Preparation of a polyacrylonitrile fiber from a mixture of an acrylonitrile-methyl methacrylate copolymer and a polyurethane

Conclusions The most stable solutions of mixtures of polyacrylonitrile with polyurethane (containing the heterocyclic triazine ring in the main chain) with an optimum size of the disperse phase particles were obtained at a component ratio of 95:5.Introduction of 5% by wt. of polyurethane into the make-up of a polyacrylonitrile fiber made it possible to increase the resistance of the fiber to abrasion, double bending, and repeated extension.Translated from Khimicheskie Volokna, No. 1, pp. 42–43, January–February, 1985.     

相对分子质量及其分布对稀土顺丁橡胶性能的影响

研究了5种不同相对分子质量及其分布的稀土顺丁橡胶(NdBR)的性能。结果表明,NdBR生胶和混炼胶的门尼黏度随相对分子质量的增加而升高;窄相对分子质量分布(多分散指数小于3.00)NdBR的生胶门尼黏度略高于与其相对分子质量相近而分布较宽的NdBR。相对分子质量对NdBR的正硫化时间影响不大,但最小转矩和最大转矩有随相对分子质量的增加而增大之趋势。生胶相对分子质量较低的NdBR,其硫化胶的300%定伸应力和拉伸强度较低,生热值较高,耐磨性能下降,滚动阻力升高。生胶门尼黏度为39~49的NdBR,其硫化胶的综合性能良好。填充适量操作油可以提高硫化胶的物理机械性能。窄相对分子质量分布NdBR硫化胶的300%定伸应力、拉伸强度、扯断伸长率、回弹性、永久变形、耐磨性以及滚动阻力等都优于相对分子质量相近而分布较宽的NdBR。     

Abrasion resistance of thermoplastic polyurethane materials blended with ethylene–propylene–diene monomer rubber

The effect of ethylene–propylene–diene monomer rubber (EPDM) as an additive on the abrasion resistance of a thermoplastic polyurethane (TPU) resin was investigated. The mechanical properties and microstructure of the resultant TPU/EPDM composites were evaluated, and the surface morphology of the composites after abrasion testing was examined. The results showed that the addition of EPDM greatly improved both the mechanical properties and abrasion resistance of the TPU resin. A TPU/EPDM composite with 8 wt % EPDM demonstrated the highest tensile strength, the largest elongation at break, and the best overall performance. The abrasion of this composite was 27 mg, whereas that of the pure resin was 73 mg. With the further addition of EPDM, the abrasion resistance of the resultant composites decreased, whereas the viscosity increased. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of additions of oligomeric epoxides on the physicochemical properties of cellulose acetates

Conclusions The effect of oligomeric epoxides based on polyethylene oxide and epichlorohydrin, having an epoxy group content of 8–15%, on the physicochemical and structural—mechanical properties of solutions and films of CA has been described.It has been shown that, in the first stages of degradation, the modifiers are effective thermostabilizers (at a content from 0.5 to 10% of the weight of the CA).The devitrification region of the modified specimens is shifted in the low-temperature direction by 5–33°C on increase of the oligomer content from 2 to 15%; the relative elongation rises by a factor of 1.2 to 3.Under the influence of the modifiers, the viscosity and turbidity of concentrated CA solutions are reduced; the specific bulk electrical resistance of films containing modifiers is reduced by several orders of magnitude.Translated from Khimicheskie Volokna, No. 3, pp. 45–46, May–June, 1984.     

过氧化物硫化体系对CM／XNBR共混物性能的影响研究

研究了不同用量过氧化物硫化体系对氯化聚乙烯橡胶（CM）／羧基丁腈橡胶（XNBR）共混硫化胶各相交联密度及热空气老化前后的物理机械性能、耐油性能等的影响规律。结果表明,随硫化体系用量的增加,共混硫化胶两相的交联密度都明显增加,交联密度差值变大;焦烧时间逐渐降低;硬度、拉伸强度、100％定伸应力、体积磨耗量呈上升趋势,永久变形、扯断伸长率明显降低,撕裂强度整体变化不大,常温下体积和质量变化率均很小,高温下体积和质量变化率明显降低后趋于平稳;热空气老化后,硬度、拉伸强度、100％定伸应力、撕裂强度整体上升,扯断伸长率整体下降,体积磨耗量整体变化不大;热油老化后,拉伸强度、100％定伸应力变化不大,扯断伸长率明显降低。     

SSBR2535基本性能的研究

探讨国产新型充油高乙烯基溶聚丁苯橡胶SSBR2535的基本性能。结果表明，与国外同类产品相比，SSBR2535生胶门尼粘度低；混炼胶的门尼松弛面积小，硫化速度快，强度高；硫化胶定伸应力和拉伸强度低，拉断伸长率和撕裂强度高，耐疲劳性能好，耐热老化性能略差，滚动阻力、抗湿滑性能和耐磨性能平衡性好，可在轮胎工业中推广应用。     

