泡沫陶瓷制作工艺探讨

详细探讨了用软质泡沫母体浸渍陶瓷料浆来制作泡沫陶瓷的具体工艺和成孔机理，从而为泡沫陶瓷生产与应用打下了基础。研制的Ａｌ２Ｏ３泡沫陶瓷网格数达８个／ｃｍ，气孔率达到８０％，强度达到２．５ＭＰａ，其性能已达到应用指标。     

聚氨酯半硬泡的研制

开发了以自产的高活性聚醚和聚合物多元醇为基础的聚氨酯半硬泡,讨论了聚醚、催化剂、交联剂等因素对泡沫性能的影响。制成的半硬泡性能为：密度１５６．５ｋｇ／ｍ~３,拉伸强度０．２５ＭＰａ,２５％压缩负荷０．１３２ ＭＰａ,断裂伸长率４０．８％。     

低水泥刚玉浇注料及干式振动料在有芯工频感应炉上的应用

低水泥刚玉浇注料中加入Ａｌ２Ｏ３、ＳｉＯ２超细微粉、表面活化剂及改性剂后，体积密度≥３．００ｇ／ｃｍ３，１６００℃，５ｈ烧后冷态抗折强度≥１５ＭＰａ。在有芯工频感应炉上使用，寿命达三年以上。ＭｇＯ－Ａｌ２Ｏ３质干式振动料具有合适的烧结温度和力学强度。１６００℃，５ｈ烧后冷态抗折强度≥３．０ＭＰａ，冷态耐压强度≥１５．０ＭＰａ。在７００ｋＷ感应器上使用，寿命达半年以上，在其它感应器上使用，寿命１—２年。     

湿化学法制备微晶（Y,Mg）—PSZ／MgAl2O4陶瓷的研究

研究了用湿化学法制备Ｙ２Ｏ３－ＭｇＯ－ＺｒＯ２－Ａｌ２Ｏ３四元系超细粉的工艺技术，探讨了包裹沉和包裹沉淀－乙酸镁混合两种制备工艺组成对微晶ＰＳＺ材料结构、性能的影响。经１１００℃适当时间的热处理获得了在ｃ－ＺｒＯ２中具有ｔ－ＺｒＯ２梭形析出体的微晶ＰＳＺ复相陶瓷，其室温强度达８００ＭＰａ，断裂韧笥在１４ＭＰａ，Ｍ＾１／２左右，１０００℃下高温强度可达４５８ＭＰａ。     

聚丙烯酸系铸造粘结剂生产工艺研究

腈纶废料经高温、高压可催化水解成一种粘度在２—５Ｐａ·ｓ之间，ｐＨ为７—８，并具有一定粘结强度的水溶性溶液。水解条件为浴比１：６，温度１８０—２００℃，压力１．０—１．５ＭＰａ，催化剂ＸＢ２％。此水解液用于混砂制芯具有优良的铸造性能，拉伸强度可达２．２ＭＰａ以上，湿压强度为０．０１２ＭＰａ，是一种性能优良的粘结剂。     

湿化学法制备微晶（Y，Mg）－PSZ／MgAl_2O_4陶瓷的研究

研究了用湿化学法制备Ｙ_２Ｏ_３－ＭｇＯ－ＺｒＯ_２－Ａｌ_２Ｏ_３四元系超细粉末的工艺技术，探讨了包裹沉淀和包裹沉淀－乙酸镁混合两种制备工艺及组成对微晶ＰＳＺ材料结构、性能的影响。经１１００℃适当时间的热处理获得了在ｃ－ＺｒＯ_２中具有ｔ－ＺｒＯ_２梭形析出体的微晶ＰＳＺ复相陶瓷，其室温强度达８００ＭＰａ，断裂韧性在１４ＭＰａ·ｍ１／２左右，１０００℃下高温强度可达４５８ＭＰａ。     

