微波连续硫化EPDM微孔垫板的研制

介绍了微波连续硫化EPDM微孔垫板的研制过程及其生产工艺,研究了胶料门尼粘度对其挤出性能的影响,补强体系与发泡体系对微孔垫板性能的影响,并确定了最终生产工艺条件。结果表明,采用微波连续硫化工艺生产的EPDM微孔垫板可满足性能及使用要求;相比于传统模压生产法,微波连续硫化法具有高效、节能、操作简单和劳动强度低等特点。     

硫化工艺对EPDM微孔橡胶垫板动静刚度比的影响

研究了硫化三要素及填胶量对EPDM微孔橡胶垫板动静刚度比的影响。结果表明,硫化温度、硫化时间以及硫化压力对橡胶垫板动静刚度比的影响是通过橡胶发泡倍率的变化来体现的,即发泡倍率越大,动静刚度比越小;密度相当时,孔径越小且孔壁越薄,孔数越多,动静刚度比越小。     

热硫化型硅橡胶海绵胶料发泡压力曲线的探讨

利用MDR-2000型硫化仪研究了硅橡胶海绵胶料的发泡压力曲线。如果表明：以发泡剂H和尿素作为发泡体系,以过氧化二苯甲酰作为硫化剂时,发泡压力经过取大值后达到平稳状态。说明发泡-硫化体系是匹配的。发泡剂H的最佳用量为6.5份,发泡-硫化的合适温度为150～160℃。     

三元乙丙橡胶发泡性能的研究

本试验通过研究不同硫化体系、温度下胶料的性能及发泡效果,来研究不同三元乙丙橡胶(EPDM)的发泡性能。结果发现以9090、9950为主体材料的快速硫化体系胶料物理机械性能和发泡效果好于常规硫化体系的胶料,其发泡工艺最好在较高温度下进行。以9046为主体材料的常规硫化体系胶料发泡效果好于快速硫化体系的胶料,发泡最好在较低温度下进行。而以4045为主体材料的胶料不适合制作发泡橡胶制品。     

低密度、高硬度发泡皮鞋外底的研制

以进口热塑性1,2-聚丁二烯、国产BR和NR为主体材料,有机发泡剂和白炭黑等为配合剂,研制低密度、高硬度发泡皮鞋外底。试验结果表明,采用普通硫黄硫化体系以及一段硫化加中途松模排气的硫化方法,制得的发泡皮鞋外底密度为0·93Mg·m-3、邵尔A型硬度为91度、收缩率为1·2%,符合质量指标要求。     

常压充模法发泡橡胶制品的研制

以天然橡胶为基材研究了常压充模法发泡橡胶制品的配方和生产工艺，通过调整发泡体系和硫化体系，采用常压、热空气硫化方法，制得表面光滑、手感好、弹性好的发泡橡胶厚制品。     

低温乳液技术合成丁腈橡胶及其性能研究(四)混炼胶部分

本文使用化工厂设备,通过低温乳液合成技术成功制备了四种合成丁腈橡胶,并且研究了在ASTM标准配方下NBR混炼橡胶的硫化性能和力学拉伸行为,同时使用密炼机和开炼机制备了NBR/PVC发泡共混材料,并且使用发泡硫化仪等探索了四种合成橡胶的发泡硫化曲线,对比了它们的发泡倍率和密度,结果表明：A聚合体系ASTM混炼胶的焦烧时间和正硫化时间比B聚合体系快,最大扭矩值比B聚合体系高;A聚合体系的拉伸模量比B聚合体系高,B聚合体系的断裂伸长率比A聚合体系高;A聚合体系的发泡倍率比B聚合体系高,A体系发泡材料密度比B体系低。     

硫化工艺对天然橡胶发泡材料静刚度和动静刚度比的影响

研究硫化温度、时间和压力对天然橡胶（NR）发泡材料静刚度（Ks）和动静刚度比（Kd/Ks）的影响。结果表明：在一段硫化中,NR发泡材料的Ks随着硫化温度的升高、时间的延长和压力的增大而增大,Kd/Ks随着温度的升高而增大,随着时间的延长而减小,几乎不随压力变化。在二段硫化中,NR发泡材料的Ks和Kd/Ks随着硫化温度的升高和时间的延长而减小,随着压力的增大而先增大后减小。当一段硫化条件为115 ℃/10 MPa×15 min、二段硫化条件为150 ℃/10 MPa×10 min时,NR发泡材料能满足减震垫板成型的指标要求。     

