衰减全反射红外显微光谱法研究炭黑补强橡胶的老化

1前言 炭黑（CB）填充橡胶被认为是红外光谱（IR）极端困难表征的试样，因为橡胶对IR光有极强的吸收和散射。由于难以取得足够薄的试样，所以采用透射红外光谱对实际橡胶试样进行测试几乎不可能。然而。用溴化钾（KBr）稀释的CB填充二烯烃橡胶的透射试样是有用的，制成超薄切片就可以进行透射测试。     

辐照对橡胶老化作用的研究

在核能、航空航天、电离辐射等高能粒子辐照领域,辐照是引起橡胶性能降低的主要因素之一。介绍辐照对橡胶的损伤机理、不同射线粒子辐照对橡胶性能的影响,分析橡胶耐辐照性能的评估指标和几种常见橡胶的耐辐照性能,提出橡胶耐辐照性能的改进方法。辐照对橡胶的老化损伤主要是因为橡胶分子链吸收一定量的辐照能而断裂,生成大量自由基,进行不同程度的降解和交联反应,进而改变了橡胶的化学、机械及电气性能。不同辐射源对橡胶的老化作用差异较大,目前没有一种橡胶可完全满足各种工况环境的使用要求,在实际使用工况下应选择合理的性能指标来评估橡胶经辐照后的性能稳定性。除了选用耐辐照橡胶之外,还可以通过添加填料、抗辐射树脂或有机抗辐射剂等方式进一步改善橡胶制品的耐辐照性能,拓宽橡胶制品应用范围。     

端羟基聚丁二烯液体橡胶老化性能研究

研究了不同防老剂种类及用量,不同环境温度条件下,端羟基聚丁二烯（ＨＴＰＢ）液体橡胶粘度变化规律。结果表明,加入防老剂,尤其是２２４６可以显著改善ＨＴＰＢ的老化性能,且防老剂２２４６最佳用量为０．２％￣０．５％,室温下,ＨＴＰＢ不加防老剂的贮存期长达１年。     

国内外钕系聚丁二烯橡胶生产技术

介绍了钕系聚丁二烯橡胶的生产状况和生产技术特点，从催化体系、聚合工艺和改性技术三方面综述了钕系聚丁二烯橡胶的技术研发热点，提出了我国钕系聚丁二烯橡胶的发展建议。     

橡胶及其制品老化的研究进展

介绍橡胶及其制品老化的研究进展。橡胶及其制品老化主要有热氧老化、介质老化、辐照老化、自然老化和气体氛围老化等。当前对于橡胶及其制品的老化研究主要集中在热氧老化方面,对其他方式老化的研究较少,且对于老化降解机理的研究还不够深入。未来橡胶及其制品的研究方向是更好地控制且利用老化效应,以保证橡胶及其制品良好的使用性能及较高的使用效率。     

橡胶的老化现象及其老化机理

橡胶或橡胶制品,在使用或贮存过程中,由于受到热能、机械能、光能和辐射能的作用,加上氧、臭氧、水分和变价金属、金属离子参与的化学反应,致使橡胶产生了老化现象,失去使用价值。本文阐述橡胶或橡胶制品产生的老化现象及其老化机理。     

橡胶沥青紫外老化过程的探索

研究了橡胶沥青在紫外光老化过程中结构与性能变化规律。以软化点为指标分析橡胶沥青在紫外老化条件下性能的变化,发现其软化点增长速度慢于基质沥青,羰基、亚砜基吸收峰的变化小于基质沥青。结果表明,橡胶沥青相对基质沥青具有较强的耐紫外老化性能。     

傅立叶变换红外光谱法在橡胶分析中的应用与进展

简介了用橡胶分析的傅立叶变换红外光谱透射法，漫反射ＦＴＩＲ法，衰全反射ＦＴＩＲ法，ＦＴＩＲ－光声光谱法，ＦＴＩＲ仪与各种仪器的联用，以及计算机技术在ＦＴＩＲ分析中的应用与进展。     

聚丁二烯橡胶生产技术进展

分析了近几年国内聚丁二烯橡胶的生产情况,介绍了聚丁二烯橡胶的生产技术进展,其中包括催化剂配置技术、分子量调节技术和聚丁二烯橡胶的改性处理等,最后展望了聚丁二烯橡胶的发展趋势.     

