自然环境贮存条件下氟硅橡胶的寿命预测

对氟硅橡胶材料在全国5个典型气候地区万宁、漠河、敦煌、西双版纳和济南进行了库内贮存试验,分析了不同地区自然老化过程和受力状态(压缩率为25%)下材料力学性能的变化情况。结果表明,压缩永久变形保留率可以作为老化寿命的参考指标,以此建立了5个地区氟硅橡胶受力状态下的贮存寿命方程,利用二分法和线性回归估计确定了氟硅橡胶库内贮存寿命方程中的相关参数,并以压缩永久变形保留率下降到50%作为材料的老化指标,在95%的置信水平下,预测出5个地区氟硅橡胶的寿命由短到长依次为:西双版纳419 d、万宁944 d、济南1 043 d、敦煌2 031 d、漠河3 330 d。     

FEX-1挠性炸药贮存寿命的预估

采用提高温度加速老化与测定试样力学性能相结合的方法，依据挠性炸药(FEX-1)扯断永久变形随温度和时间的变化规律，预估该炸药在常温下的贮存寿命为11．8年。     

热空气老化下黏弹性阻尼硅橡胶寿命预测模型

以压缩永久变形为寿命分析研究对象,研究了常用工况下老化时间对黏弹性阻尼硅橡胶的储能模量、损耗模量及损耗因子的影响,同时采用热空气加速老化试验方法探究了黏弹性阻尼硅橡胶在不同温度（348,363,378,393 K）下压缩永久变形性能保持系数随老化时间的变化规律,并通过对两种老化动力学模型进行研究分析和修正获得了黏弹性阻尼硅橡胶的老化反应速率,此外,还对不同老化动力学模型下老化反应速率对Arrhenius模型的非线性行为进行了分段研究,推测了黏弹性阻尼硅橡胶的储存寿命。结果表明,在室温（298 K）下两种老化动力学模型在储存寿命为10.0 a时的压缩永久变形性能保持系数均为0.60;当选择压缩永久变形性能保持系数为0.50作为失效判据时,黏弹性阻尼硅橡胶的储存寿命分别为20.0 a和19.2 a,使用两种模型所得黏弹性阻尼硅橡胶的储存寿命误差仅为4%。     

基于高温加速试验的点火药盒贮存寿命预估

采用高温老化方法,研究了点火药盒的老化失效规律,预估了其贮存寿命。研究结果表明,点火药盒没有早期失效,失效时间分布集中,其失效机理为赛璐珞壳体老化,失效模式为材料力学性能下降导致壳体破坏。点火药盒贮存寿命与温度的关系符合Arrhenius方程。评估结果表明,点火药盒的常温贮存寿命大于12年的设计指标要求。     

硅橡胶混炼胶压缩永久变形性能的改善

探讨了市售硅橡胶混炼胶（sPF1151）的压缩永久变形性能及其改善对混炼胶力学性能的影响。获得了改善硅橡胶混炼胶压缩永久变形性能的适宜配方和工艺。     

低压缩永久变形硅橡胶

本文介绍了一些具有优良低压缩永久变形和热老化特性的新型乙烯基硅橡胶胶料,可用作快速硫化硅橡胶垫圈材料和液体注压胶料。     

发射药加速寿命试验的相关性研究

用Ｓｐｅａｒｍａｎ的秩相关检验法和相关系数法定量地分析了某种发射药温度单应力加速寿命试验与现场贮存试验之间的相关性。结果表明，两者显著相关。给出了相关方程及两者之间的加速系数。     

硅橡胶海绵密封条压缩永久变形性能的研究

研究了发泡剂、硫化剂种类及用量对硅橡胶海绵密封条压缩永久变形性能的影响。结果表明,发泡剂AZ、硫化剂DCBP/BPO并用制得的硅橡胶海绵密封条具有较小泡孔和较低压缩永久变形,制品表面光滑。     

低苯基硅橡胶压缩永久变形性能的研究

比较了不同捏合工艺下热硫化低苯基硅橡胶的压缩永久变形性能。发现捏合时间对低苯基硅橡胶的压缩永久变形性能有显著影响。随着捏合时间的延长,压缩永久变形性能先降后增,当捏合时间达到150 min时,压缩永久变形性能趋于稳定;继续延长捏合时间,压缩永久变形性能变大;随着热空气老化温度的升高,低苯基硅橡胶的压缩永久变形变大,在300℃×12 h条件下压缩永久变形可达100%,基本丧失了回弹能力;随着热空气老化时间的增加,低苯基硅橡胶压缩永久变形变大,在200℃×1 200 h、250℃×72 h、300℃×12 h老化后,低苯基硅橡胶的压缩永久变形达到100%,基本丧失了回弹能力。     

硅橡胶O形密封圈不同预压缩条件下压缩永久变形的比较研究

使用同一批次胶料制备了2组硫化试样并分别按HG/T 3087-2001和GB/T 27800-2011研究了预压缩条件对寿命预测结果的影响程度。结果表明,在同一老化温度及同一老化时间下,依据HG/T 3087-2001预压缩的试样压缩永久变形率与依据GB/T 27800-2011预压缩的试样无明显差异;由此证明,HG/T 3087-2001和GB/T 27800-2011压缩永久变形率测试试验基本不存在数据差异。     

