四烯丙基二苯甲烷二胺／双马来酰亚胺共聚树脂玻璃布层压板的研制

本文以Ｎ，Ｎ，Ｎ’，Ｎ’－四烯丙基二苯甲烷二胺和二苯甲烷双与来酰亚胺为主要原料合成了一类新型的耐高温双马来酰亚胺共聚树脂，并以此树脂为基体制得了玻璃布预浸料及层压板，考察了共聚树脂及玻璃布预浸料的贮存稳定性和层压板的性能，实验结果表明，共聚树脂及预浸料贮存期长，工艺性良好，层压板制备工艺幅度宽，电性能和高温力学性能优异，可作为耐高温绝缘材料和结构材料使用。     

酚醛树脂／玻璃纤维／石棉复合材料的研究

采用玻璃纤维／石棉混合增强材料来增强酚醛树脂层压板的性能。研究了不同含量的聚乙烯醇缩丁醛和邻苯二甲酸二辛脂对酚醛树脂基玻璃纤维石棉复合材料力学性能的影响。确定了合理的工艺参数。实验研究发现，邻苯二甲酸二辛酯和聚乙烯醇缩丁醛等改性剂在配方中含量的改变能较大地影响酚醛树脂层压板的力学性能。     

新型改性BMI／T300和BMI／T800复合材料性能

本文研究了新型改性BMI树脂与T300和T800）碳纤维形成的预浸料和复合材料层压板性能，并对二者进行了比较和分析，获得了具有良好力学性能的BML/T300和BML/T800复合材料体系。     

热固性聚（氨酯－酰亚胺）玻璃布层压板的制备及性能

本文以两种含不同氨酯键结构的双马来酰亚胺ＢＭＵ－Ｈ和ＢＭＵ－Ｔ作为基体树脂。考察了这种新型双马来酰亚胺树脂的固化行为和固化物的耐热性，对热固性聚（氨酯－酰亚胺）玻璃布层压板的制备与性能进行了研究，实验结构表明：合氨酯键双马来酰亚胺树脂固化温区较低，而固化物的耐热温度指数分别为２１３℃（ＢＭＵ－Ｈ）和２１０℃（ＢＭＵ－Ｔ），表现出良好的耐热性。制备的树脂溶液和玻璃布预浸料具有很好的贮存稳定性和成型加工性能，压制得的玻璃布层压板具有良好的综合性能。     

双马来酰亚胺/二烯丙基双酚A共聚树脂及其玻璃布层压板的制备和性能

用溶液法合成了双马来酰亚胺(BMI)/二烯丙基双酚A(DABPA)共聚树脂。用FTIR、~1H-NMR等方法表征了树脂的结构。DSC曲线显示该树脂的固化能与熔融法得到的基体树脂有所不同。该树脂固化后有良好的热稳定性。以该树脂为基体制备了玻璃布层压板,测试结果表明层压板具有较好的力学性能和电气性能可以作为耐高温结构材料或电绝缘材料在180～200℃长期使用。     

THEIC／三聚氰胺／酚甲醛共缩聚树脂的合成及应用

THEIC、三聚氰胺、酚甲醛共缩聚反应得到新型的热固性树脂(MPT树脂),其耐热温度指数大于200℃。以MPT树脂为基础的玻璃布层压板成型工艺易于实施,层压板具有较高的耐热性和优良的综合性能,可作为一种通用型的耐高温结构材料和F级绝缘材料使用。     

PAN／PS共混中空纤维超滤膜研究

本文将聚丙烯腈（ＰＡＮ）和聚砜（ＰＳ）材料共混，采用二甲基甲酰胺（ＤＭＦ）作溶剂，以干－湿纺丝工艺制备中空纤维超滤膜，研究了二种膜材料和溶剂的热力学性质，确定合适的共混体系，并相同共混比下共混物浓度对中空纤维超滤膜性能影响。以磷酸三乙酯（ＴＥＰ）和冰醋酸作为添加剂，分别观测其不同含量膜性能变化规律。认为磷酸三乙酯作用添加剂有一定的优越性。提高铸膜液温度，有助于增强ＰＡＮ－ＰＳ－ＤＭＦ所组成部分互溶     

聚芳醚腈砜碳布层压板和玻璃布层压板的研制

本文以２,６－二氟苯甲腈和４,４－二羟基二苯砜为主要原料合成了聚芳醚腈砜利用ＩＲ、＾１３Ｃ－ＮＭＲ和热分析等手段对其结构和热性能进行了表征。以取长醚腈砜为基体树脂采用特殊的溶液浸胶工艺,一次邓要制我含量达４５％的预浸料。制得的碳布层压板和玻璃布层压板皆具有优异的力学性能和热性能,可在１８０℃使用。     