硫化工艺对天然橡胶发泡材料静刚度和动静刚度比的影响

研究硫化温度、时间和压力对天然橡胶(NR)发泡材料静刚度(Ks)和动静刚度比(Kd/Ks)的影响。结果表明:在一段硫化中,NR发泡材料的Ks随着硫化温度的升高、时间的延长和压力的增大而增大,Kd/Ks随着温度的升高而增大,随着时间的延长而减小,几乎不随压力变化。在二段硫化中,NR发泡材料的Ks和Kd/Ks随着硫化温度的升高和时间的延长而减小,随着压力的增大而先增大后减小。当一段硫化条件为115℃/10MPa×15min、二段硫化条件为150℃/10MPa×10min时,NR发泡材料能满足减震垫板成型的指标要求。     

硫化工艺对橡胶微孔垫板尺寸稳定性的影响

分析了橡胶微孔垫板的硫化3要素。结果表明,随着硫化温度的升高和硫化时间的延长,产品厚度先增大后减小,硫化压力对产品尺寸无明显影响。在130℃±1℃×8min×19 MPa条件下,硫化速率和发泡速率具有较好匹配性,产品厚度和性能均满足技术要求。     

Foaming parameter identification of polyurethane using FOAMAT® device

A key problem in the modeling of polyurethane (PU) foaming is the determination of relevant physical parameters for the viscosity, the gas expansion, and the curing rate. Indeed, it is difficult to measure the chemical kinetics parameters as well as the viscosity of industrial PU formulations (polyol–isocyanate–water mixture) because the time scales of gas production and PU crosslinking are very short and hardly compatible with the installation of the sample in characterization devices such as differential scanning calorimetry and parallel plates rheometer. A FOAMAT® system has been developed to get these experimental data but the relationship between measurements and the rheo-chemical parameters has not been clearly established. In this paper, an analytical model of the foaming process is developed in the cylindrical FOAMAT geometry, which allows identifying the parameters of the curing and gas production kinetics equations, as well as the viscosity. This analytical model is based on a set of simplifying hypotheses which validity is checked using the finite element computation software REM3D dedicated to foaming modeling and applicable for injection-molding processing.     

150 mm厚金属面硬质聚氨酯泡沫夹芯板生产技术

提出了用20 m长的定型机生产150 mm厚金属面硬质聚氨酯泡沫夹芯板出现的问题,分析了硬质聚氨酯泡沫夹芯板产生裂纹和变形的原因,并对传统的原料体系配方和生产工艺进行改进。通过调整原料中的水分含量、发泡体系反应速度、增加固化时间等工艺参数,在20 m长的定型机上生产出了合格的150 mm厚金属面硬质聚氨酯泡沫夹芯板产品。     

Polymerization induced viscoelastic phase separation of porous phenolic resin from solution

The porous structure evolution of thermosetting phenolic resin controlled by polymerization induced viscoelastic phase separation from solution was investigated in this work. The ultimate morphology and the evolution of a porous texture for the resol resin/solvent system were characterized by digital camera and optical microscopy. In-situ Fourier transform infrared spectroscopy and a rheological method were used to trace the curing reaction of the resol resin/solvent system. The impacts of solvent content and curing temperature on the foaming behavior were quantitatively and systematically investigated. Based on the relationship between the morphology evolution and curing dynamics, the foaming mechanism of the polymerization induced viscoelastic phase separation was elucidated. The present work provides new insight into the foaming mechanism of thermosetting materials and may be helpful for morphological control in the preparation of lightweight porous phenolic material. © 2016 Society of Chemical Industry     

非异氰酸酯法大豆油基泡沫材料的研究

以丙烯酸酯化环氧化大豆油及改性偶氮二甲酰胺为起始原料,在自由基引发下模塑固化发泡制备出新型大豆油油基泡沫材料,该方法不依赖异氰酸酯原料。研究了发泡体系的热分解特性、泡沫材料的固化度、压缩性能及泡孔形态。     

