聚脲交联改性丙烯酸酯弹性乳液的制备与性能研究

为了在性能上对聚脲交联改性后的丙烯酸酯乳液(PUA)和纯丙乳液(以)进行比较,文章以丙酮为溶剂,通过端氨基聚醚和甲苯二异氰酸酯的缩合反应合成了端异氰酸酯基聚脲预聚物,由于丙酮与胺基的可逆缩合反应,降低了胺基与异氰酸酯基反应的活性,从而可以更好地控制反应速度,降低副反应的发生几率.聚脲预聚体经丙烯酸羟乙基酯双键封端制备了含有2个双键的聚氨酯脲大单体,以其为外交联剂,通过与甲基丙烯酸甲酯、丙烯酸丁酯的乳液共聚反应制备了聚氨酯脲改性的纯丙弹性乳液,对乳液涂膜进行了FT-IR,DSC和TGA的表征.研究表明:PUA涂膜比PA涂膜具有更好的热稳定性、机械性能、耐低温性以及耐溶剂性.     

碱溶性聚(丙烯酸丁酯/丙烯酸)的合成及性能

合成了碱溶性聚(丙烯酸丁酯/丙烯酸)〔P(BA/AA)〕,探讨了丙烯酸用量及不同引发体系对其表面张力、离心稳定性和乳化性的影响,对其结构进行了表征。傅里叶红外光谱(FTIR)分析表明,P(BA/AA)中无C C存在,聚合完全;差示扫描量热(DSC)分析表明,共聚物的玻璃化转变温度(Tg)为21.3℃;透射电镜(TEM)测定了P(BA/AA)的平均粒径小于100 nm,粒径分布均匀。以该共聚物为表面活性剂与丙烯酸酯类进行乳液聚合制备了皮革涂饰剂,应用于皮革涂饰后,革样的物理机械性能较采用常规乳化剂制备的丙烯酸树脂涂饰革样抗水性提高了28.08%,透气性提高了18.5%,耐湿擦性提高了半级,耐折牢度无明显变化。     

用于膨胀型防火涂料的本体杂化乳液的合成及性能研究

成膜物对膨胀型防火涂料的性能有较大影响,有时对于涂料体系膨胀与否起决定性作用.本文将非水分散丙烯酸树脂在水性介质中与丙烯酸类单体进行杂化乳液聚合,合成了一种丙烯酸树脂/丙烯酸酯本体杂化乳液,用于膨胀型防火涂料.通过对乳液相对分子质量及分布和玻璃化转变温度的测试,表明该乳液具有明显的杂化乳液的特征.同时讨论了丙烯酸树脂的含量对乳液粒径、涂膜耐溶剂性能和光泽度的影响.     

高性能环氧树脂乳液的制备及性能研究

通过化学改性制备了一种性能优异的阳离子型环氧树脂乳液,对该乳液合成工艺进行了探讨,并研究了影响乳液及涂膜性能的因素。结果表明:采用环氧树脂E-51为原料制备的环氧树脂乳液稳定性好,分散相粒径为0.1～0.3μm,适用期为4 h,涂膜透明,硬度2H～3H,综合性能优良。     

一种微乳液清蜡剂的合成及性能研究

为了克服油基清蜡剂密度小、加注效率低和水基清蜡剂溶蜡速度慢等问题,通过对油相、表面活性剂、分散剂和加重剂的种类及添加量的分析,确定出微乳液清蜡剂最佳配方,其中主要包括混合有机溶剂%=55%、复配型表面活性%=17%,正己醇%=10%,氯化钠%=2%,甲酸盐加重剂%=3.5%,剩余为水,该微乳液清蜡剂的清蜡速率可以达到0.053 4 g/min,该配方主要采用在含有混合型有机溶剂和复配型表面活性剂的基础上,同时添加环保型的加重剂,来增加微乳清蜡剂的溶蜡速率和加入效率,进一步提高效益,降低成本。     

