含氟丙烯酸酯共聚物细乳液的制备及表征

采用细乳液聚合法,制备了稳定的含氟丙烯酸酯(FA)、甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)的三元共聚细乳液.用FT-IR表征了聚合物的结构组成;考查了细乳液的稳定性、乳胶膜的吸水性及耐溶剂性;用接触角法表征了乳胶膜的表面自由能.     

含氟丙烯酸酯共聚乳液的制备及表征

以甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）等为主要单体,丙烯酸全氟烷基酯（Zonyl TM）为含氟单体,甲基丙烯酸羟乙酯（HEMA）为交联单体,采用种子乳液聚合法制备了含氟丙烯酸酯共聚物乳液。研究了Zonyl TM、HEMA、引发齐（APS）用量、复合乳化剂（SDS/OP—10）、聚合温度、聚合时间和搅拌速度等因素对聚合反应最终转化率、耐水性和乳液稳定性的影响。制备的乳液单体总转化率高,乳液凝聚率低,聚合反应稳定,涂膜的综合性能优良。此外,含氟乳胶膜对水的接触角及TG分析结果表明,Zonyl TM有效参与了共聚反应,提高了涂膜的耐水性及耐热性。     

浅谈含氟丙烯酸酯共聚乳液研究进展

介绍了含氟丙烯酸酯的性能和用途,对含氟丙烯酸酯共聚乳液常规乳液聚合以及最新共聚方法进行了简单的介绍,总结出几种改进含氟丙烯酸酯体系表面性能的方法,并展望氟丙烯酸酯发展。     

聚含氟丙烯酸酯/聚氨酯共聚物细乳液的制备及表征

以甲苯二异氰酸酯(TDI)和甲基丙烯酸羟乙酯(HEMA)为原料,合成了丙烯酸酯/聚氨酯(PUA)预聚体;采用细乳液聚合法,合成了聚含氟PUA细乳液。使用红外光谱(FT-IR)和核磁共振(1H-NMR)表征了PUA预聚体及共聚物的结构组成,用激光光散射粒度仪(PCS)分析了乳胶粒的粒径及其分布,并考察了氟单体用量对乳胶膜的吸水率和表面性能的影响。研究结果表明,乳胶粒的粒径随着PUA预聚体用量的增加而增大;当氟单体质量分数由0增至20%时,乳胶膜的吸水率由10.3%降至4.2%,表面自由能由34.89mJ/m2降至15.66mJ/m2,说明氟单体的加入较好地改善了乳胶膜的表面性能。     

含氟丙烯酸酯四元共聚核壳乳液的合成与表征

采用半连续种子乳液聚合的方式,以十二烷基硫酸钠(SDS)和OP-10为复合乳化剂,甲基丙烯酸十二氟庚酯(Acty-flon-Go4)、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为原料制备了壳层含氟的核壳型丙烯酸酯共聚物乳液。研究了引发体系和聚合温度对聚合反应转化率的影响;通过透射电镜(TEM)、FTIR、示差扫描量热(DSC)对共聚物乳胶粒径、形态及结构进行了研究。     

SiO_2改性含氟丙烯酸酯乳液性能研究与表征

以甲基丙烯酸甲酯(MMA)、甲基丙烯酸–β–羟丙酯(β–HPMA)和丙烯酸六氟丁酯(F6BA)为单体,采用乳液聚合法制备P(MMA/β–HPMA/F6BA)乳液,并通过正硅酸四乙酯(TEOS)在碱性条件下水解得到的SiO2对乳液进行共混改性。研究了复合乳化剂用量、引发剂用量对乳液稳定性的影响。FT–IR分析表明,得到了目标产物;DSC分析表明,随TEOS用量的增加,共聚物玻璃化转变温度增大;激光粒度(LPS)分析表明,加入少量的TEOS使乳胶粒子的粒径显著增大,聚合物的粒径呈正态分布。     

含氟丙烯酸酯共聚乳液的合成与性能研究

由甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和丙烯酸六氟丁酯合成了含氟三元共聚乳液.采用正交方法设计实验条件,并对实验结果以及乳液成膜性能进行探讨.FTIR、1H-NMR对共聚物的组成进行了定量分析,计算得出了共聚物中各组分的摩尔百分数.对三元含氟共聚物乳液涂膜的表面性能进行测量表明,共聚物氟含量直接影响着膜的表面性能.     

