共查询到19条相似文献,搜索用时 187 毫秒
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介绍了一种乳液聚合方法.通过种子乳液聚合,调整单体比例,引发剂和乳化剂的品种及数量,确定当丙烯酸丁酯和苯乙烯占单体总量的90%~94%,功能单体N-羟甲基丙烯酰胺和丙烯酸羟乙酯占单体总量的2.5%~4.5%,引发剂用量占单体重量的0.9%,阴、非离子乳化剂比例为1∶3,乳化剂总量为单体总量2%,丙烯酸用量为单体总量的3... 相似文献
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选用过硫酸钾(KPS)作为引发剂,阴-非复合表面活性剂L为乳化剂,丙烯酸丁酯(BA)、丙烯酸异辛酯(EHA)和甲基丙烯酸甲酯(MMA)为主单体,丙烯酸(AA)为功能单体,N-羟甲基丙烯酰胺作为交联单体,软硬单体以1.38∶1的配比乳化3h,得到聚丙烯酸酯类无皂乳液粘合剂。最终确定较佳合成工艺:引发剂用量0.4%,乳化剂用量0.8%,交联单体用量3.0%,功能单体用量1.2%。 相似文献
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采用硅烷偶联剂(KH-570)对纳米二氧化钛进行表面处理,然后以过硫酸钾为引发剂,与甲基丙烯酸甲酯、甲基丙烯酸丁酯等主要共聚单体通过乳液聚合方法,合成纳米二氧化钛/丙烯酸酯复合乳液。研究了聚合温度、引发剂用量、乳化剂用量、改性纳米二氧化钛用量等对丙烯酸酯单体转化率、乳液粒径及分布等的影响。通过傅里叶红外光谱仪表征了改性前后纳米二氧化钛性能,采用透射电镜、激光粒度仪对所制备的复合乳液进行了表征。结果表明:当反应温度为85℃,乳化剂用量为5%,引发剂用量为0.5%,改性纳米二氧化钛用量为2%时,反应单体转化率高达95%以上;且乳液粒径相对较小,分布较窄。 相似文献
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采用乳液聚合的方法,以丙烯酸丁酯(BA)和苯乙烯(St)为单体,十二烷基二苯醚二磺酸钠(DB-45)及壬基酚聚氧乙烯醚(NP-40)为乳化剂,过硫酸钾(KPS)为引发剂,通过加入功能性单体甲基丙烯酸六氟丁酯(HFBMA)和交联性单体N-羟甲基丙烯酰胺(NMA),合成一种阴离子表面施胶剂.利用IR、DSC、SEM、粒度分析、接触角分析、XPS等现代仪器分析技术对表面施胶剂的物理及化学特性进行表征.结果表明:m(BA):m(St)=1:1,复合乳化剂m(DB-45):m(NP-40)=4:1,总用量为单体质量的3%,引发剂用量为0.25%,交联性单体用量为1%. 相似文献
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采用反应单体预乳化的方式,引入自制阳离子单体及带有亲水性基团的双官能团交联剂,以氧化-还原体系的引发剂降低反应温度,合成高固体含量的阳离子丙烯酸树脂乳液。着重探讨了反应的工艺控制及阳离子单体、交联剂、引发剂用量对最终产物性能和乳液体系稳定性的影响。 相似文献
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The influence of medium composition on the release and volatility (vapour/liquid partitioning) of volatile lipid oxidation products was studied in order to explain the differences in composition of volatiles released from oxidised sunflower oil and its 40% oil-in-water emulsion in a model mouth system. Volatile compounds were analysed by gas chromatography combined with flame ionisation detection and mass spectrometry. Larger amounts of volatiles, formed during oxidation, were released from the emulsion than from the bulk oil. Differences in release influenced the results as well as the partitioning, but showed contrary effects. Added reference compounds were released in larger quantities from the oil than from the emulsion in the model mouth, and higher vapour/liquid partitioning values were obtained for the emulsion in comparison with the oil. In addition, water and saliva components influenced the release of reference compounds in the model mouth and the partitioning, giving different results for the oil and the emulsion. In conclusion, differences in the release of volatile compounds due to medium composition influenced the composition of the volatile lipid oxidation products of sunflower oil and its emulsion, as well as the lipid oxidation rate. 相似文献
