木纹结皮发泡PVC异型材的挤出

用普通单螺杆挤出机和自制结皮发泡模具,应用不同树脂进行配方工艺试验,结果表明：利用不同材料的流动性差异,并结合模具进行设计,可以挤出木纹效果良好的ＰＶＣ结皮发泡异型材。     

成型工艺对超临界CO_2发泡PP结构与性能的影响

采用自制超临界流体反应釜装置,以超临界CO_2作为物理发泡剂,进行聚丙烯(PP)材料的发泡试验研究。探讨了超临界CO_2发泡PP时的发泡温度、发泡压力和泄压速率对PP发泡材料的宏观性能及泡孔结构的影响。结果表明,发泡温度为135℃时,发泡材料的表观密度最小,为0.096 g/cm3;发泡压力为12 MPa时,发泡材料的表观密度最小,为0.075 g/cm~3,当发泡压力继续上升时,PP发泡材料的表观密度有所上升但泡孔直径开始下降;泄压速率为2 MPa/s时,发泡材料的表观密度最小,为0.196 g/cm~3,泡孔的平均直径最大。     

结皮发泡PVC塑料板材生产技术和质量影响分析

近年来,随着工业生产的不断发展,结皮发泡工艺有着更为广泛的应用空间,尤其是结皮发泡PVC塑料板材的生产与应用。当前,结皮发泡PVC塑料板材的生产工艺与其他的塑料挤出制品相比,具有更好的塑化成型能力,同时也拥有数量和大小分布都更为均匀的特点。影响结皮发泡PVC塑料板材生产质量的因素有很多,本文则简要介绍一下结皮发泡PVC塑料板材的生产技术,并且对其质量影响因素进行详细的分析。     

蓖麻油酸镧对聚氨酯自结皮泡沫性能的影响

采用硝酸镧、蓖麻油酸为原料, 利用复分解法制备了蓖麻油酸镧。以蓖麻油酸镧作为催化剂, 作用于全水发泡聚氨酯自结皮泡沫材料, 考察了蓖麻油酸镧对全水发泡聚氨酯自结皮泡沫材料性能的影响。采用傅里叶红外光谱仪、紫外可见分光光度计、生物显微镜、电子万能试验机等进行表征, 结果表明蓖麻油酸镧对全水发泡聚氨酯自结皮泡沫材料的影响作用明显, 稀土元素的加入使泡沫材料的体系结构发生变化。加入蓖麻油酸镧后可明显缩短泡沫的脱模时间, 改善了泡沫强度和表皮硬度, 对形成稳定良好的泡孔结构有一定的促进作用, 添加0.3份和0.6份的蓖麻油酸镧制取的泡沫泡孔形态较好。     

高发泡聚丙烯研发获重要进展

中科院宁波材料所研发的超临界流体发泡通用大品种聚丙烯项目日前取得重要进展，实现了高发泡倍率（密度小于0．04g／cm3）发泡聚丙烯的长时问稳定量产，且生产重复性好。他们在此基础上开发的低发泡倍率的聚丙烯微发泡仿藤条产品及窄幅片材产品引起了厂家的兴趣。     

热塑性聚氨酯/马来酸酐接枝聚丙烯微孔发泡材料的制备与力学性能

采用超临界二氧化碳发泡一步泄压法制备热塑性聚氨酯/马来酸酐接枝聚丙烯(TPU/PP-g-MAH)微孔发泡材料。通过对PP-g-MAH与TPU分子间相互作用机理的深入研究,发现PP-g-MAH与TPU分子链间存在的强烈氢键作用有利于提高TPU发泡材料的孔隙率。添加质量分数3%的PP-g-MAH即可制备低密度(0. 1 g/cm3)、大发泡倍率(ER10)的TPU微孔发泡材料。经10次压缩-回复循环测试后,所有样品的最大压缩应力的保持率均大于80%,表现出良好的弹性和形状稳定性。     

PUR发动机装饰罩表面处理有效提升整车NVH性能

PUR发泡发动机装饰罩已经成为汽车行业的一个成熟产品,和普通发动机装饰罩相比,有效提升了整车NVH性能。为了进一步提升整车NVH性能,研究了内表面针刺和去除内结皮,2种工艺的PUR发泡发动机装饰罩对整车NVH性能的影响。首先从有无表面结皮和材料厚度,2方面对原材料的吸声系数进行测试,然后从零件外表面皮纹腐蚀和内表面针刺处理、去除内表面结皮对PUR发泡发动机装饰罩完成了零部件NVH性能测试。在此基础上,完成了整车NVH性能测试。研究结果表明,内表面针刺处理和去除内表面结皮均能有效提升整车NVH性能,其中,针刺处理的效果更显著。     