聚氨酯-含氟丙烯酸酯复合乳液的制备及其表面性能

为了得到低表面自由能的聚氨酯-丙烯酸酯乳胶膜,以2,2,3,4,4,4-六氟丁醇甲基丙烯酸酯(FA)、苯乙烯(St)、丙烯酸丁酯(BA)为单体,在交联聚氨酯溶液(PU)中通过溶液聚合相转化法制得阳离子含氟聚氨酯-丙烯酸酯复合乳液(FPUA).通过FT-IR、TEM、粒径分析及接触角测试对聚合物结构、乳胶粒径及形态、乳胶膜表面性能进行了研究.研究表明,含氟丙烯酸酯的引入使聚氨酯-丙烯酸酯乳胶膜的表面自由能降低50%以上,常温固化的FPUA乳胶膜的表面自由能小于0.0172 J•m^-2;该复合乳液的粒子形态呈球形,粒径约为220 nm.     

阳离子型含氟丙烯酸酯共聚乳液的微波辐射制备

在微波辐射下,以十八烷基三甲基氯化铵为乳化剂,2,2-偶氮2甲基丙基脒-二盐酸盐（AIBA）为引发剂,将丙烯酸丁酯（BA）、甲基丙烯酸甲酯（MMA）、甲基丙烯酸十二氟庚酯（GO-4）以及甲基丙烯酰氧乙基三甲基氯化铵（DMC）进行乳液聚合,成功制备了Zeta电位在315mV左右、粒径为55~75nm的阳离子型含氟丙烯酸酯乳液。通过测定乳胶膜中氟元素含量,发现微波辐射能提高含氟单体共聚效率,使乳胶膜中氟元素含量增加。用固含量1％的阳离子型含氟丙烯酸酯共聚物乳液处理棉布织物,结果发现,棉布对水和正十六烷的接触角可分别达到111．3°、60．6°,表面自由能降至1581mJ／m2,棉布的静态吸水时间可以超过4h。     

含氟丙烯酸酯四元共聚乳液的制备

以甲基丙烯酸六氟丁酯、丙烯酸六氟丁酯、甲基丙烯酸甲酯、丙烯酸丁酯为原料采用半连续滴加工艺制备共聚物乳液。确定了最佳反应条件，并对乳化剂用量和含氟单体的用量对乳液聚合及其产品的影响进行了研究。     

Synthesis of high-molecular weight poly(vinyl alcohol) by low-temperature emulsifier-free emulsion polymerization of vinyl acetate and saponification

High-molecular weight (HMW) poly(vinyl alcohol) (PVA) was prepared via an emulsifier-free emulsion polymerization of vinyl acetate (VAc) using a redox initiation system in low temperatures, and the subsequent saponification with potassium hydroxide in methanol. The effect of the polymerization conditions on the conversion, molecular weight, and branching degree was investigated. PVA with maximum viscosity-average degree of polymerization (DP) of 8270 could be prepared by saponification of poly(vinyl acetate) (PVAc), with DP of 10,660 obtained at temperature of 10°C, monomer concentration of 30%, potassium persulfate molar ratio to monomer of 1/2000, agitation speed of 160 rpm. The conversion was above 90%. From the emulsifier-free emulsion polymerization of VAc in low temperature, PVAc with HMW and high linearity was effectively prepared, which might be useful for the preparation of high-strength and high-modulus PVA fiber. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation and characterization of ultra‐low molecular weight poly(vinyl alcohol) graft copolymer

Graft reaction of acrylamide (AM) and 4‐vinyl pyridine (4‐VP) onto ultra‐low molecular weight poly(vinyl alcohol) by ceric (IV) ion initiation had been systematically investigated; and the graft conditions were optimized by studying the effect of monomer/initiator concentration, solvents composition, reaction time and temperature. At optimized conditions, the maximum grafting efficiency and grafting ratio was ～ 50% and 51%, respectively with the presence of AM, whereas they decreased to 19% and 23%, respectively, without the presence of AM. Thermogravimetric analysis showed that as‐resulted graft copolymer had a lower thermal stability than homopolymer PVA. FTIR and ¹H‐NMR confirmed chemical structure of as‐synthesized graft copolymer. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation of antibacterial poly(sulfobetaine methacrylate) grafted on poly(vinyl alcohol)-formaldehyde sponges and their properties