TPU／ABS塑料合金的研制

通过熔融共混法制备了ＴＰＵ／ＡＢＳ塑料合金，并以此材料试制了塑料纬纱管。讨论了ＴＰＵ含量，共混工艺等因素对合金力学性能和形态结构的影响，结果表明，在ＴＰＵ含量为５－２０％时，所制ＴＰＵ／ＡＢＳ塑料合金具有良好的综合性能，尤其在冲击强度和耐磨性能方面都有明显改进。用此材料制造的纬纱管，经检测，各项性能均达到了各颁标准，经有关厂家初步应用认为，达到了纺机配件的使用要求。     

苎麻/苯并噁嗪层压板的制备及其阻燃改性

采用聚磷酸铵(APP)和磷氮类阻燃剂(NEWRAY911)对苎麻/苯并噁嗪树脂层压板进行阻燃改性,并通过万能材料试验机、极限氧指数(LOI)、垂直燃烧实验、热失重仪(TG)和微型燃烧量热仪(MCC)对层压板性能进行分析。实验结果表明:经过APP改性后的层压板LOI有明显的增加,但只有当APP添加量达到7%时层压板的垂直燃烧才能通过V0级,且APP过多的添加也使层压板的力学性能有较大的损伤。采用NEWRAY911阻燃改性苎麻织物不仅可以使层压板的阻燃性能得到改善,同时也减少APP的添加量,使苎麻/苯并噁嗪树脂层压板在阻燃改性的同时保持了良好的力学性能。经APP和NEWRAY911改性后的层压板明显减缓了分解速率、燃烧热释放量及释放速率,提高了热分解的残炭量。     

EVA/EPDM/IR/IR共混发泡材料的性能研究

研究了乙烯醋酸乙烯酯共聚物（ＥＶＡ）／ＥＰＤＭ／ＩＲ三元共混和ＥＶＡ／ＥＰＤＭ／ＩＲ／ＩＲ四元共混发泡材料的性能。在ＥＶＡ中混入ＥＰＤＭ可使发泡材料的拉伸强度、撕裂强度和粘合强度提高,而收缩率和压缩永久变形降低;在ＥＶＡ中混入ＩＲ除具备混入ＥＰＤＭ同样的优点外,还可提高发泡材料的柔性;ＩＲ的混入可改善发泡材料二次热压成型制品的表面清晰度。     

SO42-/MxOy型固体超强酸研究进展

SO₄^2-/M_xO_y固体超强酸具有不腐蚀设备、污染小、耐高温、对水稳定性好和可重复使用等优点。综述了SO₄^2-/M_xO_y型固体超强酸的催化机理、失活原因、改性及表征方法,并对今后SO₄^2-/M_xO_y型固体超强酸的研究方向进行了展望。     

Microwave Dielectric Properties of CaTiO3-CaAl1/2Nb1/2O3 Ceramics Doped with Li3NbO4

The microwave dielectric properties of CaTi_{1− x} (Al_1/2Nb_1/2) _x O₃ solid solutions (0.3 ≤ x ≤ 0.7) have been investigated. The sintered samples had perovskite structures similar to CaTiO₃. The substitution of Ti⁴⁺ by Al³⁺/Nb⁵⁺ improved the quality factor Q of the sintered specimens. A small addition of Li₃NbO₄ (about 1 wt%) was found to be very effective for lowering sintering temperature of ceramics from 1450–1500° to 1300°C. The composition with x = 0.5 sintered at 1300°C for 5 h revealed excellent dielectric properties, namely, a dielectric constant (ɛ_r) of 48, a Q × f value of 32 100 GHz, and a temperature coefficient of the resonant frequency (τ_f) of −2 ppm/K. Li₃NbO₄ as a sintering additive had no harmful influence on τ_f of ceramics.     

Ferromagnetism and Magnetoresistance in La0.67Sr0.33Fe0.07Mn0.93O3

A bulk ceramic sample La_0.67Sr_0.33Fe_0.07Mn_0.93O₃ (LSFMO) with a rhombohedral structure has been prepared from a coprecipitated carbonate precursor in this study. Ferromagnetism and a negative, isotropic magnetoresistance (MR) as large as 11% have been observed in a ceramic sample of LSFMO. There are two resistivity transition peaks on the resistivity versus temperature curves. The resistivity peak and MR have been related to the ferromagnetic state in LSFMO.     