含硅酸钙(CaSiO_3)天然橡胶胶乳制备的半硬质发泡材料

<正>在天然橡胶胶乳的硫磺硫化体系中,分别加入0份、2份、5份、10份、20份和30份CaSiO_3,制备半硬质发泡材料。CaSiO_3能够提高发泡材料的力学性能、热学性能和物理性能。CaSiO_3的最佳填充量是30份,此发泡材料的体积密度为1.2230 g/cm~3,复合发泡密度为0.3611 g/cm~3,抗压强度为588.10 kPa,在     

SBS模压高发泡鞋用材料的研究

采用模压法制备了SBS发泡材料,并测试了发泡材料的密度。重点研究了配方组成如发泡剂AC用量、交联剂的种类和用量、发泡促进剂ZnO/AC配比对发泡倍率的影响。考察了制备工艺即模压温度和模压时间对SBS发泡倍率的影响。结果表明:在合适的工艺和配方条件下,可制得密度为0.26g/(cm)～3的SBS发泡材料。     

浅析UPVC结皮低发泡钢塑共挤型材堵料问题

硬质聚氯乙烯结皮低发泡钢塑共挤型材(简称JFG型材)自1997年问世以来，先后在北京、河北、山东、黑龙江、新疆、云南等地投产。它采用钢塑复合技术及结皮低发泡生产工艺，将U—PVC发泡材料巧妙地复合在异型钢衬上，形成表层为U—PVC结皮层，中间为U—PVC发泡层，里面为钢衬的多层结构，是一种“钢塑     

Experimental investigation on mechanical properties of extruded foamed PVC‐wood composites reinforced with continuous glass fibers

In this study, mechanical performances of extruded foamed and unfoamed PVC‐wood composites, reinforced with continuous glass fibers, were investigated. A specially designed die was used to incorporate the continuous glass rovings into the extruded rectangular shaped profiles. The experimental variables were the number of continuous glass rovings (0–2‐4) and the presence or absence of the chemical foaming agent. Three point bending tests as well as density measurements were conducted to evaluate the mechanical properties and density reduction upon foaming. The results showed that the flexural strength of the reinforced profiles was significantly increased, as 58% increase in flexural strength was noticed for wood plastic composites (WPCs) reinforced with four glass rovings. The highest density reduction (14%) was observed upon foaming for profiles reinforced with four glass rovings, while resulting in strength deterioration. Moreover, results revealed the remarkable effect of reinforcement on preserving mechanical performance of the foamed samples, as 88% increase in flexural strength of the foamed samples reinforced with four glass rovings was observed compared with the unreinforced foamed ones. For the foamed WPCs reinforced with even two glass rovings, the higher specific strength values were also noticed compared to the unreinforced and unfoamed samples. POLYM. COMPOS., 37:1674–1680, 2016. © 2014 Society of Plastics Engineers     

软质PVC鞋底发泡材料的研制

以软质聚氯乙烯（PVC）为主体材料，加入发泡剂偶氮二碳酰胺（AC）、交联剂过氧化二异丙苯（DCP）、柠朦酸、丁腈橡胶（NBR）、泡孔调节剂等，采用一步法模压成型软质PVC鞋底发泡材料。研究AC，DCP、柠朦酸、NBR、泡孔调节剂用量对软质PVC发泡材料密度和力学性能的影响。结果表明，在AC4．0份、DCP0．2份、柠朦酸0．2份、NBR40．0份、泡孔调节剂11.0份时，发泡材料性能优异，其密度和力学性能满足软质PVC鞋底发泡材料的要求。     

软质聚氨酯泡沫塑料的研制

研究了以聚酯多元醇和异氰酸酯为主原料，采用水基发泡新工艺制取软质聚氨酯泡沫的配方。讨论了ＮＣＯ指数、发泡剂用量对泡沫性能的影响。为开发无氟里昂发泡技术提供了实验参数。     

镍铁渣砂对泡沫混凝土孔结构及收缩开裂性能的影响

本文采用镍铁渣机制砂(简称镍铁渣砂)制备泡沫混凝土,研究镍铁渣砂对泡沫混凝土抗压强度、变形及收缩开裂的影响,并采用SEM、X-CT研究泡沫混凝土微观结构。结果表明,镍铁渣砂掺量为5%(质量分数,下同)时泡沫混凝土的抗压强度最高,而镍铁渣砂掺量超过10%时会引入界面缺陷,降低混凝土的强度。镍铁渣砂能够约束基体的变形,减少水泥用量,降低泡沫混凝土的收缩,提高其抗裂性能。当镍铁渣砂掺量由0%增加到20%时,泡沫混凝土的抗裂等级由V级提高到II级。镍铁渣砂具有作为泡沫混凝土生产原料的潜力。     

