动态热机械分析仪

this study investigates the mechanical behaviour of polyester fibres over a range of temperatures by the use of a number of experimental techniques including tensile, creep and fatigue tests.the influences of temperature on the different mechanical properties is investigated with particular emphasise on the loss of rigidity and reduction of creep and fatigue lifetimes.A precise description of the stress /strain curves of the fibres highlights the effects with respect to the glass transition temperature. The fatigue failure process is precisely detailed and changes, at high temperatures, to the classical fracture morphology observations made of single fibres and yarns provides valuable information about the interpretation of result obtained with single fibre test to fibre assemblies

研究炭黑和自拨黑料强榕噩丁辈橡肢( SSBR ) 胎面脏的抗温晴性能，井分析抗湿惰性能的影响因章. 结果量明，在一定温度和速度范围内，自提黑补强SSBR 胎面胶抗湿晴性能优于炭黑补强SSBR 胎面肢z 仅果用动在粘弹性能理征胎面肢的抗湿滑佳能是不完善的，抗湿惰性盹量温度、速度和跤料硬度等的嚣响，是润情作用和动在帖弹性能等共同作用的结果.

摘要:研究炭黑或自炭鼎补强溶噩丁荤幢胶(SSBR) 和乳罩丁苯幢胶(ESBR) 胎面肢的性能. 结果表明.SSBR 与白棋嚣的冉面作用强于ESBR ，当罪用自炭照补强时， SSBR 硫化腔的物理性能优于ESBR. 而罪用提黯补强时.SSBR硫化肢的物理性能无明显优势B 与炭黑补强SBR 硫化被相比.自炭黑补强SBR 硫化腔的抗湿滑性能按好，滚曲阻力较低，但耐磨性能辍盏，其中自炭黑补强SSBR 硫化肢的抗湿晴性能最突出.

We have investigated the dynamic mechanical behavior of two cross-linked polymer networks with very different topologies: one made of backbones randomly linked along their length; the other with fixed-length strands uniformly cross-linked at their ends. The samples were analyzed using oscillatory shear, at very small strains corresponding to the linear regime. This was carried out at a range of frequencies, and at temperatures ranging from the glass plateau, through the glass transition, and well into the rubbery region. Through the glass transition, the data obeyed the time-temperature superposition principle, and could be analyzed using WLF treatment. At higher temperatures, in the rubbery region,the storage modulus was found to deviate from this, taking a value that is independent of frequency.This value increased linearly with temperature, as expected for the entropic rubber elasticity, but with a substantial negative offset inconsistent with straightforward enthalpic effects. Conversely, the loss modulus continued to follow time-temperature superposition, decreasing with increasing temperature, and showing a power-law dependence on frequency.

We study three monodomain single-crystal nematic elastomer materials, all side-chain siloxane polymers with the same mesogenic groups but with different types of cross linking: short flexible siloxane linkage affine to the network backbone, short flexible aliphatic cross links miscible with mesogenic side-chain groups, and long segments of main-chain nematic polymer. The dynamic mechanical response of these three systems shows a characteristically universal decrease of storage modulus and a corresponding increase of loss factor. This effect of dynamic soft elasticity is strongly anisotropic, depending on the nematic director orientation. We examine the important role of the average backbone chain anisotropy , which is affected by the cross-linking geometry and contributes to the magnitude and frequency dependence of the dynamic anomaly, and discuss possible applications in mechanical damping and polarized acoustic technology.