最新刊期
卷 ， 期 1 ， 1992
- 摘要：Through reaction between the hydroxy groups of poly(vinyl alcohol) (PVA) and acetone, various polyvinyl ketal copolymers (PVKT) containing 13C-NMR spectroscopy at 22.5 MHz. Ketal rings in partly ketaled PVA were assigned into MM-cis, MR-cis and RR-trans types, and corresponding equilibrium constants Kmm, Kmr, Krr, and rate of ketalization reaction were discussed.
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发布时间：2021-03-19 - 摘要：The properties of fractionated polyacrylamide(PAAM, Mw 104-107) in dilute aqueous salt solutions were studied by light scattering and viscometric methods. The relationships among intrinsic viscosity, mean square redius of gyration )z, the second virial coefficient A2 and weight average molecular weight were observed respectively. Additional results PAAM in 0.2 mol/1 NaCl aqueous solution were also obtained from a excluded volume exponent v = 0.566 A2: The ratio of the mean square end to end distance to 2>2 equals 6.68 and the interaction parameter between macromolecules and solvents is 0.489.
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发布时间：2021-03-19 - 摘要：Three series MC nylons were prepared by changing the amount of catalysts. Their spheru-Llitic morphologies and some properties were characterized. The amount of the initiator and the activator greatly affects the polymerization rate, the conversion rate of caprolactam and the melt flow rate of MC nylon. In order to obtain MC nplon possessing excellent properties, the amount of catlysts must be limited in the fixed range. The lowering of the amount of the activator is an effective route to improve the impact srength of MC nylon.
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发布时间：2021-03-19 - 摘要：The effect of micelle on nucleation in the crystallization process of dilute poly(ethylene-b-styrene-b-ethylene) triblock copolymer/ethylene homopolymer solution has been studied. Theresults show that micelles composed of the copolymer act as nucleator, which provides a new way to improve the properties of semicrystalline homopolyer.
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发布时间：2021-03-19 - 摘要：In present paper, the properties of charge-mosaic membrane prepared from irradiated poly(styrene-butadiene-4-vinylpyridine) triblock copolymer were investigated. The results showed that the fluxes of water and electrolyte through the membrane are 2.40×10-5 mol/cm-3 min, and 2.10×10-3 mol/cm-2 sec respectively when the concentrations of KCl are 0.1 mol/1 and 10-3 mol/1 on the two sides of membrane. Experimental results of separation showed that charge-mosaic membrane has better dialysis properties for permeation to salt but not to high mole-cular weight or low molecular weight non-electrolytes.For mixed solution of KCl and protein,KCl and sucrose,the fluxes of KCl are 1.07×10-8 mol/cm2sec and 1.10×10-8 mol/cm2sec respectively.
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发布时间：2021-03-19 - 摘要：Esters products were synthesised through the reactions of chloroacetyl chloride with ethy-lene glycol, diethylene glycol, triethylene glycoJ and six polyethylene glycols with different average molecular weights, respectively. Index of refraction, density and surface tension of liquid products were measured and structures of the products were characterized with IR and 1H-NMR spectroscopies. For the reaction between chloroacetyl chloride and polyethylene glycol (Mn= 400), influences of reaction conditions suchas feed ratio,temperature,time and environ-ment have been investigated.
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发布时间：2021-03-19 - 摘要：The crystalline structures of the hot-melting adhesive fibers of two series of copolyesters have been studied by wide angle X-ray diffractive technique. Their melting behavior has been investigated by Differential Scanning Calorimetry(DSC). The mechanism of the lowest melting behavior in the series was revealed. The experiments indicated that in most cases, the crystallization in fibers was carried out from one type of the structural repeat units in fibers.The fibrous samples in each series can be divided into two parts according to the lowest melting temperature. The melting point fusion heat and crystallinity of the fibrous samples in each part changed regularly with varying mol% of 1,6-haxane diol to 1,4-butane diol in the ini-tial monomer feed. The mechanical properties of fibers were related to their crystallinity. While the not-melt adhesive performance was dependent on the non-crystalline region in the fibers.The adhesive effect was improved greatly with increasing the content of flexible component in non-crystalline region in the fibers.