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以聚乙烯醇(PVA)为高分子胶体稳定剂,甲基丙烯酸缩水甘油酯(GMA)为交联剂,丙烯酰胺(AM)、丙烯酸(AA)、丙烯腈(AN)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为共聚单体,通过无皂乳液共聚制备了交联型两性聚丙烯酸酯表面施胶剂。对阳离子基单体和交联性单体的用量、合成工艺条件等对纸张增强效果的影响进行了探讨。确定了较佳的合成条件:种子聚合法,w(PVA)=3%-4%,w(DMC)=2%-2.5%,w(GMA)=0.7%,反应温度85℃,反应时间5 h。通过差示扫描量热仪(DSC)、扫描电子显微镜(SEM)和粒度分布分析仪对乳液和纸张性能进行了检测与表征。实验证明,在pH值78条件下,以2%的聚合物乳液进行表面施胶时,可使环压指数、耐破度、抗张指数分别达到16.6 N·m/g、440 kPa、40.6 N·m/g,耐折度10次,与空白样相比均可提高30%以上。 相似文献
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Hamed Mirhosseini Chin Ping Tan Nazimah S.A. Hamid Salmah Yusof Boo Huey Chern 《Food Hydrocolloids》2009
The present work was conducted to investigate the influence of main emulsion components, namely Arabic gum (7–13% w/w), xanthan gum (0.1–0.3% w/w) and orange oil (6–10% w/w) contents on physical stability, viscosity, cloudiness and conductivity of orange beverage emulsion. In this study, 20 orange beverage emulsions were established based on a three-factor central composite design (CCD) involving 8 factorial points, 6 axial points and 6 center points. The main objective of the present study was to determine an optimal concentration level of main emulsion components leading to an optimum orange beverage emulsion with desirable physicochemical properties. In general, all response surface models were significantly (p<0.05) fitted for describing the variability of physical stability, viscosity, conductivity and cloudiness as a nonlinear function of the content of main emulsion components. More than 84% of the variation of physicochemical properties of orange beverage emulsion could be explained as a function of the content of the main beverage emulsion components. In general, the orange oil content appeared to be the most significant (p<0.05) factor influencing all emulsion characteristics studied except for conductivity. From the optimization procedure, the overall optimal region leading to the desirable orange beverage emulsion was predicted to be achieved by the combined level of 13% (w/w) Arabic gum, 0.22% (w/w) xanthan gum and 10% (w/w) orange oil. 相似文献
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目的:探究高速剪切—反相细乳液交联法制备负载氯沙坦淀粉纳米粒的可行性。方法:以氯沙坦为模型药物、三偏磷酸钠为交联剂,考察淀粉溶液浓度、三偏磷酸钠添加量、交联时间和剪切速率对淀粉纳米粒粒径和产率的影响规律,并采用光学显微摄像仪、红外光谱仪、X射线衍射仪对负载氯沙坦淀粉纳米粒进行表征。结果:纳米粒制备的最佳工艺为淀粉溶液浓度15%,三偏磷酸钠添加量25%,交联时间3 h,剪切速率5 000 r/min,该条件下制得的纳米粒粒度最小为755.2 nm,产率可达69.5%;光学显微摄像显示纳米粒形态圆整,颗粒饱满且均为球形;FTIR显示氯沙坦成功负载于淀粉纳米粒中;XRD显示纳米粒以无定形结构存在。结论:高速剪切耦合反相细乳液交联法可以制备出小粒径的载药淀粉纳米粒。 相似文献
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采用半连续种子乳液聚合工艺合成了具有核壳结构的酮肼自交联苯乙烯—丙烯酸酯微皂乳液新型表面施胶剂。加入功能性单体双丙酮丙烯酰胺(DAAM)、己二酰肼(ADH)和丙烯酰胺(AM),选用乳化能力较强的非离子乳化剂OP-10和反应型的阴离子乳化剂A-2405的复合乳化剂体系,并对乳液聚合的工艺参数进行了实验研究,得到最佳反应条件为硬软单体比例3∶7,反应温度70℃,反应时间共7h,乳化剂用量6%,功能性单体用量3%,交联pH值为9。在此条件下可制得稳定、转化率高达99%的苯丙乳液。用作表面施胶剂,涂布后的纸页不仅具有优良的抗水性能,而且具有较高的光泽度。 相似文献