Mechanical aging behavior of styrene‐butadiene rubbers evaluated by abrasion test

The ring‐shaped styrene‐butadiene rubbers (SBRs) test pieces ran on a rotating stainless‐steel ring using an abrasion tester to evaluate the changes in the mechanical properties, such as the tensile storage modulus and tan δ values, the modulus at 300% elongation, and the strength and extension ratio at the breaking point, after a mechanical aging process. The surface of the SBR test pieces and the formed rubber debris after the running experiment was investigated using scanning electron microscopy. A change in the crosslinking density of the SBRs and the analysis of the isolated free polymers showed the occurrence of bond scission of the copolymer chains. On the other hand, the mechanical properties of whole SBR samples showed only a small change during the mechanical aging test. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Quantitation of estolides by Fourier transform infrared spectroscopy

Estolides were produced from meadowfoam oil fatty acids, oleic, linoleic, petroselinic, andcis-5,cis-13 docosadienoic acids. Estolide reaction mixtures were quantitated by Fourier transform infrared spectroscopy and compared to the area percentages determined by high-performance liquid chromatography. The absorbance frequency of estolide carbonyl (1737 cm⁻¹) is different than the lactone carbonyl (1790 cm⁻¹) and the acid carbonyl (1712 cm⁻¹). Estolide standards were obtained by wiped-film molecular-still distillations and column chromatography.     

Gamma radiation effect of polymethylvinylphenylsiloxane rubbers under different temperatures

The gamma radiation effect on polymethylvinylphenylsiloxane (PMVPS) rubbers is investigated by irradiation exposure of PMVPS rubbers to a maximum dose of 200 kGy in the temperature range 28–110 °C. Compared with unirradiated PMVPS rubber, the elongation at break of irradiated PMVPS rubber decreases while its elastic modulus increases with the increase of absorbed dose or radiation temperature. DSC, ATR‐FTIR, XPS, and ¹H‐NMR indicate that slight degradation and oxidation reaction occur during the irradiation of PMVPS. Solvent swelling and gel fraction study confirms that the crosslinking density of PMVPS rubbers increases gradually with increasing absorbed dose or radiation temperature. Therefore, radiation‐induced crosslinking of PMVPS is dominant reactions for the chosen dose or temperature range. Furthermore, synergistic effect exists in the high‐temperature radiation process for PMVPS rubbers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45404.     

Fourier transform infrared spectroscopy study of poly(1‐trimethylsilyl‐1‐propyne) aging

The influence of various factors on the aging of poly(1‐trimethylsilyl‐1‐propyne) (PTMSP) during long‐term storage in air was investigated with Fourier transform infrared spectroscopy. Most attention was paid to the differentiation of oxidation, the reduction of the free volume, and the absorption of low‐molecular‐weight compounds from the environment. IR spectra of PTMSP samples stored from 1–2 months to 6.5 years revealed C?O, C? O, and C? H bands that had been earlier attributed to polymer oxidation products. It was established, however, that these bands completely disappeared from IR spectra of the aged samples after their soaking in ethanol. Spectra of dried residues of ethanol extracts displayed all these bands and did not show any bands of polymer chain fragments. Gas chromatography/mass spectrometry analysis proved that the residues were composed mainly of various dialkyl phthalates. Special experiments showed that PTMSP films easily absorbed di‐n‐butyl phthalate vapors. IR spectra of the films stored for a long time showed no decrease in double‐bond and methyl group bands. It was concluded that the polymer did not undergo oxidation in air at room temperature for at least 6.5 years. The absorption of plasticizer vapors (and possibly other compounds) from the environment and the reduction of the free volume were the main reasons found for PTMSP aging. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2523–2527, 2007     

