最新刊期
卷 ， 期 1 ， 1984
- 摘要：The PAN fiber treated by Lewis acids (e.g. stannic chloride) could be transformed into a macromolecular conducting fiber by further heat treatment. The resistance of the fiber varied from 103 to 1012Ω.cm owing to different thermal treatment, and kept stable after hydrolysis. The fiber had enough strength to be processed by using various means. This is a new kind of macromolecular conducting fibers having some analogies to the characteristics of organic semiconductors.
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发布时间：2021-03-19 - 摘要：Ethylene oxide was polymerized in toluene with bimetallic-loxo-alkoxide catalyst or i-Bu3Al-H3PO4H2O-dimethylaniline (DMA)quatermary catalyst, polymerization proceeded homogeneously. Both catalysts show high activity. The molecular weight of the products obtained approaches one million. If petroleum ether was used instead of toluene as polymerization medium, both conversion and molecular weight of the polymer decreased. The optimum molar ratio of i-Bu3Al:H3PO4:H2O:DMA eqaual 1:0.17:0.17:0.10. The product ob-tained with these catalyst dissolves in water and can be molded.The breaking strength increases with increase in molecular weight and can reach 100kg/cm2.
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发布时间：2021-03-19 - 摘要：By reacting dipotassium salt of 5-fluorouracil with bis-( a -chloroacetoxy) polymethy-lenes, six new polyesters containing 5-fluorouracil in the main chain were prepared. The anti-tumor activity of some of these polymers were tested on mice against Sarcoma 180. Three new bis-( a -chloroacetoxy) polymethylene monomers were also prepared and characterized.
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发布时间：2021-03-19 - 摘要：In our previous report, it was discovered that the polycondensation reaction of 9-amino-pelargonic acid followed second order kinetics from the beginning up to an extent of reaction, p, about 99%, after that, the system became very viscous, the reaction changes rapidly to a third order kinetics In this paper, we wish to report that, this change of the reaction order from second to third occured also in the polycondensation of 6-amino-caproic acid and 11-amino-undecanoic acid. The transition regions lie again at p about 99%.From these results,it may conclude that this is a general rule in the polyamidation of the w-amino-acid (monomers of the AB type),and the contradictory results appeared in literature in this fi-eld may be settled by our experiment.
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发布时间：2021-03-19 - 摘要：The polysiloxanes containing 5-fluorouracil were prepared by reacting diethylaminopoly-disubstituted siloxanes with 5-fluorouracil. The obtained polymers were structural characterized by IR and H-NMR spectra. The products were hydrolyzed in acidic, alkaline and neutral medium at room temperature respectively. The amount of 5-fluorouracil released was quantitated by measuring its UV absorbance at 266.5 nm. However in the case of polymers containing dimethylsiloxy ((CH3)2SiO-) moiety, their stabilities toward hydrolysis are inc reased as the value n increases. Polymers with Si-N- linkage (type A) hydrolyze more rapidly in acidic medium but slowly in alkaline medium than the polymers with Si-O-linkage (type B).
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发布时间：2021-03-19 - 摘要：9-Amino-pelargonic acid was synthesized from sebacic acid through mono-esterification, ammonolysis and Hofmann's degradation. The monomer was polycondensed both in 15 g and in 4 kg scale, by heating at 260℃ for 3-4 hours. The molecular weight of the polymer attained 20000-26000. The polymer was spun into nylon-g fiber at 288℃ and drawn at 120℃ to 4.5 times its length. The structure and the properties of the polymer and the fiber were determined by various methods, which included X-ray diffraction, IR, NMR, dynamic viscoelastioc,DTA,TG, viscous flow,etc. The outstanding features of the nylon-g fiber are its wearbility,double flexural times.
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发布时间：2021-03-19 - 摘要：Sodium sulfohexyl methacrylate (SSHMA) was copolymerized with methyl methacry-late (MMA)，hydroxyethyl methacrylate (HEMA) and n-hexyl methacrylate (HMA)．The reactivity ratios of various monomers with SSHMA(M1) were：for MMA，r1=1.12±0.01，r2=0.77±0.01；forHEMA，r1=0.86±0.02，r2=0.93±0.05；forHMA，r1=0.57±0.03， r2=0.59±0.23 (in DMSo)；and for HEMA，r1=0.49±0.01，r2=1.01±0.04 (in wa-ter)．The average values of the copolymerization parameters calculated from the monomer reactivity ratios were Q=1.015 and e=+0.844．The polymerization reaction order of SSHMA with respect to initiator was 0.51 and that with respect to monomer was 1.91 in water soludon，and was 0.53 and 1.91 respectively in DMSO，but the ratio of the rate con-stant KpKt1-2 in water was greater．Tests of heparin-retarded blood coagulation time sho-wed that the anticoagulant activity of poly SSHMA is independent of molecular weight wi-thin the range from 1.3×105 to 10.4×105．
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发布时间：2021-03-19 - 摘要：Polyester as-spun fihers were drawn with a draw ratio ( λ ) of 1.0-4.0 at ambient temperature. Their morphological structures have been studied by means of differential scanning calormetry (DSC) and X-ray diffraction.From DSC measurements, Tm was found to be 530.2 ± 0.4 k and there was a linear relationship between △Hm and λ:△Hm = 39.40 λ 5.05λ(J△g).There was little change of Tc with draw ratio.A broad exothermic region was observed in the zeighborhood of Tg. Its area increases with λ, and its lower temperature limit decreases with λ.The exothermic region is attributed to the crystallization of the oriented moleculat chains in the amorphous samp-les,i.e. the so-called “third phase”.
