CaCO3在硼酸盐中的热分解行为及其 对熔体泡沫化的影响

以Na2B4O7熔体模拟冶金炉渣,提出了CaCO3在熔渣中热分解的一种数学模型.实验证明, CaCO3粒度变化和熔渣中CaO含量变化对内生气源发泡过程的影响均与熔渣中CaCO3的分解行为有关.因此,吹气法测定的泡沫化指数Σ不能用于评价因内生气源引起的熔渣泡沫化稳定性.     

镍渣基泡沫玻璃的制备及其性能研究

以镍渣和废玻璃作为主要原料,使用Na2CO3为发泡剂,采用模具装填法来烧制泡沫玻璃.研究了镍渣的掺量、发泡剂掺量、发泡温度和发泡时间对泡沫玻璃的气孔结构和相关力学性能的影响.研究表明:镍渣掺量减少,Na2CO3掺量增加和发泡温度的升高,均会降低泡沫玻璃的体积密度,提高样品的平均气孔直径;镍渣掺量对泡沫玻璃的组成成分和晶体种类没有明显的影响;以20%镍渣和80%玻璃粉为主料,5%~7%Na2CO3为发泡剂,在发泡温度870 ℃下保温60 min,可以制备出气孔率为85.14%,体积密度为0.3715 g/cm3,抗折强度为2.062 MPa,平均气孔直径在3.13 mm的镍渣基泡沫玻璃.     

尿素衍生物对硅橡胶海绵性能的影响

以硅橡胶海绵的孔隙率、口模膨胀率、密度和硬度为测评参数，研究了尿素衍生物及其与氧化锌并用作发泡助剂对以发泡剂H发泡的硅橡胶海绵性能的影响。结果显示：在用发泡剂H制备硅橡胶海绵中，尿素衍生物作发泡助剂可有效提高发泡效果，当其用量为0．3份时．硅橡胶海绵的孔隙率达到70%，口模膨胀率达到325％，其密度为0.33g／cm^3，硬度为22；当以尿素衍生物为第一发泡助剂，ZnO为第二发泡助剂时，发泡效果进一步改善，当ZnO用量为0.6份时，硅橡胶海绵的孔隙率达到75％，口模膨胀率达到400%，其密度为0.31g／cm^3，硬度为22，且质地均匀美观，泡孔结构更为理想。SIEM电镜分析表明，当发泡剂H与氧化锌配合尿素衍生物并用时，可得到较理想的硅橡胶海绵。     

大型模胎用硬质聚氨酯泡沫塑料的制备研究

研究了大型模胎用硬质聚氨酯泡沫塑料的制备方法,考察了催化剂用量、匀泡剂用量、物理发泡剂用量、化学发泡剂、模具压力、后处理温度等对硬质聚氨酯泡沫塑料泡体结构和性能的影响。结果表明,可以通过控制催化剂三乙醇胺和有机锡的用量配比来调节发泡和凝胶速率,匀泡剂用量、物理发泡剂用量、化学发泡剂、模具压力、后处理温度等均能对泡体结构和性能产生影响。     

碳酸钙对PVC低发泡板材成型的影响

探讨碳酸钙在PVC低发泡板挤出加工中,对发泡效果、加工性能及发泡板材料性能等的影响。试验结果表明:碳酸钙的粒径2μm以下,其质量与PVC的质量比为3%~7%时,发泡效果和泡孔质量最佳,发泡制品强度最好。     

Chemically foaming of biodegradable poly(propylene carbonate) derived from carbon dioxide and propylene oxide

A composite chemical blowing agent PU8, composed of azodiformamide (AC), N,N′‐dinitroso pentamethylene tetramine (H) and other chemicals, was used to prepare the poly(propylene carbonate) foam material. The decomposition behavior of the blowing agent was investigated. The effect of blowing agent content and the foaming condition on the foaming of poly(propylene carbonate) was studied in detail. The results suggested that 10 phr PU8 is the optimum formulation to afford a desired poly(propylene carbonate) foam. The morphologies and compression strength of the poly(propylene carbonate) foam were studied using a scanning electron microscope and tensile tester, respectively. The foam with a blowing ratio of 16 can be obtained under an optimum foaming condition at 160°C for 30 min. POLYM. ENG. SCI. 46:153–159, 2006. © 2005 Society of Plastics Engineers     

浅色CM发泡体的性能研究

考察了常用型活性剂ZnO,硬脂酸锌（ZnSt）,硫化剂DCP,硫化助剂PDM,CAMV,TCHC,双—2,5及白炭黑用量对橡胶型氯化聚乙烯（CM）发泡性能的影响。结果表明,ZnO/ZnSt用量为2份/4份时,偶氮二甲酰胺（AC）峰值分解温度为186.8℃,分解效率较高,与橡胶基体硫化匹配较好;DCP用量为2.5份时,硫化胶拉伸强度相对较高;并用TCHC后,试样具有较高拉伸强度和发泡倍率;白炭黑用量为30份时,泡孔尺寸相对较小且分布均匀,拉伸强度较高。     