Fourier transform Raman and Fourier transform infrared spectroscopy studies of silk fibroin

The chemical and conformational structures of Bombyx mori silk were studied with the complementary techniques of Fourier transform Raman spectroscopy and Fourier transform infrared spectroscopy. The Fourier transform Raman spectrum of silk showed strong bands for the photosensitive aromatic amino acids tyrosine, tryptophan, and phenylalanine. Intensive UV/ozone irradiation reduced the Raman intensities of the amide III band and the tyrosine signals due to peptide chain scission of the silk polymer and the photochemical changes in the tyrosine residues on the silk molecules. However, the Raman spectroscopy changes for tryptophan were less clearly defined because of peak overlapping with other amino acid signals and the low concentration of tryptophan. The Fourier transform infrared (attenuated total reflectance) technique, coupled with second‐derivative spectroscopy analysis, demonstrated a decrease in the crystallinity degree and tyrosine content of UV/ozone‐irradiated silk, as indicated by changes in the Fourier transform infrared bands of amide III doublet and tyrosine signals. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1999–2004, 2005     

傅里叶变换红外光谱法测定B–GAP羟值

为解决支化聚叠氮缩水甘油醚(B–GAP)羟值测试不稳定的问题,选用异氰酸苯酯对B–GAP进行衍生处理使羟基转化成酯基,采用傅里叶变换红外光谱法测定产物中酯基的吸光度以间接得到B–GAP羟值;研究了衍生时间、异氰酸苯酯用量等对测定结果的影响。结果表明,B–GAP羟值与衍生后分子链中酯基的红外特征峰吸收峰强度之间可进行定量关联,用该方法测定羟值,具有较好的重复性和较高的准确度。     

我国镍系顺丁橡胶聚合技术进展

评述了我国镍系顺丁橡胶聚合技术的进展,包括催化剂陈化技术的完善,加水技术的应用,终止技术的改进等。提出了提高我国镍系顺丁橡胶聚合技术的建议。     

Fourier transform infrared photoacoustic spectroscopy of raw coal

Photoacoustic Fourier transform infrared (PA-FT-i.r.) spectrometry was employed to examine raw coal containing 13–64 wt%, daf volatile matter (VM). Sample preparation for i.r. examination was the same as for ASTM proximate analysis. Technological and spectroscopic information on representative samples were obtained. PA scan time is longer than for conventional FT-i.r. operation; however sample preparation is faster and easier. The time-consuming KBr pellet technique, possibly affecting coal structure, is avoided. The i.r. absorption in the OH, NH, CH_ar and CH_x,al regions may allow the determination of VM for both high- and low-rank coal. Some differences between present PA and diffuse reflectance spectra of raw coal from the literature are discussed.     

Stability determination of soy lecithin-based emulsions by Fourier transform infrared spectroscopy

The stability of soy lecithin-stabilized emulsions was determined by Fourier transform infrared spectroscopy. Oilin-water (o/w) emulsions were prepared with 6% (vol/vol) medium-chain triglycerides (MCT), 94% (vol/vol) water, and 4% (wt/vol) Lecigran and Lecimulthin soy lecithin. There were little or no differences between the 4% Lecigran and 4% Lecimulthin emulsions for all vibrational regions studied (OH at 3348 cm⁻¹, C=O at 1741 cm⁻¹, PO and C−O−C at 1157 cm⁻¹, and P−O−C at 1101 cm⁻¹), but the control emulsion, without emulsifier, had increased vibrations as the emulsion separated. The weaker vibrations of the more stable emulsions were probably due to reduced molecular interaction at the interface. However, added magnesium or calcium chloride enhanced the vibration of these groups, probably by disrupting the lecithin interaction at the emulsion interface.