室温自交联聚丙烯酸酯乳液的合成及力学性能

利用双丙酮丙烯酰胺与己二酸二酰肼以及甲基丙烯酸缩水甘油醚与乙二胺的反应制备了室温自交联丙烯酸乙酯－丙烯酸丁酯共聚物乳液。动态力学测试结果表明：该共聚物乳液材料为单相体系,其玻璃化温度和阻尼因子依赖于共聚物的组成比和自交联剂的用量。拉伸实验结果表明：随丙烯酸乙酯、双丙酮丙烯酰胺和甲基丙烯酸缩水甘油醚用量的增加,抗拉强度增加。     

室温自交联乳胶漆的制备

采用双丙酮丙烯酰胺(DAAM)、己二酸二酰肼(ADH)和丙烯酸酯类单体制得室温自交联乳液,再由其制备室温自交联乳胶漆。性能检测结果表明:制备的室温自交联乳胶漆的性能优于非交联水性氟碳漆,环保性能优异。     

DAAM在建筑内外墙乳胶漆中的应用

介绍了功能性原料DAAM(双丙酮丙烯酰胺)在室温自交联乳液合成中的应用。它可与固化剂ADH(己二酸二酰肼)配合制成环保型乳胶漆。     

丙烯酸改性双重交联水性聚氨酯乳液的合成研究

采用种子乳液聚合法,以双丙酮丙烯酰胺(DAAM)、丙烯酸羟乙酯(HEA)为功能单体,以己二酸二酰肼(ADH)和含多异氰酸酯基的聚氨酯为固化剂,制备了酮肼、异氰酸酯基双重自交联型聚氨酯-丙烯酸酯复合乳液。研究发现,复合乳液成膜后的交联度可达90%以上,且硬度、耐水、耐丙酮性等性能得到显著提高,具有良好应用性能。     

酮肼交联体系核壳丙烯酸树脂乳液的制备及涂膜性能研究

以双丙酮丙烯酰胺(DAAM)和己二酸二酰肼(ADH)为交联体系,采用核壳结构种子乳液聚合法,合成了室温自交联的核壳丙烯酸树脂乳液。主要考察了交联体系在乳胶粒子的核层和壳层的用量对膜性能的影响,FTIR测试证实在核层、壳层均能发生DAAM-ADH交联反应。通过TEM分析显示,该室温自交联的丙烯酸树脂乳液具有明显的核壳结构。     

自交联水性PVAc乳液胶粘剂的合成及耐水性研究

以醋酸乙烯为原料,DAAM(双丙酮丙烯酰胺)及ADH(己二酰肼)为自交联单体,通过乳液聚合制备了自交联PVAc(聚醋酸乙烯酯)乳液。研究结果表明:当w(DAAM)=2.0%时,胶粘剂湿状剪切强度由未加DAAM改性的1.06 MPa提高至1.36 MPa,胶膜吸水率由改性前的52.36%降至26.81%。红外表征说明聚合物发生了交联反应;透射电镜表征说明合成乳液粒子分布均匀,呈球状或椭球状结构。     

聚氨酯-丙烯酸酯复合乳液的合成及力学性能

采用三乙胺水溶液中和乳化法制备了用己二酸二酰肼封端的PU水分散体,并以此为种子,加入甲基丙烯酸甲酯、丙烯酸丁酯和双丙酮丙烯酰胺用双引发剂进行乳液聚合得到复合乳液。动态力学测试结果表明该复合乳液材料为相分离体系,组分有一定的相容性并依赖于组成比。拉伸实验结果表明随硬组分甲基丙烯酸甲酯含量的增加,抗拉强度增加,材料由橡胶向脆性塑性转变;复合乳液比乳液混合物有较高的强度和伸长率。     

酰肼交联体系对外交联核壳结构苯丙乳液成膜性能的影响

以双丙酮丙烯酰胺(DAAM)和己二酸二酰肼(ADH)为交联单体,采用核壳乳液聚合法对常规苯丙乳液进行改性,制备了室温外交联型苯丙乳液。着重探讨了DAAM/ADH体系对苯丙乳液粒径、稳定性、干燥时间、涂膜强度以及耐水性等影响。研究结果表明:该苯丙乳液具有较明显的核壳结构,并且涂膜具有共价交联结构;当n(ADH)∶n(DAAM)=0.75∶1时,涂膜具有相对最好的综合性能,其铅笔硬度、拉伸强度和耐水性明显提高,并且室温干燥时间也明显缩短。     

