SYNTHESIS AND PROPERTIES OF NEW INTERPOLYMERIC COMPLEXES

β-(2-imidazolinyl)-ethyl methyl diethoxy silane quarternary halides and its condensed polymers with bisphenol A were synthesized and characterized. The polycation-polyanion complexes were prepared by the condensed polymers and poly (styrene sulfonate). The solubility and thermal stability of interpolymeric complexes were investigated.     

SYNTHESIS AND THERMAL PROPERTIES OF A NEW CHOLIC ACIDCONTAINING COPOLYMER

A new copolymer was synthesized by free radical polymerization in solution from methyl 3α-methylacryloyl-7α, 12α-dihydroxy-5β-cholan-24-oate (MACAME) and maleic anhydride (MAN). The copolymer was characterized by FT-IR and functional group analysis. The reactivity ratios of the two monomers were estimated [r_1 = 11.6 (MACAME), r_2 = 0.01(MAN)] by conducting a series of copolymerizations with a variety of monomer feed compositions and analyzing thecopolymer composition. Thermogravimetric and differential scanning calorimetric analyses of the samples indicate that thecopolymer possesses good thermal stability. The temperature at which the copolymer samples experienced a 10% weight loss(T_(WL)) is over 287℃, and the T_g ranged from 174 to 185℃ for the copolymers.     

EFFECT OF CHEMICAL STRUCTURE OF COMONOMERS ON THE PROPERTIES OF COPOLYESTERS

The effect of different kinds of comonomers with or without flexible chain on proper-ties of copolyesters, such as transition temperature, crystallization velocity, crystallinityand size of crystallites, is studied. The experimental results indicate the obvious differ-ence in properties between comonomers with iso- and ortho-structure of phenyl ring andcomonomers with flexible chain. The influence of chemical structure of comonomers onproperties of copolyesters is discussed.     

THE CORRELATION BETWEEN ~(13)C CHEMICAL SHIFTS OF DNA AND INTERSTRAND PURINE-PURINE CLASH

The correlation between ~(13)C chemical shifts of DNA and structure parameters (the mainaxis helix twist angle Ω, base--plane roll angle ρ, main chain torsion angle δ and pro-peller twist angle ω) has been discovered and proved indirectly. The carbons relating tothe structure parameters have been found and interpreted theoretically. Relative variationsin chemical shifts of these carbons obviously reflect purine-purine clash (steric hindrance)and have been compared with sum functions Σ of Calladine--Dickerson rules. It would bepossible to provide the information about conformation of DNA from ~(13)C NMR spectra andto observe the structure parameters of Ω,ρ,δ and ω of DNA in solution.     

STUDY ON THE CHEMICAL CONSTITUENTS OF BIDENS BIPINNATA A NEW POLYACETYLENE GLYCOSIDE

A new naturally occurring compound 1-polyacetylene glycoside has been isolated form the n- butanol soluble fraction of the leaves of Bidens bipinnata. The chemical structure of 1 was shown to be 3E, 11E—Diethenylene 5. 7. 9—triacetylene, 1, 13—tridecanglycol-2-O-β-D-glycoside named bipinnatpolyacetyloside according to spectral analyses of UV. IR. FDMS, ~1H-NMR, ~H-~H COSY, ~(13)C-NMR and DEPT.     

DYNAMIC MONTE CARLO STUDY ON THE CORRELATION BETWEEN SHAPE AND SIZE OF LINEAR POLYMER CHAINS

The correlation between shape and size of linear chains on the simple cubic lattice is investigated using a dynamicMonte Carlo technique. A positive correlation between the asphericity parameter A and the square of the end-to-end distanceR~2, as well as that between A and the square of the radius of gyration S~2, is found for both RW and SAW chains, indicatingthat a chain conformation of small size is usually more spherical than one of large size. The result can explain why the shapeof the SAW chain deviate much more from a sphere than that of the RW chain, and can also explain the similar dependenceof size and shape on chain stiffness and on the distance of the first bead of a chain from an infinitely large flat surface.     

SYNTHESIS AND PROPERTIES OF A NEW AZOBENZENE SIDE-CHAIN POLYMER CONTAINING A TEMPO RADICAL

To allow anisotropies of optical properties in a magnetic field, nitroxide radical is introduced into the ortho-position of the phenylene ring in the side chain. A new azobenzene side-chain polymer (TEMPO-PAZ) containing TEMPOradical was synthesized. The polymer has a good solubility in organic solvents. The ESR spectrum of the polymer indicatedthree absorption lines characteristic of TEMPO radical. The optical phase conjugated responses (I_4) of the polymer filmswere investigated by degenerate four-wave mixing (DFWM). The experimental results showed that optical phase conjugatedresponse of the TEMPO-PAZ could be easily controlled by choosing the appropriate direction of magnetic field presumablydue to the nitroxide radical in the TEMPO-PAZ molecular structure. For the polymer investigated here, the nitroxide radicalwas introduced to increase optical phase conjugated response intensity in a magnetic field, aiming originally at searching fora new photo-active organic magnetic multifunctional materials.     

