含双丙酮丙烯酰胺(DAAM)的水性乳液的制备与性能研究

通过预乳化乳液聚合工艺,合成了含官能团单体双丙酮丙烯酰胺(DAAM)、丙烯酰胺、N-甲基丙烯酰胺(NMA)的自交联丙烯酸酯乳液。实验结果表明,DAAM用量的增加对乳液涂膜的硬度有影响,而涂膜的耐水性随NMA用量增加有显著提高,在DAAM用量为单体含量的2％,NMA用量为单体含量的4％时,涂膜的铅笔划痕硬度达2H,耐水性达96h以上。     

自交联封闭性乳液的合成与性能

以双丙酮丙烯酰胺（DAAM）、甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）和甲基丙烯酸（MAA）为共聚单体,采用半连续种子乳液聚合工艺合成自交联封闭性聚丙烯酸酯乳液（PAE）,考察了DAAM和复合乳化剂对乳液聚合稳定性以及涂膜性能的影响。研究发现：随着DAAM含量的增加,乳液聚合稳定性下降,粒径增大,涂膜的耐介质性能和交联度提高,合适的DAAM加入量为总单体质量的3.0%,DAAM和己二酰肼(ADH)的最佳摩尔比为2∶1。采用SDBS+OP-10+OP-40为复合乳化剂体系,选用乳化剂的含量为2.35%,阴/非离子乳化剂质量比为1∶1.25;复合乳化剂在种子、核、壳比例为1.5∶1∶2,制备的乳液具有较好的聚合稳定性（乳液凝胶率低和单体转化率高）,乳液耐电解质（钙离子）稳定性好,涂膜具有优异的封闭性。傅里叶红外光谱（FTIR）表明在涂膜形成过程中DAAM的酮羰基与ADH的酰肼基反应生成腙（C=N）,TEM分析显示乳液的乳胶粒子呈核壳结构,TGA分析发现DAAM改性的PAE降低了涂膜的热稳定性。     

Electron‐beam‐induced crosslinking of natural rubber/acrylonitrile–butadiene rubber latex blends in the presence of ethoxylated pentaerythritol tetraacrylate used as a crosslinking promoter

A natural rubber latex, an acrylonitrile–butadiene rubber latex, and their 50: 50 blends were exposed to an electron beam in air. A polyfunctional monomer, ethoxylated pentaerythritol tetraacrylate, was used as a crosslinking promoter. Cast films from the irradiated systems were characterized for their gel contents, swelling properties, and tensile strength. An increase in the radiation dose from 0 to 500 kGy resulted in increased crosslinking, as measured by an increase in the gel content and better swelling resistance. The effect of the polyfunctional monomer, ethoxylated pentaerythritol tetraacrylate, as a crosslinking promoter was studied with infrared spectros copy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1206–1214, 2007     

室温自交联丙烯酸酯乳液的合成及性能研究

采用半连续种子乳液聚合法,改性异构十三醇醚（ H-606）与十二烷基硫酸钠（SDS）复配,以甲基丙烯酸（MAA）为功能单体,叔碳酸乙烯酯（VeoVa10）为改性单体,乙酰乙酸烯丙酯（ AAA）与己二胺（ HDA）为复配交联剂,合成了 AAA-HDA/VeoVa10改性丙烯酸酯乳液。研究了 AAA加料时间、 AAA-HDA配比、 AAA与 VeoVa10用量对乳液性能的影响。结果表明： AAA参与共聚合,并在室温下与 HDA发生失水自交联反应;当 AAA进料时间为单体滴加 20%时、 AAA用量为总单体质量的 2%、（AAA）∶m（HDA）=5∶2、VeoVa10用量 10%时,乳胶膜吸水率从 14. 76%降至 8. 13%,拉伸强度达到2.90mMPa,断裂伸长率为 493. 86%,乳胶膜耐水白能力大幅提高（ΔL由 88. 5降至 7. 1）。     

脲基功能单体对丙烯酸酯PSA乳液性能的影响

以丙烯酸酯类单体为主要原料,将脲基功能单体[MAEEU(甲基丙烯酰胺乙基乙撑脲)]和DAAM(双丙酮丙烯酰胺)引入体系中,采用半连续乳液聚合法制备改性丙烯酸酯PSA(压敏胶)乳液。研究结果表明:MAEEU在乳液聚合后期加入且w(MAEEU)=3%时,PSA乳液的综合性能(如初粘力、持粘力、剥离强度和耐水性等)相对最好;此时PSA的Tg(玻璃化转变温度)从-36.47℃升至-8.95℃,说明在乳液成膜过程中MAEEU和DAAM可发生交联反应,并且交联效果明显;脲基功能单体的使用为提高乳液型PSA性能的研究提供了新的方法 。     