三次采油用泡沫剂性能评价研究

介绍了三次采油泡沫复合驱用泡沫剂性能及评价方法,研究了泡沫形成的条件,起泡剂的发泡作用及泡沫稳定性影响因素。通过对泡沫剂与地层水的配伍性、起泡能力和半衰期,以及阻力因子、封堵能力等动态研究,建立了泡沫剂系统评价方法,为今后相关研究提供技术支持。     

ABS微孔发泡材料气体扩散行为分析

采用化学交联模压法制备了丙烯腈-苯乙烯-丁二烯共聚物(ABS)微孔发泡材料,研究了发泡温度、发泡压力及发泡时间对ABS微孔发泡材料气体的扩散行为及泡孔结构的影响,结果表明:气体吸收量随着发泡温度、发泡压力和发泡时间的增加,先增大后减小;随着气体吸收量的增加,制品的泡孔尺寸逐渐减小,泡孔密度逐渐增大,增加气体吸收量有利于提高发泡效果。当发泡温度为170℃、发泡压力为10 MPa、发泡时间为12min时,泡孔密度约为2.87×108个/cm3,可满足工业上微孔发泡材料泡孔密度的要求。     

A Novel Preparation Method for Foamed Silica Ceramics by Sol-Gel Reaction and Mechanical Foaming

A simple method for obtaining silica foam has been developed by combining sol-gel reaction and mechanical foaming without added organic pore formers, in order to reduce generation of CO₂ and harmful gases by decomposition of the organic compounds. The silica foam was prepared by mechanically foaming the silica sol and controlling the viscosity change and gelling. The gelation time of the silica sol can be varied from 10 minutes to 3 hours by changing the pH, temperature and concentration of the surfactant added as a foam stabilizer. The dried silica gel foam was calcined at 600°C then fired at 1000°C to obtain sintered silica foam. The porosity and average pore size of the silica foam was 84% and 140 m, respectively. The bending strength and gas permeability of the sintered silica foam was 2.4 MPa and 9.4 × 10^–11 m², respectively.     

Effect of Viscosity on Preparation of Foamed Silica Ceramics by a Rapid Gelation Foaming Method

An environmentally benign preparation method for silica foam (the rapid gelation foaming method) was developed by combining sol-gel reactions and mechanical foaming without using organic polymers or monomers, in order to generate less CO₂ and harmful gases from the decomposition of organic compounds contained in the raw material. The viscosity of the silica sol during foaming affects the porous properties of the silica foam, i.e. the porosity and average pore size decrease with increasing viscosity. The pore structure of the silica foams depend on the viscosity of silica sol, two types of pore structure being formed. An open-pore structure is obtained by foaming low-viscosity sols, while a closed-pore structure is obtained by foaming high-viscosity sols. Since the viscosity of the silica sol affects the stability and foaming ability of the foam, the porous properties of the product can be controlled by controlling the viscosity of the silica during foaming.     

聚氨脂泡沫塑料零ODP发泡剂进展

简述了聚氨脂泡沫塑料几类没有臭氧消耗潜值（ＯＤＰ）发泡剂的应用研究进展，其中包括氢氟烃、戊烷、全水发泡和液态二氧化碳等。     

低密度碱矿渣发泡混凝土的制备及基本力学性能

采用化学发泡方法,以双氧水作为发泡剂,水玻璃作为激发剂,研究了激发剂初始温度、催化剂掺量、稳泡剂种类、孔结构对碱矿渣发泡混凝土基本力学性能的影响。结果表明,通过调控激发剂初始温度和催化剂掺量可以使气体的产生速率和浆体的凝结硬化达到一个较好的平衡,配合加入合适的稳泡剂能成功制备出密度约为250 kg/m³且内部结构良好的碱矿渣发泡混凝土。对比不同稳泡剂制备的同一密度等级下碱矿渣发泡混凝土的抗压强度,发现植物蛋白作稳泡剂制备碱矿渣发泡混凝土的性能最好。     

酚醛泡沫塑料的研制及应用

苯酚与甲醛在碱性条件下经加成，缩合制得可发性酚醛性脂，该树脂和表面活性剂，发泡剂，固化剂－起发泡即得酚醛泡沫塑料，实验确定了适宜的合成工艺及发泡工艺条件，产品性能。     

Microcellular thin PET sheet foam preparation by compression molding

This study has created a new way of microcellullar processing PET thin sheet foam using a conventional hydraulic press by compression molding and by setting the temperature of press plates differently. Comparing this study with our previous work, the emphasis is on the difference of plate temperature. The nonisothermal condition is used to control the foaming agent decomposition to lead to more uniform cell size microcellular foam. A variety of cell sizes, cell densities, and relative densities are obtained as a consequence of the different foaming temperature, time, pressure, and foaming agent content via isothermal and nonisothermal conditions. The effect of isothermal and nonisothermal foaming on the cell size, cells density, and relative density has been discussed. The electrical properties of the microcellular poly(ethylene terephthalate) (PET) samples prepared in nonisothermal foaming have been investigated. The experimental results show that the microcellular PET foam has lower dielectric constant and dielectric loss and higher electric resistivity than unfoamed PET. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1698–1704, 2004     