气相生长炭纤维增强的C／C各向同性复合材料

用冷压成型和热压成型工艺制备了以气相生长炭纤维为增强剂的Ｃ／Ｃ各向同性复合材料。冷压成型的复合材料炭化处理后尺寸膨胀，密度只能１．３８ｇ／ｃｍ~３，但其弯曲强度达３４ＭＰａ，弹性模量达２．２×１０~４ＭＰａ，比密度为１．７５ｇ／ｃｍ~３的核石墨分别高５０～１００％和２００～３００％，热压成型的复合材料弯曲强度达５７ＭＰａ，弹性模量５３×１０~４ＭＰａ，断裂韧性４．７２ＭＰａｍ~（１／２），其性能远高于核石墨。     

浮法玻璃锡槽底用高强度高密度大砖的研制与应用

这种浮法玻璃锡槽底砖是用粘土熟料、莫来石细粉、氧化物超细粉和硬化剂组成的自硬性泥料制作的。采用振动成型，１２５０－１３００℃烧成。理化性能：ＳｉＯ２４５％，Ａｌ２Ｏ３４８．３８％；显气孔率１５．１％，体积密度２．３８ｇ／ｃｍ３，耐压强度７５ＭＰａ，抗折强度１３ＭＰａ，氢扩散３５０Ｐａ。所有这些性能均优于国内外同类产品指标。     

AIN在SiC—AIN—Y2O3复相陶瓷中的作用

氮化铝相在ＳｉＣ－ＡＩＮ－Ｙ２Ｏ３复相陶瓷中起着至关重要的作用。在２０５０℃高温时，ＡＩＮ颗粒表面发生固相蒸发现象，并聚集到ＳｉＣ颗粒周围最终形成固溶体，改善了ＳｉＣ颗粒周围最终形成固溶体，改善了ＳｉＣ陶瓷的晶界结构，使该复相材料具有良好的机械性能，其室温抗折强度为６１０ＭＰａ，这一强度可持续至１４００℃高温，断裂韧性达到８．１ＭＰａ．ｍ＾１／２。     

阻燃增强尼龙6的研制

以芳香族溴化物、硼酸盐、含氮杂环化物组成复合阻燃体系，以玻璃纤维为增强剂，经高速混俣和双螺杆挤出造粒研制成阻燃增强尼龙６，其阻燃性能达到ＦＶ－０级，缺口冲击强度 ２０ｋＪ／ｍ＾３，拉伸强度１３８ＭＰａ，弯曲强度２４２ＭＰａ，还研究了阻增强尼龙６的流变性能，考察了复合阻燃体系配比、玻璃２纤维含量、尼龙６相对粘度、工艺条件对阻燃增强尼龙６性能的影响。     

Structure and properties of AN/MAA/AM copolymer foam plastics

In this article, acrylonitrile (AN)/methacrylic acid (MAA)/acrylamide (AM) copolymer foam was prepared. DSC, TG and FTIR were adopted to analyze the chemical reactions in AN/MAA/AM copolymer foam, and confirm its molecule structure. SEM was employed to observe its cell structure, and the calculational method of resin distribution was founded basing on dodecahedron cell structural model. At last, its mechanical properties and thermal resistance were tested. The results indicate that cyclization reactions occur between adjacent AN/MAA units and MAA/AM units. Six-member imide rings, residuary MAA and AN units exist in main chains, and imide groups crosslink the chains. AN/MAA/AM copolymer foam has flat and closed cell walls with a high cell wall volume ratio. Cell wall volume ratios with the density of 32 kg/m³, 54 kg/m³ and 75 kg/m³ are 76%, 57% and 50% respectively. Because of rigid molecule structure and ideal cell structure, AN/MAA/AM copolymer foam possesses excellent mechanical properties and thermal resistance. As the densities are 32 kg/m³, 54 kg/m³ and 75 kg/m³, tensile strength are 1.00 MPa, 1.85 MPa and 2.30 MPa, compressive strength are 0.40 MPa, 1.00 MPa and 1.72 MPa, and shear strength are 0.45 MPa, 0.86 MPa and 1.29 MPa respectively. Heat distortion temperature of the copolymer foam is higher than 180 °C.     

