悬乳剂及其稳定性

悬乳刑是一种包含悬浮剂和水孔剂的农药新剂型,有效成分的复杂性使得其制剂稳定性交得更加困难。助剂的选择是至关重要的。本文概括了助剂所起的作用及悬乳剂的稳定性研究进展。     

烟嘧磺隆油悬剂的开发与应用

介绍了烟嘧磺隆的发展及油悬剂的制备,重点论述了4％～6％烟嘧磺隆油悬剂配方的分散介质、助剂的筛选,成功开发研制出了合格配方并在玉米田安全应用。     

五氯酚油悬剂的研制

本文主要叙述了五氯酚油悬剂的研制过程及产品标准。     

悬顶装配式炼焦炉

悬顶装配式炼焦炉张家芳，寇振宇忻州地区科委（山西０３４００）当前推广的各种改良型炼焦炉，如ＬＬ型焦炉、７５型焦炉、ＸＹ型焦炉、介休炉等都是窑洞式结构，炉顶是由耐火砖砌筑的固定拱顶。多年的生产实践证明，在炼焦过程中，由于炉内温度高，又是内熄焦生产工艺，...     

头孢呋辛酯掩味干混悬剂的制备

通过固体分散体技术采用熔融硬脂酸包裹进行掩味,制备出口感较好的干混悬剂,并符合中国药典要求。采用硬脂酸为掩味材料,加热熔融后混入头孢呋辛酯制备成固体分散体,再进行干混悬剂的制备,并对其处方的最佳比例及其它组分的比例进行了实验筛选。结果表明,采用将2∶1的头孢呋辛酯原料加入75℃加热熔融的硬脂酸中,搅拌均匀粉碎后加入1.5%黄原胶,可以很好地掩盖头孢呋辛酯的苦味,同时能符合中国药典对干混悬剂的要求。     

硫磺及其混合流悬剂(胶悬剂)的开发研究

本文报导硫磺及其混合流悬剂的开发研究,制剂明显地提高了硫磺防治病虫害的效果并扩大了应用范围,其中多硫(灭病威)和硫环唑等混合流悬剂的效果尤为突出,试验证明其经济效益、社会效益、与生态效益都比较显著。我国硫资源比较丰富,它的开发利用具有重要的现实意义。     

杀虫剂巴沙水悬剂研制成功

广州市化工研究所于1986年研制成功25％巴沙水悬剂并通过了技术鉴定。25％巴沙水悬剂是将液状农药采用水包油型乳状液加工技术制成的新剂型。该制剂的主要特点:以水为介质,不用有机溶剂,悬浮率     

MSR—40型悬链埋刮板输送机在输灰系统中的应用

ＭＳＲ－４０型悬链埋刮板输送机在输灰系统中的应用高成恩（扬州电力劳动服务公司）１概况扬州电厂扩建的２×２００ＭＷ燃煤机组于１９８９年建成投产。设计采用灰渣混除水力除灰和电气除尘器一电场干灰采用双仓泵正压气力输送的除灰系统，并留有二、三电场出干灰的条件...     

钙镁磷肥高炉悬料原因的探讨

本文对高炉熔制钙镁磷肥过程中出现的悬料故障进行深入探讨,阐明形成悬料的全过程,既有力学机理又有物化性能的影响,并提出处理悬料的措施。     

水悬乳剂

水悬乳剂导言水悬乳剂（代号ＳＥ）是由两种或多种水不溶的有效成分分散在水溶液中的混合物，其中一种（或多种）有效成分处于悬浮状态，另一种（或多种）有效成分处于乳液状态。该制剂用水稀释后喷洒使用。几种有效成分共用，往往具有广谱防治效果。该剂型使几种有效成分...     

Drop mixing in suspension polymerisation

In suspension polymerisation, monomer is suspended as liquid droplets in a continuous water phase by means of strong agitation and the presence of a suspending agent. As the suspension polymerisation proceeds, the viscosity of a monomer-polymer droplet increases with conversion. Hence, the physical behaviour of the droplet changes during the process. When new dispersible material is added to the existing suspension drops, the new material and existing drops can remain segregated for significant amounts of time. The aim of this project was to study the behaviour of drop mixing when new material is added to the existing suspension polymerisation. This study concentrated on the effect of the dispersed phase viscosity on drop mixing. The results show that viscosity affects drop size and that may then affect the rate of coalescence between drops. A critical drop size exists which determines the coalescence efficiency effect. Above the critical drop size, mixing rate increases as the drop viscosity decreases. While below the critical drop size, drop size of the dispersion determines the coalescence rate; as the drop size increases, coalescence rate also increases. The investigation of the effect of suspending agent shows that Tween 20 is more efficient in stabilising and protecting the drops, based on a weight basis, than PVA as the coalescence rate is lower with Tween 20.     

ON THE EFFECTIVE CONDUCTIVITY OF A DILUTE SUSPENSION OF SPHERICAL DROPS IN THE LIMIT OF LOW PARTICLE PECLET NUMBER

In this paper we consider the effective conductivity of a dilute suspension of neutrally bouyant spherical drops which is undergoing a simple shear flow. The thermal conductivity, viscosity and specific heat capacity of the drops are assumed to be different from those of the suspending fluid, though it is assumed that the local Peclet and Reynolds numbers are small both inside and outside the drop. The analysis consists of three parts: a derivation of the relationship between bulk heat flux on the one hand and the thermal and momentum fields at the microscale of the suspended particles on the other; a calculation of the local temperature field near a single neutrally buoyant spherical drop in shear flow with an imposed transverse temperature gradient at large distances; and a synthesis of the general relationship for bulk heat flux and the calculated local temperature field to determine an effective conductivity for a dilute suspension of spherical drops.     

