耐水增强丙烯酸酯乳液的研究进展

综述了耐水增强丙烯酸酯乳液改性研究新进展,介绍了采用有机硅、有机氟、环氧树脂和交联单体对丙烯酸酯乳液进行改性的理论依据及发展现状,对核-壳乳液聚合、无皂乳液聚合、互穿网络聚合、有机无机复合乳液聚合等改性方法与机理进行了全面阐述,并展望了耐水增强丙烯酸酯乳液改性的发展趋势。     

自交联含氟丙烯酸酯共聚物的乳液合成与表征

以十二烷基硫酸钠（SDS）和OP-10为乳化剂,甲基丙烯酸十二氟庚酯（DFHM）为含氟单体,双丙酮丙烯酰胺（DAAM）和已二酰肼（ADH）为交联单体,采用饥饿态半连续种子乳液聚合方法,合成了一系列自交联含氟丙烯酸酯共聚物乳液。研究了氟单体对酮肼交联的影响以及交联反应对乳胶膜的表面性能以及力学性能的影响,采用FTIR、TEM、接触角测量仪对乳液及乳胶膜性能进行了表征。研究表明,酮羰基和酰肼的交联反应在室温下可以顺利进行;氟碳基团的引入,使一部分酮羰基被屏蔽,在一定程度上阻碍了交联反应的进行;通过引入氟碳基团可以极大地提高涂膜表面的疏水性,降低涂膜的吸水率,提高涂膜接触角;通过交联反应可以有效地提高氟碳乳液的综合性能,当DFHM为7．5％,DAAM为4％时,交联膜的接触角和吸水率分别达到96．8°和8．5％,拉伸强度为24．8MPa。     

水性油墨用室温交联丙烯酸酯乳液的研究

以甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸为共聚单体,双丙酮丙烯酰胺(DAAM)为功能单体,采用半连续法乳液聚合技术,合成了含有酮羰基的聚丙烯酸酯乳液。以己二酸二酰肼为交联剂,获得的丙烯酸酯乳液在室温贮存时不产生交联反应,而在干燥时由于体系pH值发生变化,在酸的催化下可固化成膜。结果表明,加入3%的DAAM制得的丙烯酸酯乳液,固含量达50%左右,粒径主要分布在68.1 nm左右,且分布范围较窄,室温交联胶膜透明度、光泽度高,成膜速度快,各项性能优异。     

水性油墨用丙烯酸酯乳液的改性研究进展

水性丙烯酸酯乳液在应用中存在成膜温度高、抗回黏性差、耐水性能差、附着力差等缺陷,需对其进行改性。综述了聚氨酯、有机硅、环氧树脂、功能单体、纳米无机材料等对丙烯酸酯乳液性能的改性研究进展及应用状况,并对其应用前景进行了展望。     

甲基丙烯酸乙酰乙酰氧基乙酯改性丙烯酸酯乳液压敏胶的制备及其性能

采用预乳化半连续工艺合成了乙酰乙酰氧基丙烯酸酯压敏胶乳液,以乙二胺为交联剂对其进行了交联改性。探讨了交联单体甲基丙烯酸乙酰乙酰氧基乙酯(AAEM)用量对乳液及胶膜压敏粘接性能的影响。研究结果表明:随着AAEM含量的增加,乳液的粒径变大,乳胶膜耐水性能显著提高。当AAEM用量为单体总量的3%(wt,质量分数)时,所制备的压敏胶带具有很好的压敏粘接性能平衡和耐高温性能。     

室温交联多孔结构分子印迹乳胶膜的制备和性能

以双丙酮丙烯酰胺(DAAM)、丙烯酸(AA)为功能性单体合成了带酮羰基的聚丙烯酸酯核壳乳液,将其与己二酸二酰肼(ADH)、模板分子、致孔剂在室温下交联成膜制备出多孔结构分子印迹乳胶膜(MILM),比较了模板分子与功能单体之间的相互作用,研究了功能单体对MILM分离性能的影响。结果表明,用乳液室温交联成膜法可制备孔隙结构发达的分子印迹膜;三种功能单体与模板分子间相互作用强弱的排序为:ADH体系>DAAM体系>AA体系;ADH、AA和DAAM对MILM交联度的影响均较大,进而影响MILM的渗透性能;与非印迹膜比较,MILM对模板分子表现出选择识别性,分离因子可达到2.0以上。     

氟改性环氧丙烯酸核壳乳液的合成及其涂膜性能

乳液是环保型低表面能海洋防污涂料的重要组分。采用核壳乳液聚合方法合成有机氟改性环氧丙烯酸乳液,探讨了软硬单体质量比、氟单体含量、环氧树脂含量对乳液性能的影响,得到氟改性环氧丙烯酸乳液的最佳配方,并探讨了合成乳液制备的涂料的海洋防污性能。结果表明：软硬单体质量比为1：1,丙烯酸含量为2％,单体核壳质量比为2：3,核玻璃转...     