Generation of low‐density high‐performance poly(arylene ether sulfone) foams using a benign processing technique

In this study, a benign process was used to successfully produce low density foam from poly(arylene ether sulfone) (PAES). Both carbon dioxide (CO₂) and water as well as nitrogen and water were used as physical blowing agents in a one‐step batch process. A large amount of blowing agents (up to 7.5%) was able to diffuse into the PAES resin in a 2‐h saturation time. Utilizing water and CO₂ as the blowing agents yielded foam with better properties than nitrogen and water because both the water and CO₂ are plasticizers for the PAES resin. PAES foam produced from CO₂ and water had a large reduction in foam density (～80%) and a cell size of ～50 μm, while maintaining a primarily closed cell structure. The small cell size and closed cell structure enhanced the mechanical properties of the foam when compared with the PAES foam produced from nitrogen and water. The tensile, compressive, and notched izod impact properties of the PAES foams were examined, and the compressive properties were compared to commercially available structural foams. With reduced compression strength of 39 MPa and reduced compression modulus of 913 MPa, the PAES foam is comparable to polyetherimide and poly(vinylchloride) structural foams. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers     

液体NBR增韧酚醛泡沫研究

研究了液体丁腈橡胶(LNBR)对酚醛泡沫的增韧效果.通过红外光谱、万能试验机、热重分析仪等测试手段对改性后酚醛泡沫特征官能团的存在、力学性能、耐热性能分别进行表征分析.实验结果表明:共聚物存在LN-BR与PF(酚醛树脂) 的结构单元;当改性剂用量为0.6份(占树脂总质量)时,泡沫塑料的压缩强度由原来的0.105 MPa提高到0.336 MPa,证明LNBR对PF泡沫有显著的增韧作用;泡沫在802 ℃时失重44%,说明泡沫经改性后具有良好的耐热性能且未影响其热稳定性.     

轨道车辆泡沫夹芯中顶板夹层设计与优化

轨道车辆的生产中大量采用平板铝合金或玻璃钢板件,产品质量偏重且材料容易出现下垂,满足不了车体轻量化与美观的需求.通过仿真与试验结合的方式研究酚醛泡沫、聚对苯二甲酸乙二醇酯(PET)泡沫、聚氯乙烯(PVC)泡沫夹芯中的面板厚度、芯材模量对中顶板质量及下垂挠度的影响,测试了不同复合夹芯板的平拉强度、平压强度以及弯曲强度.结...     

建筑保温材料用酚醛泡沫的改性与性能

在苯酚、甲醛的聚合体系中添加硼酸和碳纤维,通过正己烷发泡剂的方法制备了硼改性和碳纤维复合的酚醛泡沫材料。利用傅立叶变换红外光谱仪、微控电子万能试验仪、冲击试验机、热失重分析仪等对酚醛泡沫的结构特性、力学性能和抗氧化性能进行表征与分析。研究结果表明,当表面活性剂吐温80的用量为4%~6%,发泡剂正己烷的用量为5%左右时,酚醛泡沫具有均一的孔结构和较高的表观密度;在反应体系中添加硼酸和碳纤维可改善酚醛泡沫材料的性能,添加7.2%含量的硼使得酚醛树脂具有最高的抗氧化性能,添加30%含量的碳纤维增强了酚醛泡沫材料的弯曲强度和冲击强度,其值分别达到132 MPa和52 k J/m2。     

The effect of wet foam stability on the microstructure and strength of porous ceramics