Conventional wound dressings cover wound surfaces and separate them from the outer environment. However, wound sites are readily infected by some bacteria during healing. To overcome these problems, a macroporous sample is designed through the grafting polymerization of hydrophilic sulfobetaine methacrylate (SBMA) on poly(vinyl alcohol)-formaldehyde (PVF) sponges. The as-prepared PVF sponges have a grafting percentage of 15–50%, an average pore size of 60–90 μm, and a high porosity of 90%. This series of PVF-g-PSBMA sponges can absorb deionized water and saline solution at approximately 16 g·g⁻¹ within 2 min because of their hydrophilic surface and macroporous structure. The antibacterial potential of PVF-g-PSBMA sponges against Escherichia coli and Staphylococcus aureus is evaluated via a shake flask test. As the grafting percentage increase from 15 to 50%, the antibacterial activities against Gram-positive S. aureus and Gram-negative E. coli gradually increase from 87 to 95% and from 94 to 99%, respectively. The biocompatibility of these sponges is confirmed through an in vitro cell viability assay. All of the survival rates of the bacterial cells relative to the control (100% of metabolic activity) exceed 90% as the extract ratio of PVF-g-PSBMA sponges increase. Thus, the as-prepared PVF-g-PSBMA sponges can be an ideal wound dressing candidate. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47047.     

Miscibility and interactions in poly(methylthiomethyl methacrylate)/poly(vinyl alcohol) blends

Poly(methylthiomethyl methacrylate) (PMTMA) is miscible with poly(vinyl alcohol) (PVA) over the whole composition range as shown by the existence of a single glass transition temperature in each blend. The interaction between PMTMA and PVA was examined by Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy. The interactions mainly involve the hydroxyl groups of PVA and the thioether sulfur atoms of PMTMA, and the involvement of the carbonyl groups of PMTMA in interactions is not significant. The measurements of proton spin-lattice relaxation time reveal that PMTMA and PVA do not mix intimately on a scale of 1-3 nm, but are miscible on a scale of 20-30 nm. In comparison, we have previously found that PMTMA is miscible with poly(p-vinylphenol) and the two polymers mix intimately on a scale of 1-3 nm.     

粒径可控的聚丙烯酸丁酯/聚甲基丙烯酸甲酯核壳乳液的制备及表征

采用种子乳液聚合法制备了聚丙烯酸丁酯(PBA)乳液,然后通过第二单体甲基丙烯酸甲酯的预溶胀法聚合制备了PBA/聚甲基丙烯酸甲酯(PMMA)乳液,用激光散射粒度仪和透射电子显微镜对乳液粒径和结构进行了表征.结果表明,当乳化剂十二烷基硫酸钠质量分数为丙烯酸丁酯的1.5%时,可制备粒径为53.6 nm且分布窄的PBA种子乳液;通过调整补加乳化剂、单体与种子乳液的用量,可制得粒径为53.6～443.8 nm的一系列单分散PBA乳液;PBA/PMMA乳液具有完善的核壳结构,且在核壳两相间存在着一个过渡层.     

Preparation and characterizaton of poly(dimethyl amino ethyl methacrylate) modified poly(vinyl alcohol) membrane by UV radiation for the permeation of 5‐fluorouracil