常温自交联型水性环氧树脂纳米乳液的研究进展

详细介绍了常温自交联型水性环氧树脂纳米乳液的研究进展。首先介绍了环氧树脂水性化的途径及各自的特点,主要包括直接乳化法、相反转乳化法、自乳化法和固化剂乳化法等。介绍了常温自干型水性环氧树脂乳液的实现途径,主要包括羰基与酰肼基团室温自交联、硅氧烷室温自交联、不饱和脂肪酸双键室温自氧化交联、异氰酸酯基团室温自交联、基于Michael加成反应的室温交联、氮丙啶与羧基的室温交联、环状碳酸酯与胺基的室温交联、脂环族环氧基团与羧基的室温交联、金属离子与羧基、磺酸基等螯合作用室温交联、辐射固化型常温自交联、常温多重自交联和包埋固化剂型室温自交联等技术,并详细介绍了其机理。最后,指出了常温自交联型水性环氧树脂乳液目前存在的问题,并对其未来的发展方向进行了展望。     

环境友好型苯丙防锈乳液的改性研究

乳液聚合中引入功能性单体制备一种环境友好型水性防锈苯丙乳液.分别研究考察了具有抗闪蚀能力的功能单体羟基磷酸酯、交联单体丙烯酸羟乙酯、环氧E44以及可室温固化成膜的功能单体乙酰乙酸基甲基丙烯酸乙酯的用量对乳液涂膜及其性能的影响.结果表明,当羟基磷酸酯的用量为单体总量的4％、丙烯酸羟乙酯为10％(相当于单体总量1.5％的-OH)、乙酰乙酸基甲基丙烯酸乙酯AAEM为7％、环氧树脂E-44为6％时,所制备的乳液漆膜的综合性能达到最佳.     

自交联环氧改性丙烯酸酯木器漆乳液的合成

运用自交联和核壳乳液聚合技术,合成了具有多层核壳结构的自交联型环氧改性丙烯酸酯乳液.考察了乳化剂用量、环氧树脂用量、软/硬单体的组成与配比、交联单体的加入量等对乳液和漆膜性能的影响.该乳液用于木制门窗罩面清漆和实色面漆时,可使漆膜硬度提高到≥2H,且柔韧性佳,既具有良好的附着力、优良的抗划伤性、抗回粘性,又具有较佳的耐擦洗性和耐沾污性.     

La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的储氢性能研究

针对两种新型稀土型储氢合金La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2的储氢特性进行研究分析。实验表明,相同温度下,La0.5Y0.5Ni4.8Mn0.1Al0.1和La0.5Y0.5Ni4.8Al0.2合金的PCT曲线基本重合,且都具有优良的吸氢动力学性能;相比之下,后者的滞后系数要小于前者,吸氢量较大,吸氢速率也较快,故其储氢性能较优。300次吸放氢循环实验结果表明,La0.5Y0.5Ni4.8Al0.2合金的吸氢动力学性能虽然略有下降,但抗粉化性能较好。     

Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x取向晶体的结构与磁致伸缩

采用Ｃｚｏｃｈｒａｌｓｋｉ方法生长了Ｄｙ０．６Ｔｂ０．３Ｐｒ０．１（Ｆｅ０．９５Ｍｎ０．０５）ｘ（１．８５≤ｘ≤１．９５）取向合金。所有合金主相为立方Ｌａｖｅｓ相结构,择优取向不完整择优取向的方向与Ｘ的大小有关。研究了沿着这些样品的生长方向的磁致伸缩性能以及磁致伸缩性能与压力之间的关系。     

Thermal Stability of Amorphous Hydride Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45)