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发布时间：2021-03-19 - 摘要：Segmented polyether poly(urethane-ester) (PEUE) based on poly(tetramethylene oxide) (PTMO) Mω 1000, methylene-diphenyl-diisocyanate (MDI) and bis-hydroxpethyl-terephthalate (BHET) or its dimer (BHET-D) were synthesized, and their morphology and properties were characterized using FT-IR, dynamic mechanical analysis, differential scanning calorimetry (DSC) and tensile measurements.The results indicated that the microphase separated (PEUE) had higher mechanical strength and longer rubber plateau temperature range than those in conventional polyether polyure-thanes. Increasing hard segment content or length led to increasing tensile strength and pla-teau modulus,and decreasing the degree of phase separation between the hard and soft seg-ments. These features were considered due to the hard segments composed of high crystallizable,rigid aromatic esters while introducing ester groups in hard segments also enhanced compacti-bility with polyethe soft segments.
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发布时间：2021-03-19 - 摘要：GPC and intrinsic viscosity measurements of vinylidene chloride-methyl acrylate (wt. ratio 90:10) copolymer in tetrahydrofuran at 30℃ were done. Based on the principle of GPC universal calibration, a new precise and simple method was developed for determining the Mark-Houwink constants of the system. In this method, the experimental data of GPC and [η] from several samples, rather than two samples, were adopted for improving the reliability of the approach. The values of K=3.421×10 and a = 0.64 were obtained.
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发布时间：2021-03-19 - 摘要：Epitaxial crystallization of highly oriented films of LLDPE/IPP blends has been studied in this work by means of trsamission electron microscopy. The melt-drawn films of pure LLDPE or IPP consist of highly oriented lamellar structure. The growth direction of LLDPE and IPP lamellae is perpendicular to the drawing direction. When the content of LLDPE in the LLDPE/IPP blends is below 40%, epitaxial growth of LLDPE lamellae on highly oriented IPP lamellae has been observed. The intercrossing angle of the two kinds of epitaxial lamellae is about ±45℃,while the contact planes should be (010) of IPP and (100) of LLDPE.There is noabove relationship of epitaxial crystallization in the films when the content of LLDPE in the blends is over 50% because of the formation of independent domain of LLDPE.When the films of LLDPE/IPP blends was heat-treated at 135℃(above the melting point of LLDPE) for 15 min,and subsequetly cooled to room temperature,the epitaxial relationship between LLDPE and IPP is maintained.
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发布时间：2021-03-19 - 摘要：In this paper results concerning emulsion copolymerization of vinyl acetate (VA) and butyl acrylate(BA) are presented. The mechanisms of particle nucleation and growth are studied by measuring perticle size and particle number in different monomer ratio copolymerization. The results show that increasing VA content in comonomer mixture causes a larger particle number and smaller particle size. The dependences of particle size and particle number as well as particle morphology upon monomer conversion are also discussed.
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发布时间：2021-03-19 - 摘要：The phase transition kinetics of temperature-sensitive N-isopropylacrylamide hydrogel was investigated. It was indicated that the apparent second order kinetic equations describe its swelling and collapse behavior quite well. Its swelling kineticequation is (dR)/(dt)= ks(Rg- R)2 and the collapse one is- (dR)/(dt)= (kc(R-Rc)2. A para-meter of "reasonable time of separating circle per swelling ratio" was introduced for describing the separating behavior of polymer water solution. It can be calculated from initial swelling ratio,equilibrium swelling ratio,swelling kinetic constant and collapse kinetic constant. The equation is At the ideal case,total time for separation is proportional to The ratio factor is equal to the total water weight separated divided by the dry hydrogel weight,that is When the calculated value of the total time based on the two ki-netic equations was located into the region of it means that the dry hydrogel weight chosen and the circular swelling ratio region chosen are reasonable.
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发布时间：2021-03-19 - 摘要：As a part of the studies on functional silicone, the monomers, Y (CH2)nSiX3.were synthesized by means of hydrosilylation reaction of corresponding vinyl monomers. Details of the synthe-sis are descr1bed. IR and 1H-NMR,from which the chemical structure of the monomers and the direction of the hydrosilylation reaction were determined,are shown.Moreover,TGA results of the polymers formed by hydrolytic polycondensation of the monomers are also given. According to the TGA resuts the decomposition temperature of these polymers are all above 250℃ and the polymers with aryl group at β-carbon atom have a higher decomposition temperature than those polymers with aryl group at γ or δ position.