水性丙烯酸酯乳液的合成及性能研究

以双丙酮丙烯酰胺（DAAM）为功能性单体,采用预乳化半连续种子乳液聚合法合成水性丙烯酸酯乳液,添加己二酸二酰肼（ADH）为交联剂,构成室温自交联体系。考察了DAAM、ADH用量对乳液及其乳胶膜性能的影响。用傅里叶红外光谱仪（FT-IR）对交联反应进行了表征。通过差示扫描量热法、力学性能和耐溶剂性能的测试等方法研究了乳液和乳胶膜的性能。结果表明,当DAAM用量为2.4%~3.5%,ADH与DAAM的当量比为1~1.2时,乳液和乳胶膜的综合性能较好。     

Effects of gamma radiation on the dynamic mechanical and swelling behavior of styrene butadiene block and random copolymers

The physical structure of a number of styrene-butadiene copolymers were investigated via dynamic mechanical and swelling studies on uncrosslinked and gamma-radiation cross-linked films that had initially been solvent cast from toluene or methyl ethyl ketone. The mechanical behavior of these films before and after crosslinking was found to depend on the material history as well as the chemical structure of the copolymer, in agreement with observations made by other experimental techniques. A simple morphological interpretation was given to the dynamic mechanical spectra as a function of radiation dosage and a limited discussion of the swelling behavior is included.     

The diacetone acrylamide crosslinking reaction and its control of core‐shell polyacrylate latices at ambient temperature

Self crosslinkable core‐shell polyacrylate latices (PAs) cured at ambient temperature were synthesized by semicontinuous‐seeded emulsion polymerization with diacetone acrylamide (DAAM) and adipic dihydrazide (ADH) as crosslinkable monomers. The influences of DAAM monomer mass content, neutralizer, and curing temperature on the properties of self crosslinkable core‐shell latices and the keto‐hydrazide crosslinking were discussed. The spectroscopic techniques such as Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), atomic force microscopy (AFM), transmission electron microscopy (TEM), and contact angle instruments were used to determine the structure and properties of PAs. The water evaporating rate during the film‐forming process of self crosslinkable core‐shell latices was also investigated. FTIR analyses demonstrate that the keto‐hydrazide crosslinking reaction does not occur in the latex environment but occurs at ambient temperature with the evaporation of water during the film‐forming process. The results of DSC show that the core‐shell crosslinkable PAs have two glass transition temperatures (T_g), and T_gs of crosslinked film are higher than that of non crosslinked fim. Moreover, the keto‐hydrazide reaction is found to be acid catalyzed and favored by the loss of water and the simultaneous decrease in pH arising from the evaporation of ammonia or amines during film‐forming process. Hence, in the volatile ammonia or amines neutralized latices, the latex pH value adjusted to 7–8, which not only ensure the crosslinkable latex with good storage stability but also obtain a coating film with excellent performances by introducing the keto‐hydrazine crosslinking reaction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

中空聚合物微球的制备——种子及核乳胶粒的制备

为了制得具有中空结构的聚合物微球,首先以十二烷基苯磺酸钠(SDBS)为乳化剂,在其用量低于CMC的条件下,进行甲基丙烯酸甲酯(MMA)、甲基丙烯酸(MAA)和丙烯酸丁酯(BA)的乳液聚合,制备了带羧基的种子乳胶粒.然后采用MMA、MAA和二乙烯基苯为单体进行种子乳液聚合,制备了轻度交联的带羧基的核乳胶粒.该核乳胶粒经过核-壳乳液聚合和适当的碱处理工艺就可成为具有中空结构的聚合物微球.采用粒度仪测定了乳胶粒的直径及其分布,采用TEM对乳胶粒结构形态进行了表征.研究了种子及核乳胶粒制备过程中单体加料方式、乳化剂用量及羧基单体种类等因素对聚合稳定性、乳胶粒直径及其分布以及最终的中空聚合物微球结构形态的影响,确定了制备种子及核乳胶粒的最佳工艺条件.在制备种子阶段,SDBS用量为单体总量的0.5%,采用一次性加入单体的进料工艺;在核乳胶粒制备阶段,以MAA为羧基单体,所有单体采用"饥饿式"加料,半连续补加乳化剂并使乳化剂用量为核单体总量的0.15%时可保持聚合稳定性并保证无新乳胶粒生成.     

