苯乙烯改性丙烯酸酯乳液压敏胶的研制

以丙烯酸丁酯、甲基丙烯酸甲酯、苯乙烯、丙烯酸-2-羟乙酯、丙烯酸为反应单体,十二烷基硫酸钠与聚乙二醇辛基苯基醚按质量比2：1组成复合乳化剂,过硫酸钾为引发剂,采用乳液聚合法,制备了苯乙烯改性丙烯酸酯乳液型压敏胶;对乳液型压敏胶进行了粒度分布、初粘性、180°剥离强度测试。研究结果表明,在反应温度为83±2℃、反应时间为6h、复合乳化剂用量为单体总质量的3～5％、引发剂用量为单体总质量的0．6～0．8％、单体质量比BA：MMA：St：HEA：AA为80：5：10：2：3的工艺条件下,可制得粒径分布窄、平均粒径小、初粘性好、剥离强度高的乳液型压敏胶。     

聚丙烯酸酯乳液压敏胶可剥离性能的研究

以丙烯酸丁酯、甲基丙烯酸甲酯等为原料,制备了一种具有可剥离效果的聚丙烯酸酯乳液压敏胶。主要考察了聚合物的玻璃化转变温度(T_g)、复合乳化剂十二烷基硫酸钠/烷基酚聚氧乙烯醚(SDS/OP-10)及交联剂乙酰乙酸基甲基丙烯酸乙酯(AAEM)对压敏胶综合性能及可剥离性能的影响。实验结果表明,在设计T_g=-25℃,乳化剂用量为2.5%(以单体总质量计,下同),AAEM用量为1%时,所制备的压敏胶在不同基材上粘结强度适中,可达到多次剥离无残胶、耐老化性好的效果。     

水性油墨用聚酰胺树脂乳液的研究制备

采用醇溶性聚酰胺树脂与甲基丙烯酸甲酯（MMA）、丙烯酸（AA）反应,合成水性油墨用接枝共聚物-自乳化聚酰胺树脂,并结合相反转技术制备水性聚酰胺乳液。研究了单体配比、溶剂选择及其用量、引发剂用量对聚合工艺和乳液性能的影响。对影响乳液性能的因素如聚合物相对分子质量等各种因素进行了分析和表征。     

外交联型多元共聚物乳液的研制

甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸2－乙基己酯、丙烯酸和甲基丙烯酸β-羟乙酯等单体经乳液共聚制得外交联型多元共聚物乳液，讨论了乳化剂配比及用量，引发剂用量，功能单体用量，软硬单体的配比对乳液聚合反应及涂膜性能的影响，确定了适宜的反应条件及配方。     

丙烯酸改性氯醚树脂乳液的合成研究

采用溶液聚合法,以丙烯酸(AA)、丙烯酸丁酯(BA)和甲基丙烯酸甲酯(MMA)为混合单体,与氯醚树脂(VC-IBVE)进行接枝共聚;用中和剂三乙胺(TEA)与接枝反应产物中和成盐,得到水性丙烯酸改性氯醚树脂乳液.讨论了引发剂浓度对该体系接枝率的影响,重点研究了丙烯酸类单体用量以及混合单体中丙烯酸和丙烯酸丁酯的含量对改性乳液性能的影响.结果表明:丙烯酸类单体用量为50％,混合单体中丙烯酸和丙烯酸丁酯的含量分别为9％～11％和40％时,制得的改性乳液具有良好的稳定性、耐盐水性和优异的附着力.并用红外光谱(FT-IR)和透射电子显微镜表征(TEM)了此改性乳液.     

单组分溶剂型丙烯酸酯压敏胶的研制

采用丙烯酸异辛酯、丙烯酸丁酯、丙烯酸、醋酸乙烯酯、甲基丙烯酸甲酯和甲基丙烯酸缩水甘油酯等为原料,通过接枝聚合制备了一种单组分溶剂型丙烯酸酯压敏胶。探讨了干燥时间和温度、交联剂用量对该压敏胶性能的影响。考查了加入交联剂后压敏胶及其产品的性能稳定性。结果表明,当交联剂用量为0.6%时,可以获得综合性能优良、贮存稳定的单组分压敏胶。通过应用于压敏胶标签实例进一步验证了此压敏胶部分生产工艺及产品性能指标。     