室温自交联水性含氟聚氨酯-聚丙烯酸酯复合乳液的制备

采用原位无皂乳液聚合工艺,以丙烯酸单体为溶剂,双丙酮丙烯酰胺（DAAM)和己二酰肼（ADH)为交联体系得到室温自交联水性含氟聚氨酯-聚丙烯酸酯（WFPUA)。通过红外光谱（FT-IR)、透射电镜（TEM)和原子力显微镜（AFM)对聚合物结构进行了表征。同时,研究了含氟量,酮肼交联比例对WFPUA胶膜的性能影响。结果显示,当含氟量为8%、酮肼摩尔比为1：1时,接触角能达到110.5?,吸水率下降至8.8%,抗拉强度从18.12MPa提高至28.55MPa。热重分析表明,酮肼交联的引入有效提高了乳胶膜的热稳定性。     

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。     

丙烯酸酯系胶乳互穿聚合物网络的合成及阻尼性能

以种子乳液聚合法合成了聚苯乙烯／聚丙烯酸乙酯、聚甲基丙烯酸乙酯／聚丙烯酸丁酯的核-壳胶乳互穿聚合物网络(LIPN),分别测试了不同配比LIPN及其共混物的阻尼性能、物理机械性能和吸水性能。结果表明,LIPN共混物是具有阻尼温域宽、阻尼性能优、物理机械性能良好和吸水率较低的阻尼材料,其阻尼性能主要取决于共混组分的性能、配比和内耗能的贡献,并且与共混物的织态结构也密切相关。     

Elastomeric latex domain-interpenetrating polymer networks: Physical and rheological properties

The combination of rubbery and rigid polymers in a multiphase structure using staged emulsion polymerization has yielded materials with properties ranging from reinforced elastomers to high impact plastics. The many different particle morphologies that result from a two-stage latex (TSL) polymerization include core/shell, domain, interpenetrating polymer networks (IPN), and various combinations thereof. The sequence of polymerization, crosslinking, grafting, and composition are among the significant parameters that determine the particle morphology. Elastomeric TSL with soft polyacrylates (PA) as the seed particles and polystyrene (PS) as the second stage, with each stage lightly crosslinked, may yield IPN-microdomain particles. The particle morphology has been elucidated through a combination of microscopy and mechanical property analyses. The significant modulus of elastomeric latex interpenetrating polymer networks (LIPN) results from reinforcement by PS intra-particle microdomains and their significant tensile strength from a strength forming mechanism of PS inter-particle microdomains. The increase in the PA seed crosslinking increases the crosslinked PS (xPS) level of molecular mixing with, and grafting via residual unsaturation to, the crosslinked PA (xPA) network and decreases particle deformnability. At higher xPS concentrations the formation of an xPS-rich shell enhances xPS continuity in the molded material through the partial coalescence of the shells, diminishing the PA continuity, and yielding more PS-like properties. The submicron lightly crosslinked latex particles with these different morphologies flow as a pseudoplastie material through a particle slippage flow mechanism exhibiting neither a Newtonian plateau nor a yield stress at low shear rates. The deformable lightly crosslinked particles with interchangeable PS ties which disintegrate at elevated temperatures retain their identity and regain their shape at the cessation of shear. The LIPN can be processed using standard thermoplastic methods and machinery, with power law constants and shear insensitive flow activation energies that are similar to those of thermoplastics at high levels of shear. Uncrosslinked PS shells around crosslinked PA seed particles, on the other hand, completely coalesce upon molding to form a continuous thermoplastic PS matrix that may essentially flow through molecular deformation.     