特种氯丁橡胶热氧老化研究

通过对特种氯丁橡胶在热空气中进行加速老化,比较了其老化前后性能的变化,得出了该橡胶的性能变化与老化时间的函数关系,并建立了100％定伸应力、拉伸强度、断裂伸长率、强韧度、撕裂强度与邵尔A硬度之间的关联关系。结果表明：在整个老化期间,100％定伸应力、硬度逐渐增加;拉伸强度、断裂伸长率、强韧度、撕裂强度逐渐降低;机械性能与硬度呈线性关系。     

Effect of gel on crystallization behavior of natural rubber after accelerated storage hardening test

Crystallization of natural rubber (NR) and purified NR after storage hardening of the rubbers under dried condition with phosphorus pentoxide was investigated by dilatometry and polarized light microscopy. The purified NR was prepared by removing proteins and fatty acid ester groups from fresh NR (FNR) through deproteinization and transesterification, respectively. The rubbers were characterized in regard as gel content, ester content and crosslink density. Nucleation (I) and growth rates (V) of the gel fraction estimated from the number of spherulites and their sizes observed in the course of isothermal crystallization depended on supercooling (ΔT = T_m⁰ ? T). T_m⁰ is equilibrium melting temperature and T is absolute temperature. Slope of linear line in a plot of logarithmic V versus 1/TΔT for NR was independent of time for storage hardening, suggesting that the lateral surface free energy and diffusion were little function of branching and crosslinking. The rate of crystallization of FNR significantly decreased when the crosslink density increased. Since the overall crystallization is functions of chain mobility and surface free energy, the slower crystallization of well crosslinked FNR may be attributed to the less chain mobility and small value of Δσ due to the formation of crosslinked and branched entities. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Study on variation of structure and properties of natural rubber during accelerated storage

The dynamic variations of molecular structure and properties of natural rubber (NR) during the accelerated storage have been studied. The results showed that, with the prolonging of the storage time, the average molecular weight and the gel content increased, the width index of molecular weight distribution decreased, the gel size increased gradually, but the crosslinking density of gel fluctuated only within a narrow range. Besides, the initial plasticity increased, whereas the plasticity retention index decreased. The studies with thermal analyses and infrared spectroscopy showed that the thermal degradation temperature dropped, the thermal degradation rate increased, and the thermal stability has decreased after the storage of NR. The molecular structure and properties of NR are in a state of dynamic variation during accelerate storage. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1779–1783, 1998     

甲基乙烯基硅橡胶加成硫化研究

探讨了甲基乙烯基硅橡胶中乙烯基含量、多乙烯基硅油、舍氢硅油和氟铂酸对加成硫化硅橡胶物理机械性能的影响。结果表明．在150份乙烯基质量分数为0．13％的硅橡胶中加入1份硅氢基质量分数为1．65％的舍氢硅油、2份乙烯基质量分数为8％的多乙烯基硅油和4份羟基硅油，用40份白炭黑增强，可得到拉伸强度为8．71MPa，撕裂强度为52．14kN／m的乙烯基硅橡胶。     

硅橡胶的改性研究

综述了近年来硅橡胶的改性研究,主要阐述了硅橡胶和其他橡胶共混改性,纳米SiOx改性室温硫化硅橡胶和矿物微粉增强硅橡胶性能。     

航空硅橡胶用热硫化型胶粘剂的性能研究

研究了热硫化型胶粘剂XY-931S和XY-601S的性能，试验结果表明，胶粘剂XY-931S具有较好的常温和高温粘合性能，耐热空气老化性能及耐油性能，可用于三氟丙基甲基乙烯基硅橡胶与金属的热硫化粘合；胶粘剂XY-601S具有良好的粘合性能和耐热性，在300℃下的耐热空气老化性能稳定，可用于甲基乙烯基硅橡胶和低苯基甲基乙烯基硅橡胶与金属的热硫化粘合。     

橡胶的热氧加速老化试验及寿命预测方法

简介橡胶的热氧加速老化试验和寿命预测方法。采用加速老化试验预测橡胶寿命的理论基础是时温等效原理和扩散限制氧化(DLO)模型；时间一温度叠加的理论模型常用系列试验曲线求解Arrhenius活化能．确定平移因子。，通过平移试验曲线得到任一温度下橡胶的寿命；扩散限制氧化模型通过一系列试验确定橡胶中氧气的浓度与橡胶模量的关系，再通过测定橡胶中氧气的浓度预测橡胶的寿命。     

Study on the life expectancy of storage and ageing for rubber vulcanizates

Summary In this paper the relationship of the ageing time to the tensile strength and the ultimate elongation of rubber vulcanizates was derived from the combination of ageing kinetics with the molecular theory of ultimate tensile strength of elastic networks, basing on the micro-structure model of rubber vulcanizates. According to this relation, a new simple method for determining the coefficients (α₄) of ageing time and the ageing rate constants (k ₄) of rubber vulcanizates from the data of the extension tests was proposed. The accelarated ageing experiments of Butadiene-acrylonitrile Rubber (BAR) vulcanizates were carried out at the range of temperature 70–110°C in a given period of 1–100 days, and the molecular parameters were determined by using this new method. It is shown that the experimental results are consistent to the theory.     

三元乙丙橡胶热氧老化试验与密封条寿命预测

运用热空气加速老化试验方法对塑钢窗密封条用三元乙丙橡胶进行了不同温度下的老化,并对其使用寿命进行了预测。首先建立了基于Arrhenius原理的老化寿命预测模型,然后对该数学模型进行了验证和统计分析。结果表明,模型预测结果与实验值吻合很好,相关系数大于0.99。根据预测值与试验值的偏差对预测模型进行了进一步修正,根据修正后的模型预测得到30℃下、拉断伸长率保持率在70%时,密封条的使用寿命为68.73年。