The influence of poly(vinyl alcohol) suspending agents on suspension poly(vinyl chloride) morphology

The requirements for PVC suspension resin have changed considerably in the last few years, so much so that few companies have products on their ranges that are more than 4 or 5 years old. The suspending agent has a crucial influence on the morphology of the resin, so the changes in resin characteristics have largely been achieved by changes in the suspending agent systems. After a brief review of the mechanism of PVC suspension polymerisation, the properties of polymers made using PVOH suspending agents are related to changes in the latter. The effect of variations in PVAc degree of hydrolysis and viscosity are related to changes in surface tension. Methods of achieving higher porosity by using low hydrolysis co-suspending agents are described. It is shown that higher bulk densities can be achieved by delayed addition of the PVOH. Levels of conjugated unsaturation and copolymer distributions are also shown to have important influences.     

The use of polyelectrolyte stabilisers for suspension polymerisation: the effect of pH on particle size distribution

Ammonium polymethacrylate (APMA) and sodium polymethacrylate (PMA‐Na) were used as suspending agents for the suspension polymerisation of methyl methacrylate (MMA). The effect of pH on particle sizes and the stabilisation mechanism were examined. Increasing the pH caused a decrease in the particle sizes, and the formation of fine particles with diameters smaller than 10 µm. The amount of suspending agent required to stabilise a monomer dispersion and to prevent coalescence during suspension polymerisation decreases with increasing pH. The prevailing stabilisation mechanism that governs the dispersion stability is probably the electrosteric mechanism. Copyright © 2006 Society of Chemical Industry     

Nonaqueous polymerization of vinyl chloride: An environmentally friendly process

Poly(vinyl chloride) (PVC) is produced via a nonaqueous polymerization process in which hexane is used as a diluent. This nonaqueous process can lead to significant energy savings, significant reductions in carbon dioxide emissions, and the elimination of wastewater. Various suspending agents have been used to evaluate their effects on the shape and morphology of PVC grains. The nonaqueous process leads to the formation of PVC grains with higher porosity than that of typical suspension PVC. The bulk density is slightly lower than that of suspension PVC, but the thermal stability seems to be similar. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effects of hydrophobic interaction on rheological behavior and microstructure of carboxylated core‐shell latex suspension

We have investigated the effects of hydrophobic interactions on the rheological behavior and microstructure of suspension of carboxylated core‐shell latex particles with changing hydrophobicity of shell polymer and suspending medium. The carboxylated core‐shell latex particles formed lattice‐like microstructures in aqueous suspension with dissociation of carboxyl groups. With increasing hydrophobicity of the shell polymer, the interparticle distance ξ in the microstructure decreased. However, ξ increased with increasing hydrophobicity of the suspending medium. The effect of hydrophobic interaction on ξ was explained by the steric stabilization theory for particles with grafted polymer on the surface. As the carboxylated core‐shell latex particles overlapped each other in the microstructure, an attractive force was generated between the particles in aqueous suspension. With increasing hydrophobicity of the shell, the attractive force increased, but with increasing hydrophobicity of the suspending medium, the attractive force decreased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4153–4158, 2006     

重组人酸性成纤维细胞生长因子滴眼液的制备及其稳定性

目的制备重组人酸性成纤维细胞生长因子(rhaFGF)滴眼液,并进行稳定性检测。方法在rhaFGF中添加复方保护剂,并以透明质酸钠作为保湿剂,制备rhaFGF滴眼液,对其进行鉴定和体外药效学检测,并进行稳定性试验。结果制备的3批滴眼液各项质量指标均合格,可促进碱烧伤家兔角膜细胞和鸡胚绒毛膜血管增殖。在4℃保存12个月,-20℃保存18个月,(25±2)℃保存6个月,滴眼液各项质量指标与0月基本一致。结论制备的rhaFGF滴眼液稳定性良好,可促进损伤角膜细胞修复。     

Suspension polymerisation of methyl methacrylate using sodium polymethacrylate as a suspending agent

Aqueous solutions of sodium polymethacrylate (PMA-Na) are used as suspending agents for the suspension polymerisation of methyl methacrylate. These aqueous polyelectrolyte solutions are viscous and they show a non-Newtonian shear thinning behaviour. The Sauter mean drop diameter decreases with increasing continuous-phase viscosity, but increases with increasing stirring speed. The maximum drop sizes follow the same trends. The Sauter mean diameter also decreases, initially, for increasing hold-up, reaches a minimum, and then increases with increasing hold-up. Taylor's theory of viscous break-up seems to be suitable to describe the breakage of the droplets.     

Crosslinked phenol-formaldehyde sulphonates as cation exchangers

The suspension polycondensation of phenol sulphonic acid and its homologues with formaldehyde, to produce a satisfactory cation exchanger in the bead form in the presence of sulphuric acid catalyst, was investigated. The various reaction conditions for bead formation, using an organic liquid suspending medium in the presence of a suspension stabiliser, such as the nature and quantity of the suspension stabilisers, the quantity of water added, the nature and quantity of the organic suspending medium and the rate of mixing, were studied. o-Dichlorobenzene was the best organic suspending liquid and a chemically peptised colloidal kaolin suspension was a good suspension stabiliser in the presence of a wetting agent. The optimum reaction conditions were given. The best exchangers were obtained in good yields using a molar ratio of phenol: HCHO:H₂SO₄ of 1·0:2·5:1·5 or a mixture of equimolecular amounts of phenol and resorcinol in a molar ratio of mixed phenols: HCHO: H₂SO₄ of 1·0:1·0:1·5. The efficiency of all the products obtained was measured by determination of their total exchange capacity.