泡沫陶瓷的研制

泡沫陶瓷是一种新型的功能陶瓷材料。它具有独特的结构和性能，在工业中有着广泛的应用前景。泡沫陶瓷具有密度小、透气性高、耐高温、抗化学腐蚀等特性。本研究对用颗粒强化的氧化铝骨架合成泡沫陶瓷进行了分析。这种材料比其它多孔陶瓷材料具有更好的热化学性质。这种材料可以用有机海绵浸浆获得，然后烧去海绵，留下多孔陶瓷网。这种方法的优点是它包含了过程参数和陶瓷结构，同时合成物的烧结情况及其它条件的影响在文中也有阐述。     

泡孔结构对泡沫发射药燃烧性能的影响

通过配方调节与工艺控制得到3种不同结构的泡沫发射药,讨论了泡孔结构形成的影响因素;采用密闭爆发器实验和恒压燃速测试实验研究了不同结构泡沫发射药的燃烧性能。结果表明,控制气体生成速率、添加RDX颗粒、调节NC含氮量和发泡时间能够有效控制泡沫发射药的泡孔结构;皮芯结构泡沫发射药具有渐增燃烧特性,发泡区的动态活度可达不发泡皮层的2.4倍以上;独立泡孔结构的泡沫发射药在100MPa下燃速可达未发泡样品的30倍;非独立孔隙结构的泡沫发射药不同方向上的燃速差异显著,密度为1.37g/cm~3的样品100MPa下轴向燃速最高可达3.860m/s。     

The effect of porosity on the strength of foamed concrete

A study has been undertaken to investigate the effects of replacing large volumes of cement on the properties of foamed concrete (up to 75% by weight) with both classified and unclassified fly ash. This is the third paper in a series; it investigates the relationship between porosity and compressive strength and presents mathematical models that have been developed to describe this relationship. The compressive strength of the foamed concrete was shown to be a function of porosity and age, and a multiplicative model (such as the equation derived by Balshin) was found to best fit the results at all ages up to 1 year. In addition, it was concluded that the equation derived by Hoff could effectively be used to predict the compressive strength of foamed concrete mixtures containing high percentages of ash.     

吸放热平衡发泡剂在PVC-U发泡异型材中的应用

介绍了PVC—U发泡异型材工艺特点和要求,分析了吸放热平衡发泡剂在PVC—U发泡异型材中的应用及特性。     

Rheological characteristics of foamed gel for mine fire control

Foamed gel as a new type of fire extinguishing material is used to prevent the spontaneous combustion of coal. In order to make a comprehensive study on rheological characteristics of foamed gel for mine fire control, by using type NDJ‐5s digital viscometer, the factors such as mass concentration of the mixture mixed by thickener and crosslinker, foaming multiple, added salts (NaCl, CaCl₂, AlCl₃), pH value and temperature having influences on the rheological properties of foamed gel have been investigated in this paper. It can be found that foamed gel shows the characteristic of non‐Newtonian fluids and has shear‐thinning properties. With increasing of mass concentration of the mixture, the thixotropy response becomes more significant. When the foaming multiple reaches 20, the apparent viscosity gets the maximum value. The obvious viscosity characteristic of ‘polyelectrolyte solution’ is observed in aqueous salt solutions when added salts are put into the solution. Under different conditions of pH values, foamed gel has higher sensitivity to acid than alkaline. Zero shear viscosity, depending on temperature, decreases with the temperature increasing. Meanwhile, the fire performances of foamed gel are studied experimentally and theoretically. Copyright © 2014 John Wiley & Sons, Ltd.     

低温下泡沫混凝土的动态力学性能

为了研究低温下泡沫混凝土的动态力学性能,采用φ100 mm的铝制分离式霍普金森压杆(SHPB)装置对不同温度下泡沫混凝土试件进行冲击压缩试验,得到了不同温度、应变率下的泡沫混凝土的应力应变曲线、能量参数、破碎形态等。结果表明:当应变率在62.59 s^-1以下时,泡沫混凝土应力应变曲线分为线弹性阶段、屈服阶段、破坏阶段;当应变率超过62.59 s^-1时,其应力应变曲线分为线弹性阶段、屈服阶段、局部失稳、应力平台、破坏阶段;常温、0 ℃、-10 ℃、-20 ℃和-30 ℃下,泡沫混凝土的动态抗压强度以及吸收能在对应的应变率分界点前表现出显著的应变率效应,但超出该分界点后,应变率效应便不再明显;泡沫混凝土的动态峰值抗压强度与吸收能随温度的降低而提高,但峰值应变随温度降低而降低;泡沫混凝土冲击破碎后的块度随着温度的降低逐渐变大。在低温环境下泡沫混凝土的抗动载设计中,对于泡沫混凝土的峰值抗压强度、吸收能,应优先考虑温度效应的影响,而对于其峰值应变,应优先考虑应变率效应。