胶乳型互穿网络聚合物的研究

综述了胶乳型互穿网络聚合物的研究,着重介绍了合成工,乳胶粒形态结构的影响因素,同时亦对胶乳型互穿网络聚合物的性能作了介绍。     

乳聚丁苯互穿网络型热塑性弹性体的制备

以丁苯胶乳为种子乳液,苯乙烯、甲基丙烯酸甲酯、丙烯腈或它们的混合物的硬单体,用氧化还原引发体系,经种子乳液聚合法同备出复合乳液,絮凝干燥后所得互穿聚合物网络可热塑性反复加工。考察了硬单体的种类和用量、交联剂的种类及用量、反复加工次数对聚合物力学性能的影响。用透射电子显微镜观察了乳胶粒微观形态,结果表明：用混合单体,聚合物力学性能较优,以３５份Ｓｔ＾＋ＭＭＡ为第二单体制备的聚合物的攫断伸长率为４００％,拉伸强度为９．３ＭＰａ,３００％定伸应力为７．６ＭＰ,撕裂强度为７３．９ｋＮ．Ｍ＾－１,邵尔Ａ型硬度为８４。     

Preparation and mechanical properties of thick interlayer composites

A technique is described for producing a thick interlayer composite material composed of an epoxy resin as the matrix and an acrylic-coated fiberglass filler. Through the use of electrostatic forces, the fibers are encapsulated with a controlled, uniform layer(s) of the rubbery acrylic polymer. This coating is then crosslinked. These fibers are subsequently placed into the epoxy matrix, whereby the interfacial properties of the composite become modified. Rapid diffusion of the resin and curing agent results in an interpenetrating network being formed at the glass-epoxy interface. The placement of a uniform latex coating on the fiberglass surface results in improvements in the mechanical properties of the composite. Increases in damping, impact strength, and tensile properties are described.     

Preparation and characterization of PAM/SA tough hydrogels reinforced by IPN technique based on covalent/ionic crosslinking

In order to fabricate tough hydrogels with superior formability, polyacrylamide/sodium alginate (PAM/SA) interpenetrating polymer network (IPN) hydrogels were produced with ionically crosslinked SA interpenetrated in covalently crosslinked PAM. TGA results show that the heat resistance of PAM/SA IPN hydrogel is improved as compared to that of the individual component. Swelling studies indicate that increasing either chemical crosslinker content or ionic crosslinking via adding more N,N′‐methylenebisacrylamide (MBA) or SA results in lower ESR. It is concluded by tensile test that loosely crosslinked PAM coupled with tightly crosslinked SA improve mechanical strength for hydrogels based on covalent/ionic crosslinking. PAM/SA hydrogels via “one‐pot” method can form different complex shapes with mechanical properties comparable to conventional double network (DN) gels. The fracture strength of PAM_0.05/SA₂₀ reaches level of MPa, approaching 2.0 MPa. The work strives to provide method to tune mechanical and physical properties for hydrogels, which is hopefully to guide the design of hydrogel material with desirable properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41342.     

胶乳型互穿聚合物网络

本文概述了胶乳型互穿聚合物网络(LIPN)的概念及制法,形态结构的基本特点,研究方法及影响因素;玻璃化转变行为、物理及力学性能;并对其应用进行了简要介绍。     

Mechanically Stable Dynamic Urea Bond-Based Crosslinked Polymer Blend with Tunable Self-Healable and Physical Properties

Polymer networks crosslinked by reversible noncovalent crosslinks have been applied in self-healing and recyclable sustainable materials but result in limited mechanical strength. Herein, a crosslinked polymer blend that is based on a urethane–arcylate system with a combination of reversibly noncovalent intrachain and interchain hydrogen bonds and dynamically covalent urea bonds is developed through facile in situ photo-induced copolymerization. An essential step is the introduction of a flexibly dynamic crosslinker bearing robustly hindered urea bonds and urethane–urea structures into the network, which endows the dynamic network with a synergy of mechanical robustness and desirable self-healing ability. The dynamic networks exhibit rapid self-healing at mild conditions (70 °C, 30 min), extreme toughness (≈34.76 MJ m⁻³), high tensile strength (≈7.78 MPa), superior stretchability (≈932%), long-term stability, recyclability, and weldability. More importantly, the mechanical and self-healing properties of the resultant materials can be fine-tuned by adjusting the dynamic crosslinker content. These superior properties are attributed to the dynamic reversibility of hydrogen bonds and urea bonds as monitored by rheological tests. The extremely facile fabrication approach and superior properties of the resulting self-healing polymers can find applications in sustainable smart materials and self-healing conductive sensors.