Advanced Materials Research Vols. 1004-1005

Abstract: The thermal safety of one new-type DB propellant SZQu-1 was studied by ARC. The test results were compared with the one of double-base propellant SF-3. The ARC test results show that, in an ideal adiabatic environment, the initial exothermic temperature for SZQu-1 is 129.0°C, the adiabatic temperature rise is 787.0°C, the maximum self-heating rate is 23329.9°C/min, the maximum pressure rise rate is 51.2×10⁵Pa·min^-1, and the maximum pressure produced by unit mass is 124.1×10⁵Pa·g^-1. The activation energy E is 212.2kJ·mol^-1, the frequency factor A is 1.3×10²² s^-1, and T_D24 is 123.0°C, which are calculated by the velocity constant method. The studies have revealed that, comparing with SF-3, SZQu-1 has worse thermal stability and stronger explosiveness.

Abstract: A novel flame retardant additive, DOPO-based polymeric phosphate (PFR-D), which simultaneously contained phosphorus and sulfur, was synthesized from 9,10-dihyro-9-oxa-10-phosphaphnanthrene-10-oxide (DOPO), POCl₃ and bisphenol S. And the structure of PFR-D has been characterized by ¹H-NMR, ³¹P-NMR and FT-IR. PFR-D was used as additive in polycarbonate/acrylonitrile-butadiene-styrene alloy (PC/ABS). The UL94 V-0 rating was achieved by addition of 5-7% PFR-D in PC/ABS, the LOI reached 27.5%. The thermal degradation of PFR-D and polymers with it was investigated by TGA, and the results showed that addition of PFR-D apparently changed the pyrolysis pathways of PC/ABS. The TGA curves indicated that the flame retardant effect was attributed to promoting the char yield by involving the polymer in charring.

Abstract: The problem of stability of the polymer rod in creeping was solved by energy method in the form of Timoshenko and Ritz. Possible displacements of the points were given in the form of a trigonometric series with undetermined coefficients. Results obtained numerically using complex Matlab under different constraint equations between creep deformations and stresses. There are shown the necessity of taking into account the "junior" component of high-elastic deformation by using the Maxwell-Gurevich equation.

Abstract: With the method of solution polymerization, we prepared a high conversion rate and larger molecular weight acrylate copolymer. Using synthetic copolymer, low temperature stripping material was compounded with the proportional certain kinds of crosslinking agent, plasticizer, thickener and release agent, according to the certain reaction temperature and the loading sequence. The material mechanical properties, stripping, decontamination rate was tested and characterization. We got the strip materials meeting the low temperature environment. Finally, the influence factors of copolymerization reaction: the choice of solvent, dosage of initiator, monomer and the dosage was discussed. To achieve higher conversion rate and larger molecular weight acrylate copolymer, the method of solution polymerization was adopted in this study. Low temperature stripping material was compounded with synthetic copolymer, together with crosslinking agent, plasticizer, thickener and release agent in certain proportion, according to reaction temperature and the loading sequence. This material’s mechanical properties, stripping, decontamination rate were tested and characterizing definition was done. Results showed this strip material could meet the requirement of low temperature environment. Finally, the influence factors of copolymerization reaction were discussed, including the choice of solvent, dosage of initiator, monomer and the dosage.

Abstract: This paper evaluate how colorimetry change of ethylene propylene diene rubber (EPDM)/Aluminium oxide (Al₂O₃) composites when added with four types of crystallized resins. The results indicate that the filler Al₂O₃ can turn EPDM control from lighter, redder, and yellower to darker, greener and bluer, respectively. The total color change (ΔE) of EPDM/Al₂O₃ composites increase with the decrease amount of crystal lattices. EPDM/Al₂O₃/Polypropylene (PP) composite, with the highest crystallinity of PP, has little change of the lightness value and the total color change of EPDM compostes due to light scatter.

Abstract: Poly (3-hexylthiophene) (P3HT) was synthesized by a modified simple FeCl₃ oxidative polymerization. The use of mixed solvents provides a low-cost and effective method to prepare the higher ordered P3HT. The SEM result shows that the assembling of P3HT tends to produce nanowires with 1, 4-dioxane as the poor solvent. The XRD result shows that the formation of P3HT nanowires can enhance the order and regularity of the polymer. The conformation transformations of P3HT chains were analyzed by ultraviolet visible light absorption spectrum. The results show that the higher ordered P3HT was obtained. The higher ordered P3HT can improve the utilization rate of the sunlight when applied in solar cells.

Abstract: Polyether-modified polysiloxane was synthesized by hydrosilylation, using allylic alcohol polyether and polysiloxane as materials, toluene as solvent and chloroplatinic as catalyst. The effect of technology conditions on conversion rate of hydrogenous silicone oil was discussed and chemical structure of product was characterized. The results show that the optimum technology is: the reaction temperature is 95°C, time is 5h, the molar ratio of polysiloxane to polyether is 1:1.2, the dosage of catalyst is 30ug/g and the mass fraction of the toluene is 25% of the system.

Abstract: The micro-sized p(styrene-1,4-divinylbenzene)/polyacrylamide(p(St-DVB)/pAM) particles were prepared by a two-step method. P(St-DVB) cores were firstly obtained via concentrated emulsion polymerization, and then the cores were swelled sufficiently and reacted with acrylamide until p(St-DVB)/pAM particles were obtain. The morphologies and compositions of p(St-DVB)/pAM particles were characterized by scanning electron microscopy(SEM) and infrared spectroscopy(IR) individually. It was proved that the micro-morphologies of p(St-DVB)/pAM particles were nearly spherical or even peanut shape. It was also found that the diameter distribution of p(St-DVB)/pAM particles became narrower with the increasing of DVB amounts, and the same trade was also observed on emulsifier amounts.

Abstract: Oxidative stable hybrid thermosets derived from silicon-containing polyarylacetylene (PSA-V) and branched methylvinylcyclosilazane (b-MVSZ) have been prepared, and b-MVSZ was synthesized by coammonolysis reaction of methylvinyldichlorosilane and vinyltrichlorosilane, which was characterized by using GC-MS, FT-IR, ¹H NMR and GPC. The cure behaviors of PSA-V/b-MVSZ hybrids were investigated by DSC and the thermal and oxidative stabilities of the cured PSA-V/b-MVSZ hybrids were determined by TGA under nitrogen and air atmosphere. The results indicated that the PSA-V/b-MVSZ hybrids could be thermally cross-linked through the vinyl/ethynyl groups to form polymer networks. The cured PSA-V/b-MVSZ hybrids possessed high thermal stability, and with increasing the content of b-MVSZ, the thermooxidative stability of the hybrid materials was enhanced.

Abstract: The Czochralski silicon (CZ-Si) samples were irradiated with 1.5 MeV electrons and annealed at 200 - 450 °C. It was investigated the effect of irradiation dose and interstitial oxygen content [O_i] on VO concentration by Fourier transform infrared spectroscopy (FTIR). The results show that VO concentration increases with irradiation dose but not linear increase. The interstitial oxygen content has no effect on VO concentration. The VO intensity increases firstly and then decreases after annealing in samples with low oxygen content. The VO disappears at 450 °C. In high oxygen content samples, VO exhibits thermal stability and disappears at 400 °C.