保护胶带用高剥离强度乳液压敏胶的研究

以丙烯酸丁酯(BA)、丙烯酸异辛酯(2-EHA)、甲基丙烯酸甲酯(MMA)、苯乙烯(St)、丙烯酸(AA)、丙烯酸羟丙酯(HPA)为原料进行乳液共聚,合成了保护膜用丙烯酸酯乳液压敏胶。讨论了乳化剂种类及用量、引发剂及缓冲剂用量、聚合温度、聚合时间、种子乳液用量对压敏胶性能的影响。结果表明,合成的压敏胶具有较高的剥离强度和初粘性,同时具有较好的耐高温高湿老化性能。     

环氧-丙烯酸酯乳液的研制

以甲基丙烯酸甲酯为硬单体 ,丙烯酸丁酯、丙烯酸 - 2 -乙基己酯为软单体 ,丙烯酸、甲基丙烯酸β-羟乙酯为功能单体 ,环氧树脂为改性剂 ,通过乳液共聚合制备环氧 -丙烯酸酯乳液。讨论了乳化剂配比、用量 ,引发剂用量 ,反应温度 ,环氧树脂用量、环氧树脂的环氧值 ,以及软硬单体的配比对乳液聚合反应及涂膜性能的影响 ,确定了适宜的反应条件及较佳的配方。     

乳化剂对乳液型压敏胶的影响

简述了乳化剂对乳液型压敏胶聚合物，粘性能和耐水性的影响，并通过控制乳化剂用量、使用反应性乳化剂、加入适量增粘剂的或者使乳液聚合物部分交联来提高乳液型压敏胶的性能。     

核壳型丙烯酸酯乳液的制备与性能研究

采用甲基丙烯酸甲酯／丙烯酸丁酯作复合单体,丙烯酸为功能单体,通过预乳化半连续种子乳液聚合工艺合成了核壳型丙烯酸酯乳液,讨论了反应温度、乳化剂用量、核壳单体质量比以及丙烯酸加入量对乳液性能以及漆膜力学性能的影响,并用TEM对乳胶粒子进行了表征。结果表明：采用预乳化半连续滴加法,当复合乳化剂SDS与OP-10质量比为2：1且总用量为4％,核、壳层中甲基丙烯酸甲酯与丙烯酸丁酯的质量比分别为3：7和4：1,核壳总单体质量比为1：1,丙烯酸质量分数为4％,核层和壳层反应温度分别为70℃和80％时,可以合成黏度适中、乳胶粒粒径分布均匀、稳定性好和漆膜力学性能优良的核壳型丙烯酸酯乳液。     

氟碳铝型材保护膜用压敏胶的制备与性能

以丙烯酸丁酯(BA)和丙烯酸异辛酯(2-EHA)为软单体、甲基丙烯酸甲酯(MMA)为硬单体、丙烯酸(AA)和丙烯酸羟丙酯(HPA)为功能单体,采用降低PSA(压敏胶)的Tg(玻璃化转变温度)和预乳化半连续乳液聚合法合成了丙烯酸酯PSA乳液。研究结果表明:当m(软单体)∶m(硬单体)∶m(功能单体)=90∶5∶5、m(BA)∶m(2-EHA)=1∶2、w(AA)=1.0%、w(HPA)=5%、w(缓冲剂)=0.25%、w(引发剂)=w(复合乳化剂)=0.6%且m(阴离子型乳化剂)∶m(非离子型乳化剂)=1∶1时,PSA乳液的综合性能相对最好,用该PSA制成的保护膜对氟碳铝型材具有良好的附着力,并且其耐湿热老化性能和耐热老化性能俱佳。     

Radiation grafting of methyl methacrylate monomer on natural rubber latex

A method of radiation grafting of methyl methacrylate (MMA) monomer on natural rubber (NR) latex has been studied. The irradiation dose in radiation emulsion polymerization of MMA monomer was lower compared to the irradiation dose for grafting of MMA monomer on NR latex, in order to obtain the same degree of conversion. This is due to the size of the rubber particles which are quite large and, hence, not sufficient to ensure an ideal emulsion polymerization. The irradiation dose for radiation grafting of MMA monomer on latex was around 300 krad to obtain a 75% degree of conversion. However, this irradiation dose was lower compared to the irradation dose for bulk polymerization of MMA monomer, in order to obtain the same degree of conversion. This is due to the gel effect in the viscous media. Radiation grafting of MMA monomer on NR latex does not influence the pH of the latex, but influences the viscosity significantly. The viscosity of the NR latex increased with an increase in irradiation dose, due to the increase of the total solid content in the latex. The MMA monomer converted to P-MMA in NR latex was largely grafted on the NR, or at least insoluble in a solvent for P-MMA, such as acetone or toluene. The hardness of the pure gum vulcanizate with an increase in the degree of grafting or P-MMA content, but the other physical properties, such as tensile strength, modulus, elongation at break, and thermal stability, were not greatly influenced by the degree of grafting.     