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发布时间：2021-03-19 - 摘要：By on-line infrared spectroscopic method，the changes of chemical constitution of acy-lonitrile (AN)／diacetone acylamide (DAA)／methyl acylate (MA) copolymers have been measured continuously during its lOW temperature pyrolysis under different atmospheres．From the results it was found that during the pyrolysis dehydrogenation and oxidation re-actions proceeded mainly after cyclization reaction under atmospheric environment，but pro-ceeded before cydization in pure oxygen．In nitrogen atmosphere，only cyclization and dehy-drogenation occurred．It was shown that the length of cycloforming sequence of copolym-ers pyrolyzed in nitrogen before 275℃ was slightly shorter，and after 275℃ was slightly longer than that in other atmosphere．Based on the variation of intensities of characteristic peaks with heating time，it is obvious that the increment of relative content of carbonyl group in the samples is proportional to the square root of pyrolytic time．
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发布时间：2021-03-19 - 摘要：Silica-supported polyvinylpyrrolidone-Pd complex has been prepared and has shown that it can be used as an active catalyst for the hydrogenation of aromatic nitro-compounds at room temperature and atmospheric pressure. The stability of this catalyst during hydrogenation may be increased by adding equimolar acetic acid. The effects of N/Pd molar ratio in the comples, solvents and the kind of substrates used on the catalytic activity were also studied.
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发布时间：2021-03-19 - 摘要：Crystallization and orientation of PET films of different crystallization rates have been studied doing various techniques during stretching. It is found that under the same conditions of stretching the extent of crystallization and degree of orientation are higher within the sample of higher crystallization rateThis difference in structural change implies that it is reasonable to ascribe the difference of the two samples in tensile behavior to their crystallization rates.
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发布时间：2021-03-19 - 摘要：The effects of toolecular weight distribution on the texture formation of as．spun fibe-rs and mechanical properties of polypropylene fibers have been studied．It is shown that the texture formation of as-spun fibers is very sensitive to the presence of high molecalar wei-ght tail in the MWD of polypropylene resin．Under ordinary spinning conditions the as-spun fiber obtained from controHed degraded polypropylene resin showed smectic structu-re with low degree of oritation．However，in the presence of some high molecular weight tail incorproated to the degraded polypropylene resin gave as-spun fibers in a-crystalline modi-fication，although the viscosity average molecular weight and spinning conditions were kept the same．In addition，the birefringence of the as-spun fibers increased sharphy with increa-sing amocnt of the high molecular weight tail in the MWP．The different texture of as-spun fibers resulted in big difference in stretching behavior of the as-spun fiber and mechanical properties of drawn fibers．
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发布时间：2021-03-19
Research Article
- 摘要：A simple and quick method for the determination of the MWD of PPTA at room temperature by GPC is proposed The PPTA sample is dissolved in the mixed solvent (MS), Which is composed of HMPA, DMA and LiCl. DMA+3wt.% Lid is used as an eluent in GPC. The MWD of various kinds of PPTA samples, that were synthesized in different solvent systems and by different polycondensation ways, has been studied. It has been shown that the polydispersity is between the range of 1.8-3.0.
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发布时间：2021-03-19 - 摘要：Bivalent rare earth chlorides——NdCl2-nTHF and SmCl2——have been synthesizedthrough the reduction of corresponding trivalent chlorides with Lithium/Naphthaline in THF. Their catalytic activity for butadiene polymerization was studied. The system composed of NdCl2.nTHF and Et3Al showed a moderate catalystic activity while that composed of SmCl2 and Et3Al was inactive. The difference in activity between NdCl2. nTHF and SmCl2 was discussed.
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发布时间：2021-03-19 - 摘要：In this paper, the radical polymerization of methyl methacrylate (MMA) initiated with benzoyl peroxide (BPO), lauroyl peroxide (LPO), t-butyl hydroperoxide (TBH), t-butyl peroxybenzoate (TBPB) and the effect of amine on the radical polymerization rate were studied, respectively. It was found that the order of polymerization rate Rp was as follows: LPO > BPO > TBH > TBPB. In the presence of tertiary amine such as N, N-di-methyl-p-toluidine (DMT), N-ethyl piperidine (NEP), the amine promoted the polymerizatio of MMA,and the order of Rp changed to BPO-amine>LPO-amine>TBH-amine>TBPB-amine.
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发布时间：2021-03-19
Research Bulletin
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