Poly(vinyl alcohol) was modified by UV radiation with dimethyl amino ethyl methacrylate (DMAEMA) monomer to get poly(dimethyl amino ethyl methacrylate) modified poly(vinyl alcohol) (PVADMAEMA) membrane. The PVADMAEMA membranes were characterized by Fourier transform infrared spectroscopy. The tensile strength and elongation of PVADMAEMA membranes were measured by Universal Testing Machine. The results of X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) showed that (1) the crystalline area in PVADMAEMA decreased with increasing the content of poly(dimethyl amino ethyl methacrylate) in the membrane. (2) Only one glass transition temperature (T_g) was found for the various PVADMAEMA membranes. It means that poly(dimethyl amino ethyl methacrylate) and PVA are compatible in PVADMAEMA membrane. (3)The T_g of the membrane is reduced with increasing the content of poly(dimethyl amino ethyl methacrylate) in the membrane. The water content on the PVADMAEMA membranes was determined. It was found that the water content on the PVADMAEMA membrane increased with increasing the content of poly(dimethyl amino ethyl methacrylate). The changes of properties enhanced the permeability of 5‐Fluorouracil (5‐Fu) through the PVADMAEMA membranes. A linear relationship between the permeability and the weight percent of poly(dimethyl amino ethyl methacrylate) in the PVADMAEMA membrane is found. It is expressed as P (cm/s) = (9.6 ± 0.4) × 10^?5 + (8.8 ± 0.6) × 10^?5 W _x , where P is the permeability of 5‐Fu through the membrane and W_x is the weight percent of poly(dimethyl amino ethyl methacrylate) in the PVADMAEMA membrane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Influences of individual and composed poly(vinyl alcohol) suspending agents on particle morphology of suspension poly(vinyl chloride) resin

Effects of individual and composed poly(vinyl alcohol) (PVA) suspending agents on the particle morphology of poly(vinyl chloride) (PVC) resins were investigated and discussed in the view of PVA absorption at the oil/water interface and interfacial behavior. It was shown that the percentage and surface coverage of PVA at the oil/water interface decreased with the increase of the degree of hydrolysis (DH) of PVA in the DH range of 70–98 mol %, while the interfacial tension of VC/PVA aqueous solution increased linearly with the increase of DH of PVA. PVC resin with more regular particle shape, increased agglomeration and fusion of primary particles, lower porosity and higher bulk density, was prepared by using PVA with a higher DH as a suspending agent. This was caused by the occurrence of drop coalescence at the very early stage of VC polymerization, the increase of particle shrinkage, and the lower colloidal protection to primary particles. It was also shown that the interfacial tension of VC/water in the presence of composed PVA suspending agents varied linearly with the weight composition of the composed PVA suspending agents. The particle properties of PVC resin prepared by using the composed PVC suspending agents were usually situated in between the properties of PVC resins prepared by using the corresponding individual PVA suspending agent. The particle morphology and properties of PVC resin could be controlled by the suitable choice of the composed PVA suspending agents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3848–3855, 2003     

Preparation and characterization of poly(vinyl alcohol)‐poly(vinyl pyrrolidone) blend: A biomaterial with latent medical applications

Aqueous solutions of poly(vinyl alcohol) and poly(vinyl pyrrolidone) are blended and films are produced by casting method with the further intention of being used as bio‐materials with latent medical application. Glutaraldehyde, 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt tetra‐hydrate are used as crosslinker agents, whereas lactic acid is the plasticizer in the blend. The obtained films are characterized by differential scanning calorimetry (DSC), mechanical properties, swelling and solubility behavior. DSC measurements show that the blends exhibit a single glass transition temperature indicating that they are miscible, even in the presence of the plasticizer and crosslinker agents. By the combination of all mentioned additives, a relevant enhancement of the swelling is observed, accompanied by a stabilization of the solubility during the tested time. Finally, mechanical properties show an appropriate performance in the studied parameters. As a consequence, the obtained films could be suitable for use as medium or long‐term implants. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation and characterization of a bioadhesive with poly (vinyl alcohol) crosslinking agent

Synthetic adhesives containing 3,4‐dihydroxy‐L‐phenylalanine and its derivatives have strong adhesion strength and good biocompatibility, which make them prime candidates for adhesives or bioadhesives applications. In this study, a new photocurable poly (vinyl alcohol) (UV‐PVA) derivative was prepared and used as crosslinking agent to further improve adhesion strength of dopamine methacrylamide (DMA) system. The structure of UV‐PVA was confirmed, and the degree of acryloyl group substitution (DS) was easily varied from 10 to 40% by varying the molar ratio of acryloyl chloride to ? OH of PVA. The effects of ultraviolet light intensity, content of DMA and DS values of PVA on the photopolymerization kinetics were studied, and the effects of DS value on the adhesive strength, swelling performance and cell attachment were also investigated. It was found that adhesive containing UV‐PVA with 40% DS value yielded the highest adhesive strength, a relatively low swelling ratio and good biocompatibility. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013