Mechanical,morphological, and thermal properties of (thermoplastic polyurethane)/(chlorinated polyethylene) blends

The preparation and characterization of CPE (chlorinated polyethylene)/TPU (thermoplastic polyurethane) blends with various ratios were investigated. The compatibility, morphology, and rheology, as well as the thermal and physico‐mechanical properties, were studied by differential scanning calorimetry, Fourier‐transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, universal tensile machine analysis, and capillary rheometry. The results showed that CPE is partially miscible with TPU. The introduction of CPE into TPU resulted in a reduction of the viscosity, tensile strength, tear strength, compression set, abrasion resistance, and hardness, whereas the elongation at break was increased. Thermogravimetric analysis showed that the blends underwent two stages of thermal degradation. J. VINYL ADDIT. TECHNOL., 19:192‐197, 2013. © 2013 Society of Plastics Engineers     

二硫化钼对NBR胶料性能的影响

探讨微米二硫化钼对NBR胶料加工性能、物理性能和耐磨性能的影响。结果表明，机械共混不会破坏二硫化钼的层状晶体结构，二硫化钼粒子与橡胶基体界面结合较差；二硫化钼用量增大，胶料的加工性能变化不大，硫化胶的定伸应力提高，拉伸强度和拉断伸长率降低，摩擦因数减小，耐磨性能变劣。微米二硫化钼不能提高NBR硫化胶的耐磨性能。     

Preparation and properties of viscose staple fibre modified by grafting polyvinyl chloride

Conclusions 1. The authors have obtained modified viscose fibres containing PVC in amounts reaching 25–230% of the weight of cellulose. The molecular weight of the grafted chain varies between 40,000 and 140,000; the degree of conversion of cellulose does not exceed 13–22%.2. It is shown that grafting of PVC increases the absolute strength and elongation of fibres, reduces the loss of wet strength, and reduces the resistance to repeated bending. A marked reduction of the fibre number reduces their strength.3. The results are explained by the probability that graft copolymerization takes place on a supramolecular level.Moscow Textile Institute. Translated from Khimicheskie Volokna, No. 5, pp. 30–32, September–October, 1969.     

Effect of ultraviolet irradiation on the retention of physicomechanical properties in fabrics made of pneumatically texturized yarns

Conclusions -- Ultraviolet irradiation very sharply reduces such properties of fabrics as resistance to abrasion and resistance to double bending. To a smaller extent, the breaking characteristics and crease resistance of fabrics are reduced, depending on the duration of exposure.-- The results obtained make it possible to give recommendations on a fabric structure which ensures high resistance to the action of ultraviolet radiation. The basis for this is development on the fabric surface of a light-resistant system of yarns in such an amount that it covers the weaker yarn system.Translated from Khimicheskie Volokna, No. 4, pp. 51–52, July–August, 1991.     

A study on the compatibility and physical properties of chlorinated polyethylene rubber/nitrile rubber blends

The miscibility and some physicomechanical characteristics of chlorinated polyethylene rubber (CPE) and nitrile rubber (NBR) blends have been investigated. Calculation of the heat of mixing, differential scanning calorimetry, and scanning electron microscopy analysis showed that CPE was miscible with NBR in all proportions. The cure and scorch times decreased with the increase in NBR content, whereas the maximum torque increased. The tensile strength, 100% modulus, elongation at break, tear strength, and compression set decreased with increasing of NBR content. After aging, hardness and tensile strength increased, and there was no drastic change in elongation at break on aging. The thermal aging resistance and the abrasion resistance of NBR are improved after blending with CPE, but the oil resistance decreased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

充油量对稀土催化本体聚合丁二烯—异戊二烯橡胶性能的影响

采用５种充油量对稀土催体体聚合丁二烯（Ｂｄ）－异戊二烯（Ｉｐ）共聚橡胶的加工工艺和硫化胶性能进行了研究。实验结果表明，随着充油量的增加，生胶ＭＬ值、屈服强度和拉伸强度均下降，可塑性增加，扯断伸长率变大，混炼行为变佳，胶料挤出性能由“劣“等转变为“中等“等。硫化胶的扯断伸长率随充油量的增加而增大，而拉伸强度在充油量为３０～４０份时出现极大值，湿滑指数和拉伸耐寒系数随充油量的增加而增加，充油量超过２０     

High-temperature abrasion of refractories

Conclusions The most rapid abrasion in dinas refractories occurs in the 700–900°C range; periclase 800–1000°C; mullite-corundum articles exhibit a smooth increase in abrasion with rise in temperature. The abrasion of refractory concretes is much higher than for bricks.It is possible by determining the abrasion resistance to carry out quality control of the firing process, and also to check the quality of linings made from concretes.Translated from Ogneupory, No. 1, pp. 13–14, January, 1991.     

