白炭黑在NR／BR／SSBR并用胶中的应用

研究了白炭黑／炭黑填充NR／BR／SSBR并用胶的物理性能，用橡胶加工分析仪(RPA2000)分析并用胶硫化性能和动态粘弹性的变化规律。结果表明，炭黑和白炭黑总量固定，白炭黑的用量增大时，并用胶的物理性能略有下降，固特里奇压缩疲劳性能改善，并用胶的硫化速度减缓，且t90和t10的变化与白炭黑的用量呈线性关系；60℃的tan8值随白炭黑用量增大则呈下降趋势，即硫化胶的滚动阻力降低。     

稻壳源白炭黑/炭黑/天然橡胶复合材料的性能研究

试验研究稻壳源白炭黑/炭黑并用对天然橡胶硫化胶性能的影响。结果表明:当稻壳源白炭黑/炭黑用量比较高时,胶料的M_L较大,t_(10)较短,t_(90)较长,物理性能较差;当稻壳源白炭黑、炭黑用量较为均衡时,硫化胶的物理性能变化不大,动态力学性能较好;稻壳源白炭黑/炭黑用量比对硫化胶耐寒性能的影响不大;当稻壳源白炭黑/炭黑用量比为20/40和25/35时,硫化胶的综合性能较好。     

炭黑/白炭黑并用对胎侧胶性能的影响

研究炭黑/白炭黑并用对胎侧胶性能的影响。结果表明：混炼温度影响炭黑/白炭黑并用填充胶料的挤出性能和外观；炭黑/白炭黑并用填充胶料的门尼焦烧时间和t90与炭黑填充胶料相比均明显缩短，并随着白炭黑用量的增大呈延长趋势；随着炭黑/白炭黑并用体系中白炭黑用量的增大，硫化胶的100%和300%定伸应力减小，拉伸强度和拉断伸长率增大，耐臭氧老化性能明显改善，压缩疲劳温升和滞后损失减小，Payne效应呈现先减弱后增强的非线性变化趋势。     

偶联剂Si69改性白炭黑对NR/SSBR并用胶性能的影响

试验研究偶联剂Si69用量和白炭黑改性方法对白炭黑填充NR/SSBR并用胶性能的影响.结果表明,当采用直接加入法改性白炭黑时,随着偶联剂Si69用量的增大,Payne效应减弱,NR/SSBR并用胶的t10延长,t90缩短,硫化胶的物理性能提高,偶联剂Si69用量以4 5份为宜.与直接加入法改性白炭黑填充并用胶相比,预处理法改性白炭黑填充并用胶的Payne效应减弱,拉伸强度和撕裂强度增大;高温静置处理法改性白炭黑填充并用胶的定伸应力、拉伸强度和损耗模量增大.     

微晶纤维素在溶聚丁苯橡胶/顺丁橡胶并用胶中的应用

研究微晶纤维素部分替代白炭黑对溶聚丁苯橡胶(SSBR)/顺丁橡胶(BR)并用胶性能的影响。结果表明:在白炭黑或白炭黑/炭黑填充SSBR/BR并用胶中,当微晶纤维素用量不超过9份时,硫化胶的物理性能变化不大;当微晶纤维素用量超过9份时,硫化胶的物理性能下降;随着微晶纤维素用量的增大,胶料的门尼粘度总体减小,填料的网络化程度降低,Payne效应减弱,损耗因子减小。     

氯化亚锡对BR/CPE共混物自硫化的影晌

在ＢＲ／ＣＰＥ自硫化共混物中加入少量氯化亚锡（０．５－２份）能显著促进自硫化反应，增大硫化速度和交联密度，共混物凝胶含量达到９８％，进一步增大氯化亚锡用量对共混物硫化和硫化胶性能无显著影响。ＢＲ／ＣＰＥ共混物用炭黑和白炭黑作补强剂较好，补强剂用量为３０份较合适；ＣＰＥ用量较大，共混物的物理性能较好。     