The thermal stability of amorphous ternary hydrides Mg_(50)Ni_(50)H_(54) and Mg_(30)Ni_(70)H_(45) and their corre-sponding amorphous binary alloys Mg_(50)Ni_(50) and Mg_(30)Ni_(70) were studied with X-ray diffraction(XRD) and differential scanning calorimetry(DSC). Samples of the amorphous alloys were preparedby mechanical alloying and the amorphous hydrides were obtained by charging the alloys with gas-eous hydrogen at 3.0 MPa and 423 K. It was found that the amorphous hydrides released most oftheir hydrogen before the crystallization of the essentially hydrogen depleted amorphous alloy. Thecrystallization temperature of amorphous Mg_(50)Ni_(50)H_(54) elevated and that of amorphousMg_(30)Ni_(70)H_(45) did not change in relation to the original binary amorphous alloy. This is very excep-tional for amorphous hydrides. The reason for the effects of hydrogen absorption/desorption on thecrystallization of amorphous alloys was discussed.     

Natural Passivity of Amorphous Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 Alloys

The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.     

Acousto-optic interaction in alpha-BaB(2)O(4)and Li(2)B(4)O(7) crystals

Experimental studies and analysis of acousto-optic diffraction in alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are given. Ultrasonic wave velocity, elastic compliance and stiffness coefficients, and piezo-optic and photoelastic coefficients of alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals are determined. The acousto-optic figure of merit has been estimated for different possible geometries of acousto-optic interaction. It is shown that the acousto-optic figures of merit for alpha-BaB(2)O(4) crystals reach the value M(2)=(270 +/- 70) x 10(-15) s(3)/kg for the case of interaction with the slowest ultrasonic wave. The directions of propagation and polarization of those acoustic waves are obtained on the basis of construction of acoustic slowness surfaces. The acousto-optic diffraction is experimentally studied for alpha-BaB(2)O(4) and Li(2)B(4)O(7) crystals.     

Zr65Al7.5Ni10Cu15Co2.5合金的玻璃转变温度

根据Ｚｒ６５Ａｌ７。５Ｎｉ１０Ｃｕ１５Ｃｏ２。５合金的纳米晶，晶体，液体和玻璃比热的测量结果，研究了合金的玻璃转变温度与全金的热力学函数，动力学参数以及加热速度的关系。结果表明，非晶态合金玻璃转变所需转变激活能很小，玻璃转变温度实际上是由于加热速度引起的不同状态的玻璃与液体的热力学平衡温度。     

Nanomechanical characterization of one-step combustion-synthesized Al(4)B(2)O(9) and Al(18)B(4)O(33) nanowires

Two kinds of aluminum borate nanowires, Al(4)B(2)O(9) and Al(18)B(4)O(33), were successfully synthesized by a one-step combustion method through control of the Al:B atomic ratio and synthesis temperature. Both nanowires are single crystalline but have distinguishing growth habits. Nanoindentation tests were performed directly on individual nanowires to reveal their mechanical properties. A 70% reduction in elastic modulus was found in Al(18)B(4)O(33) nanowires compared with their bulk counterpart. Al(18)B(4)O(33) nanowires exhibited higher hardness and elastic modulus than Al(4)B(2)O(9) nanowires.     

Plasma surface treatments of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)

The surfaces of poly(l-lactic acid) (PLLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were modified by oxygen and nitrogen plasma treatments. The physical and chemical surface characteristics were evaluated by contact angle tests, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The plasma treatments caused an increase in both contact angle and roughening, altered the surface morphology, inserted polar groups, and, consequently, enhanced the hydrophilicity for both PLLA and PHBV polymers.     

An SANS Study of Decomposition Kinetics in Amorphous Cu_(12.5)Ni_(10)Zr_(41)Ti_(14)Be_(22.5)

Phase decomposition in amorphous Cu12.5Ni10Zr411Ti14Be22.5 alloy as annealed in the super-cooled liquid range was studied by applying small angle neutron scattering (SANS). As annealed between 600 K and 700 K, the alloy was observed to decompose into two new amorphous phases,with the second phase precipitates embedded in the matrix of the first. Long time annealing of the alloy results in crystallization in addition to evolution of the decomposed microstructure.The kinetic diagram of the decomposition and crystallization for this alloy is given. The second phase precipitates have several nanometers in size and occupy a quite low volume fraction. The decomposition of the supercooled liquid in overall temperature range exhibits the features of spinodal reaction.