Adhesion performance of PSA–clay nano-composites by the in-situ polymerization and mechanical blending

The synthesis and characterization of acrylic polymer/Na-montmorillonite (Na-MMT) clay nano-composites pressure sensitive adhesives (PSA) are researched. The PSA/clay nano-composites were synthesized by in-situ emulsion polymerization and mechanical blending. And then, different amounts of nanoclay were dispersed in 2-ethylhexyl acrylate (2-EHA)/n-butyl acrylate (BA)/methyl methacylate (MMA)/acrylic acid (AA) monomer mixture, which was synthesized using in-situ emulsion polymerization technique. Morphological observation was carried out using X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). Viscoelastic properties of PSA/clay nano-composites were analyzed using advanced rheometric expansion system (ARES). The adhesion performances of synthesized PSA/clay nano-composites were determined by measurements of peel strength, probe tack and shear adhesion failure temperature.     

Dynamic Mechanical Properties and Adhesive Joint Strengths of Emulsion Polymers Produced by Power Feed Technique. II. Chemical Structure of Grafted Power Feed Polymer

Power feed copolymers were synthesized using styrene and n-butyl acrylate through a non-uniform feeding emulsion polymerization. Poly(vinyl alcohol) (PVA) was used as a protective colloid, onto which vinyl monomers were grafted. With the increase of PVA, grafting was also increased. Feeding method did not affect grafting nor grafting efficiency to a great extent. However, the amount of initiator had a negative correlation against grafting or grafting efficiency. From NMR spectroscopy, it was known that n-butyl acrylate monomer grafted onto PVA rather than copolymerized with styrene monomer. In order to increase the cohesive strengths of each phase, grafting was introduced to the power feed polymerization. In these cases, the chemical structure of grafted power feed polymer was investigated.     

Dynamic Mechanical Properties and Adhesive Joint Strengths of Emulsion Polymers Produced by Power Feed Technique. II. Chemical Structure of Grafted Power Feed Polymer

Power feed copolymers were synthesized using styrene and n-butyl acrylate through a non-uniform feeding emulsion polymerization. Poly(vinyl alcohol) (PVA) was used as a protective colloid, onto which vinyl monomers were grafted. With the increase of PVA, grafting was also increased. Feeding method did not affect grafting nor grafting efficiency to a great extent. However, the amount of initiator had a negative correlation against grafting or grafting efficiency. From NMR spectroscopy, it was known that n-butyl acrylate monomer grafted onto PVA rather than copolymerized with styrene monomer. In order to increase the cohesive strengths of each phase, grafting was introduced to the power feed polymerization. In these cases, the chemical structure of grafted power feed polymer was investigated.     

结合磷阻燃型苯丙共聚乳液胶粘剂的合成及性能研究

以苯乙烯(St)、丙烯酸丁酯(BA)、丙烯酸乙酯(EA)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)和含磷单体为共聚单体,采用预乳化种子乳液聚合法制备PSA(结合磷型苯丙共聚乳液胶粘剂),并在PSA中添加少量无机阻燃剂APP(聚磷酸铵)制备CPSA(复合型阻燃胶粘剂)。系统研究了含磷单体和APP含量对乳液稳定性、胶膜剥离强度、涂层阻燃性和热性能等影响。结果表明:当m(St+BA+EA+MMA+AA)=40 g、m(St)∶m(BA)∶m(EA)∶m(MMA)∶m(AA)=16∶90∶60∶24∶5、w(含磷单体)=4%和w(APP)=12%(相对于单体总质量而言)时,可制成稳定性、剥离强度和阻燃性能俱佳的CPSA。     

Polymer–leather composites. II. Kinetics of the deposition of selected acrylate monomers by polymerization into chrome-tanned cattlehide