纳米白炭黑对NBR性能的影响

试验研究表面改性剂品种及其用量、纳米白炭黑粒径及其用量以及纳米白炭黑／炭黑并用比对NBR硫化胶物理性能的影响。结果表明，表面改性剂对纳米白炭黑填充NBR硫化胶物理性能的影响程度大小顺序为硅烷偶联剂KH-550、钛酸酯偶联剂NDZ-201、表面活性剂ABS。用0．6份硅烷偶联剂KH～550对纳米白炭黑进行改性后，当纳米白炭黑粒径为5～15nm（用量为30份）；纳米白炭黑用量为50份（粒径为15～25nm）；纳米白炭黑／炭黑并用比为15／35（纳米白炭黑粒径为15～25nm）时，NBR硫化胶的综合物理性能最佳。     

硫黄硫化EPDM/IIR并用胶硫化特性的研究

探讨生胶并用比、硫黄用量、促进剂用量、补强剂种类和用量、软化剂用量对EPDM／IIR并用胶硫化特性的影响。结果表明，EPDM／IIR并用比增大，并用胶的t90缩短，MH增大；硫黄用量增大，并用胶的t90缩短，t90延长，MH增大；促进剂CZ用量增大对并用胶的硫化特性无明显影响；炭黑N220作补强剂的并用胶t10和t90较短，MH较大；炭黑N220用量增大，并用胶的t90延长，ML和MH增大；软化剂凡士林用量增大，并用胶的t90缩短，MH减小。     

水油环境用丁腈橡胶/氯丁橡胶共混胶性能研究

对丁腈橡胶(NBR)/氯丁橡胶(CR)并用胶在水、油环境下性能的影响因素进行研究,主要研究NBR/CR配比、硫化体系、炭黑和白炭黑对并用胶的物理性能、体积电阻率和耐水、耐油性能的影响。同时研究了硫化时间对NBR/CR并用胶性能的影响。结果表明:NBR/CR并用胶(并用比为70/30)最佳硫化体系为:氧化锌5,氧化镁6,促进剂DM0.4,硫黄2;随着CR用量的增大,NBR/CR并用胶拉伸强度和体积电阻率先增大后减小,耐油性能增强;炭黑N550填充的并用胶的综合性能最佳,且当炭黑N550用量为50份、白炭黑用量为20份时,并用胶性能最佳;最佳硫化时间为50 min。     

用正交旋转设计法探讨绿色轮胎胎面胶配方设计

用三元二次通用正交旋转设计法研究了变量偶联型Ｓ－ＳＢＲ／ＢＲ,促进剂ＤＭ／Ｄ、炭黑／白炭黑与硫化胶物理性能的关系,得到一系列变量与性能的等高图,揭示了诸因素之间的内在规律。研究表明,增大白炭黑用量及偶联型Ｓ－ＳＢＲ／ＢＲ的并用比例有利于提高胶料的抗撕裂性能,炭黑与促进剂的用量直接影响着胶料的３００％定伸应力。     

Compact Swelling in Bi1.4Pb0.6Sr2Ca2Cu3.6Oy During the Formation of High-Tc Superconducting Phase

Compact swelling in Pb-doped Bi-Sr-Ca-Cu-O superconductor has been studied by observing the effects of the size of calcined powders, volatilization of materials, and sintering of high- T _c (2223) powders. The bulk density increases at the early stage of sintering, for about 20 h, and then decreases. Densification occurs when the low- T _c (2212) phase and a liquid phase exist, whereas dedensification occurs with the formation of the 2223 phase regardless of the presence of the liquid. Gas evolution from specimens does not appear to be responsible for compact swelling. Compact swelling is explained by anisotropic growth of thin, platelike 2223 grains in random orientation. When 2223 grains grow in a preferred direction, compact swelling is suppressed.     

Synthetic routes to nanoscale BxCyNz architectures

B_xC_yN_z nanoscale materials, hybrids of h-BN and graphite, have been recently synthesised using various techniques. Here, we present the latest advances in the synthesis and characterisation of B-C-N nanotubes and nanofibres. In particular, we focus on layered BC₂N, BN, BC and CN_x systems, reviewing their production methods as well as their structural and electronic properties. These materials may find important applications in the fabrication of nanotransistors, robust nanocomposites, conducting polymers, storage components and field emission sources.     