Effect of V2O5 Doping on the Sintering and Dielectric Properties of M-Phase Li1+x−yNb1−x−3yTix+4yO3 Ceramics

The effect of the addition of V₂O₅ on the structure, sintering and dielectric properties of M -phase (Li_{1+ x − y} Nb_{1− x −3 y} Ti _x +4 _y )O₃ ceramics has been investigated. Homogeneous substitution of V⁵⁺ for Nb⁵⁺ was obtained in LiNb_{0.6(1− x )}V_{0.6 x} Ti_0.5O₃ for x ≤ 0.02. The addition of V₂O₅ led to a large reduction in the sintering temperature and samples with x = 0.02 could be fully densified at 900°C. The substitution of vanadia had a relatively minor adverse effect on the microwave dielectric properties of the M -phase system and the x = 0.02 ceramics had [alt epsilon]_r= 66, Q × f = 3800 at 5.6 GHz, and τ_f= 11 ppm/°C. Preliminary investigations suggest that silver metallization does not diffuse into the V₂O₅-doped M -phase ceramics at 900°C, making these materials potential candidates for low-temperature cofired ceramic (LTCC) applications.     

聚烯烃塑料用胶粘剂SBS／MMA／BA／MAA的合成与性能研究

以甲基丙烯酸（MAA）为功能单体,与SBS和甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）进行四元接枝共聚,合成了聚烯烃塑料用胶粘剂,探讨了不同溶剂、MMA／BA配比、MAA和BPO用量以及固化时间对粘接性能的影响,并对该四元接枝胶的性能与三元胶和SBS／MMA／BA／AA四元接枝胶进行了比较。结果发现：四元接枝胶性能优于三元胶,特别是与异氰酸酯配合时,剪切强度、固化速度明显提高,四元胶的优化配方是120＃汽油：甲苯：乙酸乙酯为8：1：1,MMA：BA配比3：1,MAA加入量7份,BPO用量1．5－2份（以100份SBS计）。     

BA／VAc／AN／AA共聚乳液胶粘剂的研制

介绍了一种丙烯酸丁酯／醋酸乙烯酯／丙烯腈／丙烯酸四元共聚乳液胶粘剂的制备方法,该胶具有良好的耐黄变性,可替代天然橡胶胶乳应用于EVA低发泡体与腈纶绒面布的复合。     

Electronic Structure and Bonding in Crystalline Y10[SiO4]6N2

The electronic structure and bonding of the complex ceramic crystal Y₁₀[SiO₄]₆N₂ is studied by a first-principles method. It is shown that this crystal is an insulator with a direct band gap of 1.3 eV. It has some unique properties related to the one-dimensional chain structure in the c -direction and the planar N-Y bonding in the x - y plane.     

Relaxor Behavior of the 0.9BaTiO3–0.1La(Mg1/2Ti1/2)O3 Solid Solution

Low-frequency dielectric response of air- and oxygen-sintered ceramics with the composition 0.9BaTiO₃–0.1La(Mg_1/2Ti_1/2) O₃ (0.9BT–0.1LMT) has been studied in the temperature range of 12–550 K. In comparison with pure BT, in 0.9BT–0.1LMT the dielectric permittivity maximum is shifted by almost 300 K toward lower temperatures. Both real and imaginary parts of dielectric permittivity of the solid solution, in the range 12–150 K, show a strong frequency-dependent behavior, which is typical of relaxors. On the basis of the model of exponential cluster size distribution and the Cole–Cole equation, the degree of interaction between the polar clusters was estimated. It was shown that the oxygen vacancies arising during sintering at high temperatures did not affect noticeably the relaxor properties of the material. The role of heterovalent La³⁺/Ba²⁺ and Mg²⁺/Ti⁴⁺ substitutions in the relaxor behavior formation is discussed.     

A- and B Site Cosubstituted Ba6−3xSm8+2xTi18O54Microwave Dielectric Ceramics

Tin (Sn) substitution into the B-site and Nd/Sn cosubstitution into the A- and B-sites were investigated in a Ba _{6−3 x} Sm_{8+2 x} Ti₁₈O₅₄solid solution ( x = 2/3). A small amount of tin substitution for titanium improved the temperature coefficient of resonant frequency (τ_f) but led to a decrease of the relative dielectric constant (ɛ) and the quality factor ( Qf ). The Ba_{6−3 x} Sm_{8+2 x} (Ti_{1− z} Sn_z)₁₈O₅₄-based tungsten-bronze phase became unstable for compositions with a tin content of ≥10 mol%, where BaSm₂O₄and Sm₂(Sn,Ti)₂O₇appeared, and finally, these phases became the major phases. On the other hand, Nd/Sn cosubstitution led to a good combination of high ɛ, high Qf , and near-zero τ_f. Excellent microwave dielectric properties were achieved in Ba_{6−3 x} (Sm_{1− y} Nd _y )_{8+2 x} (Ti_{1− z} Sn _z )₁₈O₅₄ceramics with y = 0.8 and z = 0.05 sintered at 1360°C for 3 h: ɛ= 82, Qf = 10 000 GHz, and calculated τ_f=+17 ppm/°C. The tolerance factor and electronegativity difference exhibited important effects on the microwave dielectric properties, especially the Qf value. A large tolerance factor and high electronegativity difference generally led to a higher Qf value.