室温交联聚丙烯酸酯乳胶膜的制备及其渗透性能

以双丙酮丙烯酰胺（DAAM）为官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）在室温下交联制备了聚丙烯酸酯多孔乳胶膜,考察了乳液壳层组成、ADH用量、致孔剂用量及种类对乳胶膜渗透性能的影响。研究结果表明,当壳层组成BA/(MMA+AA+DAAM)质量比为2.5/2.5时,乳胶粒子没有完全变形,粒子间相互融接堆积,结合致孔剂的作用,形成了内部呈疏松多孔结构的乳胶膜,膜的渗透量较高;研究进一步揭示,限制大分子链段的热运动有利于维持乳胶膜的多孔结构,从而获得较高的渗透量;此外,发现以葡萄糖、聚乙二醇300（PEG300）为致孔剂时可使乳胶膜获得较高的渗透量。     

Dynamic mechanical study on multilayer core–shell latex for damping applications

Multilayer core–shell poly (styrene-butyl acrylate) latex particles were synthesized via semi-continuous emulsion polymerization, and the process was monitored by a dynamic laser scattering (DLS). The layers of the latex particles were designed to have progressively decreasing glass transition temperatures (T_g) from the core (layer 1) to the outmost shell (layer 4), which was achieved by varying the mass ratio of butyl acrylate (BA) to styrene (St) in the synthesis of each layer. Divinylbenzene (DVB) was added as the crosslinking agent in each layer except for the outmost layer in order to ensure that a continuous film can be formed at room temperature. The damping properties of the formed films as well as the influences of synthesis variables, including the content of DVB added in the internal layers (i.e., layers 1, 2, and 3), the total mass ratio and sequence between layers 3 and 4, and the T_g of each layer were studied by dynamic mechanical analysis (DMA). The results showed that four-layer core–shell latex particles with proper DVB content in each layer exhibited the best damping properties, with a broad effective damping range (tan δ > 0.3) ranging from −12.0 °C to 97.2 °C. The widening of the damping peak can be explained by the formation of a gradient IPN structure in latex particles. Furthermore, the morphology of the formed films was studied by AFM in tapping mode.     

N-羟甲基丙烯酰胺对硅丙乳液及乳胶膜性能的影响

将N-羟甲基丙烯酰胺(NMA)、端乙烯基聚硅氧烷大单体与丙烯酸酯类单体进行乳液共聚合反应,制备了稳定的自交联型的硅丙乳液。通过聚合过程的动力学,聚合稳定性,乳胶粒的粒径大小和分布,以及乳胶膜的耐水性和力学性能测试,结合乳胶粒的微观形态和胶膜的红外光谱和DSC分析,讨论了NMA的引入及聚合方法对硅丙乳液和乳胶膜性能的影响。结果表明,在NMA适量加入的情况下,聚合反应速度加快,聚合稳定性提高,乳胶膜的耐水性增强,并使乳胶膜的力学性能也得到较大的提高。     

全氟内交联型聚醋酸乙烯酯乳液的制备及其膜耐水性研究

为了大幅度提高聚醋酸乙烯酯的耐水性,本文采用全氟烷基乙基丙烯酸酯单体(FA)对其进行改性,并通过羟甲基丙烯酰胺(HMA)进行内交联,以醋酸乙烯酯(VAc)、丙烯酸(AA)、丙烯酸丁酯(BA)为主要单体,以聚乙烯醇(PVA)为保护胶体,通过无皂乳液聚合法制备了全氟内交联型聚醋酸乙烯酯乳液。同时考察了全氟单体和交联剂用量比对乳液粒径、流变性和涂膜耐水性的影响,并确定了它们的最适宜条件。研究结果表明,乳液为非牛顿流体,且具有一定的假塑性和触变性,表观黏度随切变速率的变化规律呈现切力变稀特征,当全氟单体用量为6%和交联剂用量为2.5%时,全氟内交联型聚醋酸乙烯酯膜具有良好的稳定性和耐水性。     

双丙酮丙烯酰胺的制备及应用研究进展

双丙酮丙烯酰胺(DAAM)是一种新型的功能单体,在化工领域中占有重要地位。文章综述了DAAM的制备技术和近年来在涂料等领域中的应用进展。双丙酮丙烯酰胺可用二丙酮醇和丙烯腈、丙烯酰胺和二丙酮醇、丙烯酰胺和异丙烯基丙酮为原料,强酸或杂多酸为催化剂制得。由于DAAM分子具有多功能基团的独特构型,因而化学性质非常活泼,具有许多优良性质,能进行多种反应,如聚合反应、交联反应、加成反应等,并以其良好的水溶性、保湿性、吸水性等特性,在涂料、日化用品、感光树脂助剂、粘合剂、环氧树脂固化剂、替代明胶、医用材料、聚酯树脂交联剂和纸张增强剂等领域的应用日趋广泛。本文最后展望了其今后的研究方向和发展趋势。     

The effects of latex coalescence and interfacial crosslinking on the mechanical properties of latex films