(Bi1/2Na1/2)TiO3–Ba(Cu1/2W1/2)O3 Lead-Free Piezoelectric Ceramics

(Bi_1/2Na_1/2)TiO₃ with 0–6 mol% Ba(Cu_1/2W_1/2)O₃ (BNT-BCW), a new member of the BNT-based group, has been prepared following the conventional mixed oxide route. The compacted bodies were sintered at 1130°C for 2 h to get dense ceramics. The addition of BCW into BNT ceramics facilitated the poling process because of a reduction in leakage current. 0.995BNT·0.005BCW ceramics exhibit a relatively high piezoelectric constant ( d ₃₃= 80 × 10⁻¹² C/N) and a relatively low dielectric loss (tan δ= 1.5%). Increased amount of BCW was found to increase the dielectric constant and loss of BNT-BCW ceramics and to suppress the grain growth. During sintering, some BCW diffuses into the lattice of BNT to form a solid solution and some remains on the grain boundaries.     

Structure Evolution from Pb(Mg1/3Nb2/3)O3 to La(Mg2/3Nb1/3)O3

The crystal structure of lanthanum-modified lead magnesium niobates having composition (Pb_{1− x} La _x ) (Mg_{(1+ x )/3}-Nb_{(2− x )/3})O₃ with X = 0 to 1 was investigated by X-ray powder diffraction. It was found that the fundamental reflections from perovskite structure remain in the whole range of composition. The superlattice reflections from the A(B'_1/2-B"_1/2)O₃ ordered structure are also well preserved for La content greater than 50 at.%; however, a series of extra peaks of mixing indices appears, with intensities gradually enhanced with the increase of La content. For the complete substitution of Pb by La, a splitting of some reflections can be observed in the diffraction pattern. The results indicate that the crystal structure evolves continuously with the La content, from disordered cubic perovskite of space group Pm 3 m for X = 0, to ordered cubic perovskite of space group Fm 3 m for X = 0.5, distorted cubic perovskite of space group Pa 3 for 0.5 < X < 0.9, and finally to a rhombohedral perovskite, possibly belonging to the space group R 3 , for X ≥ 0.9. In the evolution of structure, a linear reduction of the lattice constant of the perovskite cell from 4.048 to 3.964 Å was observed.     

炭黑/煤矸石/碳纳米管复合填料体系对天然橡胶性能的影响研究*

利用硝酸氧化法对碳纳米管(CNTs)进行纯化,并用环氧天然橡胶(ENR)进行改性处理。结合胶质量分数测定结果表明, ENR用量15%(质量)时效果最佳。采用胶乳凝聚法制备CNTs/天然橡胶(NR)母料。煤矸石粉(CG)经高温煅烧和表面改性处理。 将CNTs/天然橡胶(NR)母料、CG和炭黑(CB)通过机械混炼法与天然橡胶及配合剂混合,制备CB/CG/CNTs/NR复合材料,并对复合材料进行硫化特性及物理机械性能。结果表明： CNTs延迟硫化效应明显;相比炭黑,CG对硫化具有促进作用。硫化特性和甲苯溶胀法测定结果表明,在填料份数相同的条件下,单独由CB填充的NR有最大的交联密度,CNTs对交联密度影响不明显。物理机械性能测试结果表明,当CG：CB：CNTs=17.5:16.5:1(Phr)时,NR硫化胶的300%定伸应力和扯断伸长率明显高于单独由CB填充NR,而拉伸强度与之接近,复合填料样填充NR具有较好的综合性能。扫描电镜测试结果表明,复合填料在NR基体中分布均匀。     

Dielectric-State Analysis in Solid-Solution Pb(Yb1/2Ta1/2)O3–Pb(Lu1/2Nb1/2)O3

The structure and temperature dependence of complex lead perovskite dielectrics were investigated for the system (1 − x )Pb(Yb_1/2Ta_1/2)O₃– x Pb(Lu_1/2Nb_1/2)O₃. Superlattice reflections for the compositions 0.8 < x < 1.0 were observed by X-ray diffractometry, and the temperature-composition dielectric-state diagram was determined. In the present study, the disordered middle composition, with 0.2 < x < 0.8, showed a diffuse paraelectric–ferroelectric phase transition, whereas the ordered end compositions, with 0 ≤ x < 0.2 and 0.8 < x ≤ 1.0, revealed successive sharp paraelectric–antiferroelectric and weak antiferroelectric–ferroelectric phase transitions. The dielectric state was confirmed by examining the variation of polarization ( P ) with electric field ( E ).