Limited kinetic information on a convenient process for depositing polymer in 5-oz cattlehide is presented in this article. The work includes a systematic study of the total polymerization rate and of the derived rates of deposition into the fibrous matrix, of bound polymer formation, and of polymer production in the external aqueous phase (the float) for three acrylic monomers. The monomers used, with a persulfate–bisulfite redox initiating system at 27°C, were methyl methacrylate (MMA), n-butyl acrylate (BA) and a fixed mixture of n-butyl acrylate and methyl methacrylate (BA + MMA). The effects of the reaction variables on rate, as measured by their intensity exponents, were not in agreement with a rate expression proposed to describe grafting in homogeneous polymerization, nor were they wholly compatible with classical and modified Smith–Ewart theories for heterogeneous emulsion polymerization. The experimental behavior, however, was in harmony with self-nucleation in the aqueous phase. Exponential orders of dependence were initiator > 0.5 (MMA, 0.72; BA + MMA, 0.66); monomer, zero; surfactant, ～0.5. The approximately 0.6 order dependence (MMA, 0.9) on leather amount was shown to be largely apparent and to decline as total polymerization proceeded. Thus a dominant grafting reaction was not supported. In support of this conclusion, simple impregnation of the matrix with preformed emulsion polymer yielded the same amount of bound polymer as that formed in situ. It was concluded that monomer is initiated largely from active centers formed initially near fibers or fibrils to form embryo polymer particles, which join penetrating swollen polymer particles and become unstable. These nucleate a polymer front, containing occluded radicals, which grows by diffusion regulated transport of monomer to complete deposition.     

Graft polymerization of methyl methacrylate onto short leather fibers

Summary In this work, the graft polymerization of methyl methacrylate (MMA) monomer onto short leather fibers (SLF) was investigated as a function of the monomer/leather fiber ratio. This chemical modification was made by aqueous emulsion polymerization initiated by a redox system. The effect of' the monomer concentration on the grafting parameters (deposited and grafted polymer, as well as grafting efficiency) were determined. Composites formulated with SLF without chemical modification have showed lower tensile and impact properties in comparison with composites formulated with treated fibers. However, the elongation at break values for both systems remained similar as the MMA content changed. The morphology of SLF grafted with MMA was examined by both optical light microscopy (OLM) and scanning electron microscopy (SEM). Micrographs have shown polymer deposition on individual fibers and bundles of SLF. They have also revealed that PMMA may interpenetrate the SLF network and be deposited in large and coarse aggregates around individual fibers, but without occupation of the free space in the fiber net. Received: 1 October 1998/Revised version: 25 January 1999/Accepted: 25 January 1999     

Effect of propyleneimine external cross-linker on the properties of acrylate latex pressure sensitive adhesives

Acrylate pressure sensitive adhesive (PSA) latexes were synthesized via a starved monomer seeded semi-batch emulsion polymerization process with butyl acrylate (BA), methyl methacrylate (MMA), acrylic acid (AA) and 2-hydroxyethyl acrylate (HEA). These PSA polymers were then cross-linked with trifunctional propyleneimine external cross-linker (SAC-100) to study the cross-linking reaction between carboxylic group of the polymer chain and cross-linking agent. It was found that cross-linking provided a significant influence on the film formation process based on the result of SEM analysis. In addition, with the increase of SAC-100 content, the gel content of the polymer increased significantly, while molecular weight between cross-link points (M_c) and the sol molecular weight (M_w, M_n) of the polymer decreased remarkably. The TGA result showed that the addition of the external cross-linker can enhance the thermal stability of the latex film. Moreover, for the cross-linked adhesive film, the shear strength was improved greatly while at the sacrifice of loop tack and peel strength, when compared with the uncross-linked counterparts. Besides, dynamic mechanical analysis (DMA) was also used to evaluate the viscoelastic properties of the acrylate emulsion PSA film.     

高固含量丙烯酸酯乳液压敏胶制备及性能

以丙烯酸丁酯（BA）、甲基丙烯酸甲酯（MMA）、丙烯酸（AA）、丙烯酸羟乙酯（HEA）为共聚单体，以烯丙氧基脂肪醇聚氧乙烯醚硫酸铵(SR-10)和烷基聚氧乙烯醚琥珀酸单酯磺酸二钠（A-102）作为环保型复合乳化剂，通过无种子半连续乳液聚合工艺制备了固含量高达62%的丙烯酸酯乳液压敏胶。考察了硬单体MMA用量对乳液压敏胶性能的影响。结果表明：当MMA用量为10%（以单体总质量计，下同）时，高固含量丙烯酸酯乳液压敏胶玻璃化转变温度（Tg）为-32.6 ℃，初始热分解温度为337 ℃，水接触角为108°，环形初黏为9.53 N/25mm，180°剥离强度为10.08 N/25mm，持黏力超过72 h；与未添加MMA的高固含量乳液相比，添加10% MMA后乳液黏度从361 mPa·s降至155 mPa·s，粒径从375 nm降至350 nm，粒径分布指数从0.144增至0.214。