表面交联高吸水性树脂的合成及吸液性能研究

采用水溶液聚合法合成了聚丙烯酸钠高吸水性树脂(SAP),通过改变丙烯酸中和度和进行吸水性树脂的表面交联反应处理,考察SAP产品在常压及加压下(2kPa)吸生理盐水(0.9%NaCl水溶液)性能。结果表明,当丙烯酸中和度为80%(质量分数)时,以二甘醇为表面交联剂制备的SAP在常压及2kPa压力下吸生理盐水能力别为56 g/g和29 g/g。     

Poly(MAA-AN-DM)两性聚合物复鞣剂的制备及性能

以甲基丙烯酸(MAA)、丙烯腈(AN)和甲基丙烯酸二甲基氨基乙酯(DM)为原料,过硫酸铵(APS)为引发剂,水为反应介质,经自由基共聚合制备了Poly(MAA-AN-DM)两性聚合物复鞣剂,并将其用于皮革的复鞣。用红外光谱、核磁共振氢谱、凝胶渗透色谱、胶体电荷滴定等对聚合产物的结构和性能进行了表征。用多功能材料实验机和色度计考察了聚合物组成对复鞣革性能的影响。较佳合成条件为:聚合温度80℃,单体量比n(MAA)∶n(AN)∶n(DM)=0.9∶0.3∶0.3,引发剂w(APS)=1.5%,w(单体)=30%,反应时间5.0 h。胶体电荷滴定测出共聚物的等电点为4.36,凝胶渗透色谱分析出共聚物的数均相对分子质量为84 688,分散系数为2.07。用w〔Poly(MAA-AN-DM)〕=2%的聚合物对猪蓝湿革进行复鞣,可使蓝湿革收缩温度提高5.5℃,抗张强度增加76.5%,增厚13.2%,革身饱满、无败色现象。     

高光泽度丙烯酸酯乳液的制备及性能

以自制固体碱溶性丙烯酸酯树脂(A-30)为大分子表面活性剂、甲基丙烯酸甲酯(MMA)为硬单体、丙烯酸丁酯(BA)为软单体、丙烯酸(AA)为功能单体和N-羟甲基丙烯酰胺(NMA)为交联单体,采用半连续乳液聚合法合成了性能优良的纸张上光油用水性丙烯酸酯乳液。研究结果表明:当m(MMA)∶m(BA)=40∶56~45∶51、w(NMA)=3%(相对于总单体质量而言)以及w(A-30)=30%~50%(相对于乳液质量而言)时,乳液及其胶膜的综合性能良好,其硬度、附着力、储存稳定性、光泽度、耐磨性、耐水性及耐溶剂性俱佳,并且胶膜经有机溶剂擦拭22次后仍不掉色。     

清洁保养“二合一”的地面护理新方案

在传统地面清洗剂配方里加入功能型的碱溶性改性丙烯酸树脂或蜡接枝聚合物,即可配制具有清洁保养"二合一"功能的地面清洁剂,解决了传统清洁剂残留物发粘的问题,同时赋予清洁剂更多的附加价值,使其具有清洁作用的同时也具有上光、滋养或者保护的功能。使得地面清洁护理更加省时省力,更加经济。     

碱溶性丙烯酸酯乳液啤酒贴标胶的合成及性能研究

以BA(丙烯酸丁酯)和EA(丙烯酸乙酯)为软单体、MMA(甲基丙烯酸甲酯)为硬单体、混合羧基单体MAA(甲基丙烯酸)和AA(丙烯酸)为功能单体、十二烷基硫酸钠(SDS)/辛基酚聚氧乙烯醚(OP-10)为阴/非离子型复合乳化剂、过硫酸钾(KPS)和亚硫酸氢钠(Na HSO3)为引发剂,采用种子乳液聚合法合成了碱溶性丙烯酸酯乳液。研究结果表明:当m(软单体)∶m(硬单体)=2∶1、m(AA)∶m(MAA)=0∶1且w(—COOH)=7%(相对于单体总质量而言)时,乳液的Tg(玻璃化转变温度)为25.5℃、碱脱时间为11 min、耐水性(吸水率26.91%)相对最好、单体转化率(95.87%)和固含量(47.12%)相对最大,说明该乳液在热碱性条件下易脱胶且耐水性较强,完全满足啤酒贴标胶的使用要求。     

