYMERIZATION OF DENTAL COLLAGEN WITH METHYL METHACRYLATE

The graft copolymerization of MMA onto human dentin was studied with the redox system usingK_2S_2O_8+NaHSO_3 as initiator. The IR spectrum of the copolymer showed the presence of C=Oband at 1720 cm~(-1),C--O at 1260~(-1), CH_3, at 2850 cm~(-1). indicating the presence of polymerized me-thacrylate on the detin. The ppt. of the acid hydrolysis of the graft copolymer showed an -NH_3~+band of amino acid at 3200 cm~(-1). Most marked percent decreases in contents of amino acids inthe acid hydrolysate were observed in serine, tyrosine and methionine. The absolute amounts ofglycine, alanine and proline have also decreased markedly. This suggests that it was most proba-ble that the graft copolymerization occurred at these residues. The tubular stripes and cross sectioncavities of dentin tublets were covered with a high polymer graft which could be seen from the SEMpictures. The mol. wt. of this grafted high polymer, as determined by GPC, was higher than thatof the homopolymer and the former had a broader mol. wt. distribution. All these facts suggest-ed that a genuine graft copolymerization of MMA onto human dentin occurred.     

STUDY ON HYDROLYSIS OF MACROMOLECULAR GELATIN WITH ENZYMES IN COMBINATION MODE

INTRODUCTIONMacromolecular gelatin is principally derived from type collagen. Gelatin hydrolyzate can be prepared frommacromolecular gelatin by hydrolytic reaction with acid, alkali, heating or enzyme.The gelatin hydrolyzate maintains most of the inherent physical and chemical characteristics ofmacromolecular gelatin and also acquires some new ones by taking advantage of the lowering of the molecularweight. With the advancement of science and technology, the application of gelatin hydroly…     

STUDY ON PYROLYSIS OF POLYPHENYLSILSESQUIOXANE

X-ray photoelectron spectroscopy and Raman spectroscopy were used to determine the chemical change ofpolyphenylsilsesquioxane (PPSQ) during pyrolysis in flowing nitrogen. Two temperature ranges were found for pyrolysedPPSQ below and above 600℃, respectively. The former is related to the rearrangement of PPSQ backbone and the latterreflects that most of backbone structure of PPSQ might be broken down and unorganized. Carbon formed in carbonization ofPPSQ sample pyrolysed at 900℃ should be sp~3 bonded carbon with crystallite size effects or defects.     

STUDY ON STRUCTURE AND BOND CHARACTER OF SAMARIUM COMPLEX WITH β-ALANINE

The structure and properties of Sm complex with β-alanine have been studied by quantum chemical calculation, The theoretical result agree well with the experimental ones obtained in studies on rare earth complexes with amino acids.     

STUDY ON SYNTHESIS OF HIGH VINYL POLYBUTADIENE WITH TETRAVALENT MOLYBDENUM CATALYST SYSTEM

In this paper the catalytic behaviour of tetravalent molybdenum catalyst system in polymeriza-tion of butadiene is dealt with. The effects of the variety of apions combined with molybdenumatom, the pattern of the substituent R in (i-Bu)_2AlOR and the polymerization conditions on thebutadiene conversion, the molecular weight and its distribution and the microstructure of the polymeralso are studied. It has been found that the catalyst system is significantly active when anions com-bined with the molybdenum atom are acetoxy (CH_3COO-),or ethoxy (C_2H_5O-). Obviously, thevariety of substituent R in (i-Bu)_2 AlOR has a great influence on the catalytic activity. The catalystsystem is inactive if the R group is--COR' (R'is alkyl or aromatic group) or alkyl, whereas the activityof the catalyst system increases if the R group is phenyl or tolyl. With the rise of polymerizationtemperature the polymer molecular weight decreases, the distribution index of molecular weight in-creases and the content of 1,2-unit in polybutadiene reduces.     

STUDY ON THE TREATMENT OF3-PHENOXY-BENZALDEHYDE INDUSTRIAL WASTEWATER WITH POLYMERIC ADSORBENT

1.INTRODUCTIONResinadsorption(RA)iswidelyusedinthetreatmentofwastewatercolltainingorganiccontaminantsll--5].Theprocessincludesadsorptionanddesorption.WhenaflowofwastCwaterisdeliveredtoanadsorptionresinbed(oftenfixedbed,foritsconveniencetooperate),thedrainwateriscleanedandtheimpuritiesareabsorbed.Theusedresinisdesorpedorregeneratedbyusingaregenerant.Theorganiccompoundsabsorbedintheresinarethenextraaedbytheregenerant16'71.Insomecases,theorganiccompoundintheregenerantsolutionisvaluableandw…     

A STUDY ON THE SELECTIVE REDUCTION OF AROMATIC AMIDE WITH LiAlH_4

In the synthesis of l-phenyl-5-substituted amino-4-pyrazole N-alkyl amide,it was found for the first time that one of the two aromatic amido groups in the moleculeof 1-phenyl-5-benzoyl amino-4-pyrazole N-alkyl amide was reduced selectively by LiAlH_4.new conclusion was drawn after several experiments have been done that ortho-amino(orsubstituted amino)aryl amide or the aryl amide with its ortho substituent which canbe reduced into an amino group(or substituted amino group)can not be reduced by LiAlH_4.It was further rationalized by quantum chemical calculation.