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发布时间：2021-03-19
Research Article
- 摘要：The transparency of nylon 6 filaments is changed by spherulites formed by Solvent Induced Crystallization (SINC) in quenching bath. The long carbon chains in alkyl diamides additives can prevent Solvent (water) Induced Crystallization so that the transparency of nylon 6 filaments is improved. The nylon 6 filaments were examined by Scanning Electron Microscopy (SEM), Small-Angle Light-Scatting (SALS), polarized microscope, light transmission rate, contact angles and others.
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发布时间：2021-03-19 - 摘要：High optically active, isotactic poly (trityl methacrylate) is examined by 13C-NMR in solution and in solid-state. The spectra were assigned by using DEPT sequence. It was shown that more bulk hinded PTrMA adopts similar chemical shift, chain comformation either in solution or in solid state. 13C-CP/MAS NMR spectra provided more information for studies on the structure of insoluble polymer. The most significant difference are observed for -CH2- peaks by comparing 13C solid NMR spectra between the recemic and optically active PTrMA.
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发布时间：2021-03-19 - 摘要：PET pellets were dissolved in chloroform-trifluoroacetic acid (4.1 vol.). The concentrations of solution were 9 and 12 wt% respectively. A glass plate was inserted into the solution, then taken out and held at different temperature (from room temperature to 100℃) to make the solution cast films of ca. 10μm thick. The absorbance ratio A978/A795 of 973cm-1 and 795cm-1 infrared bands was used to measure the crystallinity of the solution cast PET films. The result shows that the film cast at room temperature was amorphous.
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发布时间：2021-03-19 - 摘要：In this paper, the graft copolymerization of methyl methacrylate onto starch using acety-lacetonate copper (II) uomplex as initiator was studied. The percentage and efficiency of grafting were investigated by varping the concentrations of initiator, monomer and starch, various acids, trichloroacetic acid, and the reaction temperature. By varying these reaction parameters, the percentage and efficiency of grafting could be adjusted effectively.
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发布时间：2021-03-19 - 摘要：The mechanical property and microscopic morophology of self-reinforced HDPE were investigated. The tensile strength and modulus of self-reinforced HDPE, compared with those of normal HDPE, were enhanced appreciably. The morphological structure was changed as a result of self-reinforcement. The shish-kebab and the fibrous structure in self-reinforced HDPE were given credit for its excellent property.
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发布时间：2021-03-19 - 摘要：p-Chloromethylstyrene (p-CMS) is a useful monomer for the preparation of functional polymers. Radical copolymerization of this compound with acrylonitrile( AN), ethyl methacry late (EMA) and butyl methacrylate (BMA) were studied at 60℃. The compositions of the copolymers were determined by the elementary analysis of chlorine. The monomer reactivity ratios (r1 and r2) were obtained by the Fineman-Ross method. The Q,e values of p-CMS were calculated by the Q-e scheme of Alfrey and Price.
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发布时间：2021-03-19 - 摘要：A kind of high trans-1,4-polyisoprene (TPI) was synthesized by coordinative polymerization of isoprene with supported titanium catalyst and triisobutylaluminium. The experimental results illustrated that the catalytic efficiency (CE) increases when the monomer concentration, polymerization temperature and time are increased. Under suitable conditions the CE can-exceed 2000 gTPI/gTi and the inherent viscocity of the TPI is about 4-6dl/g. The micro-structure of the synthesized TPI was characterized by IR and 13C-NMR spectra It was verifi-ed that the microstructure of the TPI is nearly all trans-1,4 chain unit(above 99%).Its melt-ing temperature is about 60℃ by DSC method.
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发布时间：2021-03-19 - 摘要：The polymerization of acrylamide was carried out in H2O-DMF (3:1 v/v) solution using eerie ion (eerie ammonium nitrate, CAN) as initiator. It was found that the presence of 4,4'-diacetaminodiphenylmethane (DAADPM) could promote the polymerization and increase the rate of polymerization. The overall activation energy and rate equation of acrylamide polymerization initiated with eerie ion/DAADPM system were determined respectively. From IR spectrum end-group analysis of polyacrylonitrile (PAN) prepared by solution polymerization of AN using CAN/DAADPM system as initiator,it revealed the presence of DAADPM end-group in the polymer. Accordingly,the initiation step includes the addition of DAADPM radical to monomer and forms the end-group of polymers.
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发布时间：2021-03-19
Research Bulletin
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