A study of the heat treating cycle for internally sealed concrete containing montan-paraffin wax beads

Cylindrical concrete specimens, with 2 ft. ³/yd.³ (0.074 m³/m³) of fine aggregate replaced by montan-paraffin wax beads, were placed in a heating chamber designed to heat only their top surface. The heating cycle was varied to determine the optimum for the equipment used. After cooling, the specimens were cut longitudinally and subjected to an acid etching process to determine the depth of sealing. The maximum allowable surface temperature was found to be 425° F. (218° C.) if the deterioration of the wax due to heating was to be limited to a depth of $\text{1}\text{32}$ in. (0.8 mm.). The maximum depth of complete sealing was $\text{1?1}\text{16}$ in. (27 mm.). No significant reduction in the total duration of the heat treating process was found.     

A study of the alcohols of carnauba wax

Summary and Conclusions 1. Fractional crystallization alone is not an adequate method for isolating pure alcohols from carnauba wax. 2. More than 50 per cent of the alcohols of carnauba wax can be distilled at 0.5 mm. pressure without serious decomposition. 3. Fractional distillation of the free wax alcohols at 0.5 mm. is a useful method of separating these compounds, but recrystallization of the resulting fractions is necessary. 4. There are substances in the unsaponifiable portion of carnauba wax which are of an unknown nature but which are probably not n-aliphatic alcohols. 5. For the first time, three alcohols, octacosanol (C₂₈), triacontanol (C₃₀), and dotriacontanol (C₃₂) have been isolated from carnauba wax in states of purity of 95 per cent or better. 6. Dotriacontanol is even more abundant in the wax than is triacontanol. Submitted in partial fulfillment of the degree of Doctor of Philosophy, the Graduate School.     

The pressure effect on the wax formation in diesel fuel☆

The prevention of wax formation under high pressure on new diesel engine requires a good understanding of the behaviour of the paraffin molecules crystallization. In this work a diesel from a Petrogal refinery was investigated under pressure. In particular the melting curve was measured from atmospheric pressure to 100 MPa by an optical technique. The behaviour of the solid phase with the pressure was also investigated up to 50 MPa by filtration. The results obtained show an increase in the diesel cloud point of about 25 °C at the operating pressure of a common rail engine. It is clear from our results that the increase of the diesel cloud point must be taken into account in the development of new diesel engines where the diesel is injected under high pressure.All the results obtained were successfully predicted with a thermodynamic model able to describe multiphase equilibrium.     

影响沥青蜡含量准确分析的因素

简单介绍了石油沥青蜡含量的测定方法,对影响蜡含量准确分析的因素进行了剖析。结果表明：裂解蒸馏速度、馏出油取样量、乙醇纯度、温度、冷洗剂加入量、抽滤过程、砂芯漏斗的孔径是影响测定结果的显著因素。     

X-ray study of hydrogenated jojoba wax

Crystallographic analysis of hydrogenated jojoba wax ester shows the crystal structure to be monoclinic with orthorhombic perpendicular, 0⊥, chain packing. Cell dimensions are: a=4.99, b=7.44, c=55.2Å, β=90°. A larger secondary unit cell is observed and identified as permitting the hydrocarbon ester chains freedom of rotation. Hydrogenated jojoba was ester is crystallographically similar to polyethylene.     