填料和增塑剂对CM/EPDM发泡材料性能的影响

以CM/EPDM并用胶为基材制得发泡材料,研究了不同填料和增塑剂对发泡材料性能的影响。结果表明,添加碳酸钙和纳米碳酸钙均可制得泡孔均匀、力学性能优良的发泡材料;碳酸钙用量为20～30份且DOP用量为20份时,发泡材料硫化速率和发泡剂分解速率匹配较好,密度小,发泡倍率高,力学性能好;DOP/石蜡油并用且随石蜡油用量的增加,发泡材料发泡倍率提高,密度减小。     

Foaming and chain extension of completely biodegradable poly(propylene carbonate) using DPT as blowing agent

Completely biodegradable foams of poly(propylene carbonate) (PPC) derived from carbon dioxide and propylene oxide were fabricated using N, N′-dinitroso pentamethylene tetramine (DPT) as chemical blowing agent, and urea as the activator to lower the decomposition temperature of DPT. Thermal decomposition behavior and gas evolution behavior of the DPT composite with various urea to DPT ratios were investigated to optimize the composition of the blowing agent. The formulation of blowing agent mixture and foaming condition, the foam morphologies, the molecular weight change, as well as the mechanical properties of produced PPC foams were studied extensively. The experimental results demonstrated that the greatest blowing ratio of 14.8 can be afforded in case 12 phr blowing agent was used at 170 °C for 30 min. Gel permeation chromatography (GPC) and thermal analysis revealed that DPT acted as both chain-extension agent and blowing agent for PPC matrix. The molecular weight of PPC subjected to foaming increased by 76%. The foamed PPC exhibited superior mechanical properties and can be used as packaging material for many practical applications.     

EFFECT OF OPERATING CONDITIONS ON GAS HOLDUP IN SLURRY BUBBLE COLUMNS WITH A FOAMING LIQUID

This work presents experimental data on gas holdup in slurry bubble columns with a foaming liquid. The effects of solids concentration, solid particle size, superficial phase velocities and column dimensions on the gas holdup are analyzed. At low superficial gas velocities (less than 4cm/s), for which the liquid does not foam, the presence of solids with small particle size does not affect the gas holdup whereas solids with large particle size induce foam formation and thus their presence increases the gas holdup. In the foaming regime, an increase of solids concentration decreases the gas holdup. The operating mode has a strong effect on the gas holdup: the semi-batch operating mode (stagnant liquid-solid suspension) increases the ability of the liquid to foam with respect to the continuous mode. Regarding the effect of column dimensions, the results presented show that the height of the bubble column does not affect at an appreciable extent the gas holdup in the range 6 < LID < 12. At high gas velocities (greater than 6 cm/s) the gas holdups obtained in a 30 cm-internal diameter column are the same as those measured in a 10 cm-internal diameter column.     

动态发泡工艺参数对PS微孔塑料泡孔结构的影响

以超临界CO2为发泡剂,用振动诱导发泡模拟装置研究了微孔塑料动态成型过程中气体饱和压力、压力释放速率、温度、气体饱和时间、稳态剪切速率、振动等工艺参数对聚苯乙烯（PS）微孔塑料泡孔结构的影响。研究发现,PS微孔塑料试样的泡孔结构随着气体饱和压力和压力释放速率的提高而得到改善,而温度、气体饱和时间、稳态剪切速率则存在一个最佳的操作范围,在此范围内制得的PS微孔塑料试样泡孔密度最大,泡孔尺寸最小。在稳态剪切速率一定的情况下,通过施加振动可以进一步改善泡孔结构．     

不同聚丙烯发泡体系的挤出发泡行为研究

通过热失重行为研究了不同升温速率对吸热型发泡剂（HP40P）和放热型发泡剂（AC）分解行为的影响；考察了线形聚丙烯（LPP）和长链支化聚丙烯（LCBPP）共混体系（LPP／LCBPP）的挤出发泡行为；制备了LPP／纳米黏土复合材料，并对其进行了挤出发泡研究。结果表明，吸热型发泡剂的分解区间较宽，分解过程平稳，可以作为聚丙烯挤出发泡很好的发泡剂，但需要通过提高螺杆转速来抑制分解过程中的气体损失；LPP／LCBPP／HP40P是良好的聚丙烯挤出发泡体系，可以得到泡孔直径100μm左右、泡孔密度接近106个／cm^2的聚丙烯挤出发泡材料；LPP／纳米黏土复合材料的挤出发泡中并未发生严重的气泡破裂和塌陷现象。动态流变性能研究结果表明该材料表现出很好的熔体弹性，可以作为聚丙烯挤出发泡的良好发泡体系。