The effects of latex coalescence and interfacial crosslinking on the mechanical properties of latex films were extensively investigated by means of several series of model latexes with varying backbone polymer crosslinking density and interfacial crosslinking functional groups. It was found that the tensile strength of crosslinked model latex films increased with increasing gel content (i.e. crosslinking density) of latex backbone polymers up to about 75% and then decreased with further increase in gel, while their elongation at break steadily decreased with increasing gel content. These findings showed that latex particle coalescence was retarded above a gel content of about 75% so that the limited coalescence of latex particles containing gel contents higher than 75% prevented the tensile strength of crosslinked latex films from increasing by further crosslinking the latex backbone polymers. This was contrary to the theory of rubber elasticity that the tensile strength increases with increasing molecular weight and crosslinking density. This limitation was found to be overcome by the interfacial crosslinking among latex particles during film formation and curing. This paper will discuss the effects of both latex backbone polymer and interfacial crosslinking on latex film properties. It will also discuss the development of self-curable latex blends and structured latexes containing co-reactive groups: oxazoline and carboxylic groups.     

聚合工艺对室温交联丙烯酸乳胶漆性能的影响

研究了无皂、微皂和常规二种乳液聚合工艺对以双丙酮丙烯酰胺(DAAM)为交联单体、己二酰肼为固化剂的室温交联丙烯酸乳胶漆性能的影响。研究表明：采用常规乳液聚合涂膜的光泽较高，而采用无皂和微皂乳液聚合涂膜的耐水性较好，涂料的起泡性较低。     

核壳结构丙烯酸酯乳液的合成与研究

采用种子乳液聚合方法合成了一种新型的核壳结构丙烯酸酯乳液。研究了核壳比例、乳化剂种类与用量、种子乳液的稳定时间和交联剂用量等因素对乳液性能的影响,以及对乳胶粒子的多分散指数的影响,优化了合成工艺。结果发现加入特殊单体能够改善成膜物的耐水性,并因此确定了特殊单体的比例。     

新型醋丙水性干法复膜胶的研制

介绍了一种利用半连续乳液聚合工艺制备水性复膜胶的方法。以阴非复合型乳化剂CO-459为乳化剂,以丙烯酸丁酯、醋酸乙烯为主要单体,同时添加AA、HPA、NMAM、DAAM和ADH等作为功能单体参与共聚,并在此基础上添加同一乳化体系的苯丙乳液,提高产品的性能。重点讨论了单体、乳化剂、反应温度和苯丙乳液的加入对醋丙乳液的聚合及性能的影响。实验结果表明,单体BA∶VAC=1∶1~1.5、功能单体用量为总投料量的2.1%、乳化剂用量为总投料量的1.1%、反应温度为80~85℃、苯丙乳液添加量为醋丙乳液的30%,制得的乳液成本低廉、性能经实际上机使用满足客户的要求。     

室温自交联型丙烯酸树脂-明胶复合乳液的制备及涂膜性能

以乙酰乙酸基甲基丙烯酸乙酯(AAEM)为功能单体,通过半连续种子乳液聚合制备出侧链含活性酮羰基的丙烯酸树脂乳液(PA),加入明胶,可得到稳定性高且具有室温自交联功能的丙烯酸树脂-明胶复合乳液(PAG)。采用红外光谱(FTIR)对PA-G膜中的交联结构进行表征,用接触角测定仪(CA)、原子力显微镜(AFM)、差示量热扫描仪(DSC)等对PA-G膜进行性能测试。结果表明,这种PA-G复合乳液的涂膜在硬度、热学性能、力学性能及抗水性等方面表现出不同特点,硬度和玻璃化转变温度得到显著提高,抗张强度大幅度提高,但断裂伸长率均有所降低;通过AAEM-明胶之间的适度交联可赋予PA-G膜良好的抗水性,且其表面相对粗糙度变化不大。     

Preparation of resistant starch/poly(vinyl alcohol) blend films with added plasticizer and crosslinking agents

We report on the physical properties of films synthesized with native corn starch (NCS) and resistant starch (RS4) prepared with NCS. NCS and RS4/poly(vinyl alcohol) (PVA) blend films were synthesized with a mixing process and casting method. Glycerol (GL) and citric acid (CA) were used as additives. Glutaraldehyde (GLU) was used as a crosslinking agent of the films. RS4 was synthesized with sodium trimetaphosphate and sodium tripolyphosphate as a crosslinker. Then, the RS4 thus synthesized was confirmed by the pancreatin–gravimetry method, swelling power, differential scanning calorimetry, and X‐ray diffraction. The tensile strength, elongation, swelling behavior, and solubility of the films were measured. The results of the measurements indicated that the RS4‐added film was better than the NCS‐added film. In particular, the RS4/PVA blend film with CA as an additive showed physical properties superior to those of the other films. Also, the physical properties with GLU added as a crosslinking agent to the films were investigated. With increasing GLU contents, the tensile strength increased but the elongation, swelling behavior, and solubility values of the GL‐added and CA‐added films decreased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007