Retardation effect of jojoba chain length on the chemical reactivity of the liquid wax

Jojoba wax and its derivatives are slow-reacting compounds. To elucidate the reasons for this phenomenon, we reacted jojoba mono- and bis-epoxide and trans-jojoba bis-epoxide (C₃₈–C₄₄ long-chain esters), as well as side chain esters of three steroid skeleton mono-epoxide derivatives with NaI under acidic conditions to yield the corresponding iodohydrins, which then formed the respective bis-keto (or mono-ketone) derivatives. The kinetics, activation energies, and thermodynamic parameters of activation of nucleophilic epoxide opening and pinacol rearrangement were determined for all these compounds. The reaction rates of the jojoba derivatives were similar to those of two of the epoxides derived from the steroid skeleton compounds, and in the third case the steroid derivative reacted somewhat faster than all the rest. This pattern of rate retardation could stem either from folding of the long jojoba chain, resulting in steric hindrance around the reaction centers, or from repeated unproductive collisions along the long hydrocarbon chain of the jojoba wax (statistical effect). Our results appear to suggest that the multiple unsuccessful collisions were the dominant factor, although steric hindrance cannot be ruled out.     

The effect of temperature and wax content on the appearance of turbidity in sunflowerseed oil

Turbidity in refined sunflowerseed oil, caused by the presence of waxes, is a frequent occurrence. As such, it is a special problem in a number of countries where clear packaging is used for this oil. The application of cold test for the determination of sunflowerseed oil clarity is not always satisfactory, as the negative cold test is not a guarantee that the waxes are completely removed and that the oil will remain clear for a longer period. In this study, the threshold value for wax content which would cause turbidity in refined sunflowerseed oil was determined. At the same time, the influence of cooling temperature and wax content on the visible turbidity appearance rate was investigated. The results show that the turbidity threshold for the cold test is 80 mg wax/kg oil, and that the rate of the visible turbidity appearance of the oil depends both on wax content and cooling temperature.     

稳定剂对高固含量石蜡乳液稳定性的影响

在石蜡乳液体系中,加入0.2%PVP、0.1%可溶性淀粉、0.2%膨润土或0.1%无水MgSO4均能改善石蜡乳液的稳定性,可使固含量为50%的石蜡乳液在3 000 r/m in的转速下离心30 m in不分层,常温下,乳液的表观粘度为370~630 mPa.s。     

氧化聚乙烯蜡乳液的组成研究

在常压下制备氧化聚乙烯蜡乳液,研究乳化剂的用量、水蜡质量比以及助乳化剂种类、含量等因素对氧化聚乙烯蜡乳液粒径的影响。研究助乳化剂碱性添加物和短链异构醇对氧化聚乙烯蜡乳液粒径的影响。结果表明,氧化聚乙烯蜡乳液的最佳组成为：m[乳化剂（平平加O＋Span-60）]∶m（氧化聚乙烯蜡）=25∶100,m（水）∶m（氧化聚乙烯蜡）=2∶1;乳化剂最佳组成：m（平平加O）∶m（Span-60）=4∶1;助乳化剂的比例：m（三乙醇胺）∶m（氧化聚乙烯蜡）=5∶100,m（异辛醇）∶m（氧化聚乙烯蜡）=3∶100,所得乳液平均粒径为0.341μm。     

聚乙烯蜡氧化及接枝改性研究

高密度聚乙烯生产过程中副产聚乙烯蜡,采用空气催化氧化法和马来酸酐接枝法均可在聚合物分子链上生成羧基或马来酸酐极性基团,可大大提高聚乙烯蜡的应用价值。采用空气催化氧化法,氧化温度为145~155℃,空气流速为5~6 m/s,复配催化剂(M1∶M2=1∶1)量0.4%~0.5%,连续氧化6 h,可获得微黄色酸值为24.0~27.0 mg KOH/g的氧化聚乙烯蜡;采用马来酸酐接枝法最佳条件:反应温度155℃、反应时间5 h、引发剂加入量2.0%、MAH加入量5%,可获得酸值为48.30 mg KOH/g的接枝聚乙烯蜡。挤出接枝法采用自动化连续生产方法,在挤出温度80~90℃,转速30 r/min,扭矩0~4 N.m,引发剂和MAH加入量分别为2.0%和15%条件下,可得到酸值为17.6 mg KOH/g的接枝产品。