杨木粉制备泡沫的工艺研究

以杨木粉为原料,通过液化制成液化树脂,再对液化树脂采用中低温发泡法制备发泡材料,系统地考虑了液化树脂黏度和固体质量分数、发泡温度以及表面活性剂、固化剂、发泡剂用量和种类等因素对制备工艺的影响。结果表明：适宜的发泡条件为杨木粉液化树脂黏度为6 000 mPa·s、固体质量分数为75%,发泡温度75 ℃,以吐温-80与OP-10（质量比1∶1）复配作为表面活性剂,以正戊烷为发泡剂,1,4-丁内酯为固化剂,用量都在8%~12%,该条件下发泡过程稳定,制得的泡沫泡孔细腻,均匀,闭孔率高,表观质量好,泡沫的表观密度小（0.12~0.16 g/cm³）并且发泡倍率高（5~8倍）。     

硫化发泡体系对硅橡胶泡沫材料应力松弛性能的影响

考察了过氧化二异丙苯/N,N-二亚硝基五次甲基四胺(DCP/H)、2,5-二甲基-2,5-二叔丁基过氧化己烷/偶氮二甲酰胺(双二五/AC)和过氧化苯甲酰(BPO)/AK 3种硫化发泡体系及助交联剂TAIC对硅橡胶泡沫材料力学性能和压缩应力松弛性能以及泡孔结构的影响。结果表明,DCP/H硫化发泡体系的力学性能和应力松弛性能优于双二五/AC和BPO/AK,添加适量助交联剂TAIC有助于进一步降低硅橡胶泡沫材料的应力松弛性能。扫描电镜(SEM)观察发现,DCP/H硫化发泡体系对应的硅橡胶发泡材料泡孔较小且分布均匀,当加入适量的助交联剂TAIC后,硅橡胶泡沫材料的泡孔更加细小均匀。     

室温发泡酚醛树脂的正交试验研究

以磷酸、硫酸、对甲苯磺酸为固化剂,制备了室温发泡酚醛树脂矿用填充材料,通过正交试验设计研究了固化剂各组分的用量对树脂的发泡时间、发泡倍数、最高发泡温度等性能指标的影响。结果表明,当酚醛树脂、固化剂、表面活性剂、发泡剂质量比为100：49：4：18时制备的可发泡酚醛树脂综合性能指标最好。     

Microcellular foaming of silicone rubber with supercritical carbon dioxide

In spite of great concern on the industrial application of microcellular silicone rubber foams, such as in electric and medical devices, only a few works can be found about the foaming of silicone rubber. In this study, microcellular silicone rubber foams with a cell size of 12 μm were successfully prepared with curing by heat and foaming by supercritical CO₂ as a green blowing agent. The microcellular silicone rubber foams exhibited a well-defined cell structure and a uniform cell size distribution. The crosslinking and foaming of silicone rubber was carried out separately. After foaming, the silicone rubber foam was cross-linked again to stabilize the foam structure and further improve its mechanical properties. Foaming process of cross-linked silicone rubber should be designed carefully based on the viscoelastic properties because of its elastic volume recovery in the atmosphere. The basic crosslinking condition for small cell size and high cell density was obtained after investigating the rheological behavior during crosslinking.     

改性氰酸酯发泡胶膜的制备与性能

采用环氧树脂和热塑性树脂改性氰酸酯树脂的方法,研制了改性氰酸酯发泡胶膜。用示差扫描量热法研究了发泡胶膜的固化特性。研制的发泡胶膜具有良好自粘性,室温贮存期为20d。180℃固化后,膨胀比在1．5—3．5之间,200℃管剪强度大于4MPa。试验结果表明,该发泡胶膜能满足高性能雷达天线罩结构粘接要求。     

聚合MDI中二环化合物含量对发泡性能的影响

制备了不同2，4’-MDI含量、不同二环化合物含量的聚合MDI样品，分别与以CFC-1l和环戊烷为发泡剂的组合聚醚进行了发泡实验，考察了其流动性和脱模性能与组成的关系。实验结果表明，当聚合MDI与2种组合聚醚进行发泡时，2，4’-MDI含量对聚合MDI的发泡流动性影响较小，而对后熟化性能的影响明显，随2，4’-MDI含量的增加，脱模变形呈直线上升的趋势。与此对应，无论是CFC-1l型组合聚醚还是环戊烷型组合聚醚，二环化合物含量对聚合MDI的发泡流动性能和后熟化性能影响很大，是影响聚合MDI应用性能的关键因素。二环化合物含量的增加，可以显著地提高泡沫的发泡高度指数、降低密度分布系数，改善聚合MDI的发泡流动性能，但泡沫的脱模变形量增大，后熟化性能明显变差。