充油反式-1,4-聚异戊二烯橡胶的研制及性能

采用干法充油工艺,对用负载钛体系催化异戊二烯本体沉淀聚合得到的高门尼粘度反式-1,4-聚异戊二烯(TPI)的充油工艺性能及充油橡胶的性能进行了研究.结果表明,随着充油量的增加,充油生胶的可塑性增大,混炼行为得以改善,但高填充油份数的生胶放置中有喷油现象;充油生胶的屈服强度、拉伸强度、拉断伸长率、定伸应力均下降;充油硫化胶的拉伸强度、拉断伸长率、100%定伸应力及回弹值均下降,撕裂强度在充油量为37.5份时出现极大值,硬度先增大到极大值后又略有减小,磨耗量增大,抗湿滑性提高.综合考虑,高门尼粘度TPI充油量以37.5份左右为宜.     

Study of rheological,thermal, and mechanical behavior of reprocessed polyamide 6

The effect of reprocessing Polyamide 6 (PA6) has been studied in this article. To simulate recycled PA, we reprocessed virgin PA through five cycles. The PA 6 has undergone mechanical, thermal and rheological characterization after the various cycles of reprocessing in order to evaluate the corresponding properties and correlate them with the number of cycles undergone. In order to widen our injection simulation analysis by computer (CAE: Computer Aided Engineering) of these new materials, it was necessary to determine the viscosity using a mathematical model; in this case the Cross‐WLF, to determine the relevant parameters. Our results show that tensile strength, elongation at break and hardness remain practically constant, while the charpy impact decreases as the number of reprocessing cycles increases. The effects of reprocessing on the material may decrease the rheological properties; specifically the viscosity of the material decreases with increasing processing cycles. The thermal properties are also influenced with the reprocessed material. The crystallinity increases and the degradation reaction will be advanced to increase the reprocessing cycle. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Effect of sulfuric acid treatment on the physicomechanical properties of polyphenyleneoxadiazole fibres

Conclusions By treatment of undried polyphenyleneoxadiazole yarns with concentrated sulfuric acid under isometric conditions, it is possible to raise their strength by 20–30% and their elongation at break 40–50%.The improvement in physicomechanical properties of the yarns which have been treated with acid is caused by a reduction in internal stresses, an improvement in the interlayer packing of the macromolecules fragments, and an increase in the degree of orientation of the macromolecules.Translated from Khimicheskie Volokna, No. 6, pp. 33–35, November–December, 1985.     

利用正交试验探讨乙丙橡胶的再生

采用正交试验法考察了再生温度、时间、石蜡油的用量、活化剂480的用量对乙丙橡胶再生胶的门尼粘度、密度、拉伸强度和扯断伸长率的影响。结果表明,石蜡油的用量对门尼粘度、密度和拉伸强度影响最大,随着石蜡油的用量的增加,门尼粘度、密度和拉伸强度降低;再生温度对扯断伸长率的影响最大,随着再生温度的升高,扯断伸长率降低。     

填充油的种类对Fe系1,2-聚丁二烯性能的影响

研究了芳烃油和环烷烃油对充油铁系1，2-聚丁二烯橡胶性能的影响。结果表明，基础胶充油后门尼粘度值下降，可塑性增加，混炼行为变佳；填充芳烃油比填充环烷烃油的橡胶在拉伸强度、撕裂强度、伸长率和生胶门尼值等方面均有所提高；充油后虽然硫化胶硬度降低，但是生热和耐磨性能提高。填充芳烃油可适当提高硫化胶的抗湿滑性，但滚动阻力也升高。环烷烃油可降低硫化胶的滚动阻力。充油可适当改善胶料的抗老化性能。     

三元尼龙对丁腈橡胶力学性能及耐介质性的影响

采用三元尼龙改性丁腈橡胶（NBR）,研究尼龙用量对NBR混炼胶加工工艺性能和硫化胶力学性能、耐老化性能、耐介质性能的影响。结果表明：尼龙的添加有效地提高了NBR硫化胶的强度以及耐磨性能,老化性能也得到改善,拉伸强度基本上是随着尼龙用量的增加而增大,其中尼龙用量为5phr时,硫化胶的综合物理机械性能较好;耐油系数亦随阻尼用量的增加而逐渐增大,尼龙的加入提高了硫化胶的耐热油性;耐混合溶剂后的体积变化率随着尼龙用量的增加而逐渐降低。     

Physicomechanical properties of acetate fibres modified with nitromethane vapors

The physicomechanical characteristics of acetate fibres were investigated in different stages of their spontaneous elongation in nitromethane vapors. It was shown that acetate fibres are strengthened and the coefficients of variation for the breaking strength and elongation at break decrease at the beginning of treatment with vapors of a specific solvent. A hypothesis was advanced concerning the possible mechanism of the reaction of the polymer with the solvent vapors in which it forms a mesophase.Translated from Khimicheskie Volokna, No. 1, pp. 50–53, January–February, 1995.