ISOLATION, PROPERTIES AND CHEMICAL STRUCTURE OF A GLUCAN FROM GLYCYRRHIZIA URALENSIS FISCH

A new polysaccharide,GBW was obtained homogeneous as determined by HPLC from the roots of Glycyrrhizia uralensis Fisch. The molecular weight was estimated to be 4000. The component sugar was identified as glucose only. The specific rotation [α]~(28)_D (C=0.1,H_2O) was +1200. The α-configuration was established by IR and ~(13)C NMR. Methylation analysis, periodate oxidation, Smith degradation, partial hydrolysis, KI-I_2 reaction and ~(13)C NMR showed that GBW is a new (1→4)linked linear α-D-glucan. The structure is shown as 1.     

THE RELATION BETWEEN MOLECULAR MOTION AND ION CONDUCTIVITY ON A NEW COMBLIKE POLYMER

ＴＨＥＲＥＬＡＴＩＯＮＢＥＴＷＥＥＮＭＯＬＥＣＵＬＡＲＭＯＴＩＯＮＡＮＤＩＯＮＣＯＮＤＵＣＴＩＶＩＴＹＯＮＡＮＥＷＣＯＭＢＬＩＫＥＰＯＬＹＭＥＲ￥ＬｉＱＩ；ＹｕｎＱｉｎｇＬＩＮ；ＦｏＳｏｎｇＷＡＮＧ（ＣｈａｎｇｃｈｕｎＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉ...     

CORRELATION BETWEEN GLASS TRANSITION OF POLYMERS AND ENERGY OF ROTATIONAL ISOMERIZATION OF MOLECULAR CHAINS

It has been shown that the free volume fraction at T_g is not a universal parameter for linear polymers of different molecular structure. The reason is that the volume expansion at T_g is partially contributed from the change of the numbers of conformations of isolated molecular chains due to internal rotation. In this paper, glassy transformation was connected with internal rotation of isolated molecular chains, and the relationship between free volume fraction of polymers at T_g and energy e of rotational isomerization of isolated molecular chains was formulated, e=-k·T_g·In (△α·T_g/1-△α. T_g). The values of calculated from the above formula are in good agreement with those published in the literatures. Thus, the method described in this paper can be used to estimate a parameter for the flexibility of isolated molecular chains.7     

A STUDY ON THE MORPHOLOGY AND PROPERTIES OF IPP/IIR BLENDS

The effect of isobutylene-isoprene rubber (IIR) on the crystallizing behavior of isotactic polypropylene (IPP) as well as the morphology of the blends in relation with its properties have been studied by DSC, WAXD, polarized light microscope, SEM and mechanical properties test. The experimental results show that IIR has slight influence on melting point, crystallinity, crystallization rate of IPP. It seems certain that IIR has not entered into IPP phase in melt state. IIR has retarding action on the growth of IPP crystal and is an effective nucleating agent of IPP spherulites. The impact strength of the blend increases rapidly with IIR content more than 30 parts; the tensile strength of the blend, however, decreases as IIR content increases. The temperature and time of alter heat-treatment also have great influence on the impact strength of the blend. The impact strength of IPP/IIR (100/20) heat-treated at about 130℃for 2h is 5 times as high as that of the untreated blend.     

STUDIES OF THE INTERACTION BETWEEN METALLOPORPHYRINS OF TMPYP－3 AND SINGLE－STRANDED DNA ON NC MEMBRANE

ＳＴＵＤＩＥＳＯＦＴＨＥＩＮＴＥＲＡＣＴＩＯＮＢＥＴＷＥＥＮＭＥＴＡＬＬＯＰＯＲＰＨＹＲＩＮＳＯＦＴＭＰＹＰ－３ＡＮＤＳＩＮＧＬＥ－ＳＴＲＡＮＤＥＤＤＮＡＯＮＮＣＭＥＭＢＲＡＮＥ￥ＹｏｎｇＣＨＥＮ；ＹｕａｎＺｏｎｇＬＩ；ＷｅｎＢａｏＣＨＡＮＧａｎｄＹ...     