Wet foam stability is of prime importance in fabricating porous ceramics with the desired microstructure and mechanical properties. In this research, wet foams were fabricated via direct foaming after separately adding an anionic surfactant (TLS) and a cationic surfactant (DTAC) into alumina slurries with a copolymer of isobutylene and maleic anhydride (PIBM) as both the dispersant and the gelling agent. The foam stability was evaluated by a stability analyzer. The bubble size rapidly increased in the wet foam with TLS as the foam stabilizer and many large bubbles appeared within 60 min. The wet foam containing DTAC was very stable. Cationic DTAC increased the hydrophobicity of alumina particles by interacting with the anionic PIBM adsorbed on the particles. The hydrophobically modified particles acted as the foam stabilizer and enhanced the wet foam stability. Furthermore, the fast gelling speed of the slurry containing DTAC also enhanced the wet foam stability. The average cell size of the ceramic with 82.9% porosity from the wet foam with TLS was 188 µm and the compressive strength was 9.7 MPa. The counterparts from the wet foam with DTAC were 54 µm of average cell size and 18.1 MPa of compressive strength. The superior stability of wet foam brought about a smaller cell size and higher strength of the resultant ceramic.     

低酸脲醛树脂泡沫材料的制备及性能研究

通过在脲醛树脂(UF)常温发泡过程中引入除酸剂,制备了一种低酸UF泡沫材料,并研究了除酸剂对该泡沫材料性能的影响。结果表明:添加除酸剂之后,泡沫材料的pH值由初期的3.4升至6.0以上,泡沫材料的压缩强度由初期的0.193 MPa降至0.176 MPa,而未添加除酸剂的泡沫材料的压缩强度由0.188 MPa大幅下降至0.122 MPa;另外,除酸剂的添加对泡沫材料的氧指数没有影响,泡沫材料开始出现老化开裂的时间由27 d增至180 d以上。     

PMI泡沫材料的制备及性能研究

采用偶氮二异庚腈(ABVN)为引发剂,尿素/甲酰胺为复合发泡剂制备了一种高性能聚甲基丙烯酰亚胺(PMI)泡沫材料。重点考察了不同配比的混合发泡剂用量对PMI泡沫材料性能的影响。结果表明:通过改变两种发泡剂的用量可以获得泡孔均匀且密度为38.39⁷5.99 kg/m3的PMI泡沫材料,而PMI泡沫的力学性能和热性能与泡沫密度呈正相关。当尿素和甲酰胺的用量都为1 phr时,所得PMI泡沫材料具有最佳综合性能,其拉伸强度和压缩强度分别为2.0 MPa和1.42 MPa,玻璃化转变温度(Tg)为217.7℃。     

Microstructure and Properties of Microcellular Poly (phenylene sulfide) Foams by Mucell Injection Molding

A series of microcellular poly (phenylene sulfide) (PPS) foams were prepared by Mucell injection molding. The cell structure, mechanical properties, crystallization behavior and dielectric property of microcellular PPS foams were systemically investigated. The results showed that the longer the length of flow passage of injection mold, the larger cell size of microcellular PPS foams. The injection parameter of shot size played an important role in relative density of microcellular PPS foams. When the relative density of microcellular PPS foam reached to 0.658, the tensile strength, flexural strength and impact strength of PPS foam materials achieved 10.82 MPa, 52.99 MPa and 0.305 J/cm², respectively. Meanwhile, with the relative density decreasing, the dielectric constant of PPS foam materials reduced, while the volume resistivity of its uprated.     

A graphite foam reinforced by graphite particles

Graphite foam was obtained after carbonization and graphitization of a pitch foam formed by the pyrolysis of coal tar based mesophase pitch mixed with graphite particles in a high pressure and temperature chamber. The graphite foam possessed high mechanical strength and exceptional thermal conductivity after adding the graphite particles. Experimental results showed that the thermal conductivity of modified graphite foam reached 110 W/m K, and its compressive strength increased from 3.7 MPa to 12.5 MPa with the addition of 5 wt% graphite particles. Through the microscopic observation, it was also found that fewer micro-cracks were formed in the cell wall of the modified foam as compared with pure graphite foam. The graphitization degree of modified foam reached 84.9% and the ligament of graphite foam exhibited high alignment after carbonization at 1200 °C for 3 h and graphitization at 3000 °C for 10 min.