QUANTUM CHEMICAL STUDY ON THE THERMOLYSES OF 1，5－CYCLOOCTADIENE AND 4－VINYLCYCLOHEXENE

ＱＵＡＮＴＵＭ ＣＨＥＭＩＣＡＬ ＳＴＵＤＹ ＯＮ ＴＨＥ ＴＨＥＲＭＯＬＹＳＥＳ ＯＦ １，５－ＣＹＣＬＯＯＣＴＡＤＩＥＮＥ ＡＮＤ ４－ＶＩＮＹＬＣＹＣＬＯＨＥＸＥＮＥ￥ＳａｎＧｕｏ；ＨＯＮＧＳｈｅｎＷＡＮＧ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓ...     

A NEW PROBE FOR IDENTIFYING PROPERTIES OF SUPPORTED METAL AND METAL OXIDE CATALYSTS

A novel molecular probe for identifying properties of supported transitionmetals and metal oxides catalysts was established.The catalytic mechanism oftransition metals was proposed.     

TETRAHYDROPROTOBERBERINE—A NEW CHEMICAL TYPE OF ANTAGONIST OF DOPAMINE RECEPTORS

In rats lesioned by unilateral micro-injection of 6-OHDA into substantia nigra, the apomorphine-induced contralateral rotation and the amphetamine-induced ipsilateral rotation were antagonized by THB, l-THP and haloperidol. Scopolamine reversed the antagonistic effect of THB against amphetamine. Thus, THB and 1-THP exhibited the DA-receptor antagonistic property which was similar to that of haloperidol.l-SPD (10mg/kg), however, only antagonized the amphetamine-challenged rotational response, while it could not antagonize, but potentiate, the apomorphine-challenged rotational response. So, l-SPD might be a partial agonistie antagonist of DA-receptors, and its effect was more potent than that of THB and l-THP. l-SPD would be ascertained further in clinic trial.From these results and others, the authors suggest that THPB is a new chemical type of antagonist of brain DA-receptors.     

INFLUENCE OF COMPOSITIONAL HETEROGENEITY ON MORPHOLOGY AND PROPERTIES OF SEGMENTED COPOLYMERS

Polyethylene terephthalate(PET)/polycaprolactone(PCL) segmented copolymers with different hard segment contents and a blend of two of them were studied by using DSC, WAXS, TEM and IR techniques and dynamic mechanical, stress-strain and isothermal crystallization measurements. Emphasis was laid on the studies of influence of compositional heterogeneity on the morphology and properties of these segmented copolymers. It was found that the solution cast specimens of the more heterogeneous sample exhibit better segregation of segments, high crystallinity and melting temperature. They have higher thermal stability of mechanical properties at small deformations. However, they are less stable against large deformations and may become softer than the more homogeneous ones.     

STUDIES ON SYNTHESIS AND PROPERTIES OF BIS（β－ALKOXYCARBONYALKYL）TIN POLYTHIOETHERS

ＳＴＵＤＩＥＳＯＮＳＹＮＴＨＥＳＩＳＡＮＤＰＲＯＰＥＲＴＩＥＳＯＦＢＩＳ（β－ＡＬＫＯＸＹＣＡＲＢＯＮＹＡＬＫＹＬ）ＴＩＮＰＯＬＹＴＨＩＯＥＴＨＥＲＳＣｈｅＲｏｎｇｒｕｉ（ＩｎｓｔｉｔｕｔｅｏｆｔｈｅＰｏｌｙｍｅｒＣｈｅｍｉｓｔｒｙ，ＮａｎｋａｉＵｎ...     

STUDY OF THE CORRELATION BETWEEN THE STRUCTURE OF THE [Ir(сod)Cp] COMPLEX AND ITS THERMAL PROPERTIES

Journal of Structural Chemistry - A volatile iridium(I) complex [Ir(cod)Cp] (cod - 1,5-cyclooctadiene, Cp - cyclopentadienyl) is synthesized and characterized by IR and NMR spectroscopy. The...     

THE EFFECTS OF CHEMICAL AND PHYSICAL FACTORS ON BIOCATALYTIC TRANSFORMATION OF STEROID

Ｃｈｅｍｉｃａｌｓｙｎｔｈｅｓｉｓｐｌａｙｓａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｃｕｒｅｎｔｍａｎｕｆａｃｔｕｒｅｏｆｐｈａｒｍａｃｅｕｔｉｃａｌｓｔｅｒｏｉｄｈｏｒｍｏｎｅｓ．Ｂｕｔｓｏｍｅｏｆｔｈｅｉｍｐｏｒｔａｎｔｓｔｅｐｓ，ｓｕｃｈａｓｈｙｄ...