Soft Monomer Research Articles

Abstract 168: YAP and TAZ Mediate Mechanical Control of Vasculogenesis

Physical cues such as the mechanical properties of the extracellular matrix are known to modulate blood vessel formation, but the underlying mechanisms remain poorly understood. Yes-associated protein (YAP) and transcriptional activator with PDZ-binding domain (TAZ) were recently identified as key mediators of cellular mechanotransduction [1], but the roles of YAP and TAZ in neovascular mechanobiology have not been investigated. We hypothesized that YAP and TAZ mediate neovascular mechanotransduction of extracellular matrix rigidity by vasculogenic endothelial colony forming cells (ECFCs) cultured on/in matrices of controllable rigidity. YAP and TAZ depletion abrogated ECFC migration (Fig. 1A), and YAP/TAZ expression and nuclear localization (i.e., activation) was significantly upregulated in migrating cells (Fig. 1B). Combinatorial depletion also abrogated tubular network formation and 3D vasculogenesis in collagen matrices of variable rigidity but constant matrix density (data not shown). In 2D, PDMS rigidity regulated YAP/TAZ subcellular localization (data not shown). In 3D, vasculogenesis was enhanced in stiff (G’= 1049 Pa) collagen oligomer matrices compared to soft (G’ = 305 Pa) monomer matrices formulated at constant collagen matrix density. YAP and TAZ were nuclear localized (activated) in the stiff oligomer matrices, but cytosolic in soft monomer matrices (Fig. 1C). Mechanistically, YAP and TAZ depletion reduced cytoskeletal stress fiber formation (data not shown), implicating YAP and TAZ in a feedback mechanism to control cytoskeletal remodeling. Delivered in oligomer matrices in vivo , ECFCs formed a functional human neovascular plexus and exhibited strong expression and nuclear localization of YAP and TAZ and expression of downstream genes, Cyr61 and CTGF (data not shown). In summary, YAP and TAZ are essential for mechanical control of ECFC migration and vasculogenesis. [1] Dupont et al. 2011 Nature. 474:179-185.

Polyethylene-supported poly(methyl methacrylate-co-butyl acrylate)-based novel gel polymer electrolyte for lithium ion battery

A new copolymer, poly(methyl methacrylate-co-butyl acrylate) (P(MMA-co-BA)), was synthesized by emulsion polymerization with different mass ratio of methyl methacrylate (MMA) and butyl acrylate (BA). The membranes were prepared by phase inversion and corresponding gel polymer electrolytes (GPEs) were obtained by immersing the membrane into a liquid electrolyte. In this design, the hard monomer MMA provided the copolymer with good electrolyte uptake, while the soft monomer BA provided the GPE with strong adhesion between the anode and cathode of lithium ion battery. The properties of the resulting product were investigated by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectra, scanning electron spectroscopy, linear sweep voltammetry, thermogravimetric analysis, cyclic voltammetry, electrochemical impedance spectroscopy and charge/discharge test. The results show that the obtained GPE based on P(MMA-co-BA) with the mass ratios of MMA and BA = 6:1 exhibits good conductivity (as high as 1.2 × 10−3 S cm−1) at room temperature and high electrochemical stability (up to 4.9 V vs. Li/Li+). With the application of the polyethylene (PE)-supported GPE in Li/Li(Li0.13Ni0.30Mn0.57)O2 battery, the battery presents good cyclic stability (maintaining 95.4 % of its initial discharge capacity after 50 cycles) at room temperature.

Siloxane‐modified polyacrylate low‐residual pressure‐sensitive adhesive with high peeling strength

ABSTRACTA low‐residual siloxane‐modified polyacrylate pressure‐sensitive adhesive (PSA) with a high peeling strength was prepared by seeded semicontinuous emulsion polymerization. 3‐Glycidyloxypropyltrimethoxysilane was introduced into the acrylic (AC) PSA through a thermal posttreatment method to crosslink with AC. To improve the adhesion properties, a polymeric emulsifier, 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid, was introduced into the system with the conventional emulsifier. Several key polymerization conditions, such as the initiator concentration, mass ratio of soft monomer to hard monomer, the content of polymeric emulsifier, and siloxane dosages were examined in detail. Then, the optimal conditions and a proper preparation process were established. The results show that we achieved not only a low repeeling residue with high tack and peeling strength but also excellent properties of high‐temperature aging resistance and water resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42975.

Nonionic surfactant-stabilized raspberry-like polymer/silica nanoparticles latex with film formability

Raspberry-like P(St-BA)/SiO2 nanoparticle latexes were prepared via miniemulsion polymerization of styrene (St) and butyl acrylate (BA) in the presence of 20 nm glycerol-modified SiO2 sol as a Pickering emulsifier and octaphenyl polyoxyethylene (CA-897) as a nonionic surfactant, using 2,2-azobis (isobutyronitrile) (AIBN) as an initiator. 2-(Methacryloyl) ethyltrimethylammonium chloride (MTC) was introduced to act as an auxiliary monomer to enhance the attraction of SiO2 sol onto latex nanoparticles (NPs) via increasing their electrostatic interaction with negative-charged SiO2 sol. The average particle sizes of the latex particles can be well controlled from 200 to 360 nm by variation of the SiO2 sol content as well as soft monomer BA component. The latex NPs displayed a good colloidal stability with excellent resistance to both strong acidic and basic environment. Furthermore, the nanosized latexes exhibited good film formability. The influence of reaction parameters, e.g., the initial silica amount and soft monomer BA content was systematically investigated on the film performances, such as hardness, abrasive resistance, water absorption, gloss. The results indicated that the increase of SiO2 sol content can contribute to the increase of the film hardness and water absorption ability, while increasing BA component is beneficial to the improvement of the film gloss.

Preparation and characterization of poly(vinylidene fluoride) flat sheet membrane with Tg tunable amphiphilic terpolymer as membrane additive

An amphiphilic terpolymer P(MMA-BA-PEOM) was synthesized by free radical polymerization and used as the macromolecular additive in the preparation of PVDF blend membranes. The glass transition temperature (Tg) of terpolymers was controlled with a wide range from −6 to 40°C by adjusting the feed ratio of rigid monomer MMA to soft monomer BA. The increase of static contact angle of copolymer with PBA content indicated that softer chain can facilitate the hydrophobic parts of the additive segregation to the surface of a polymer film at the solid–air interface. The observation of morphology of the extracted PVDF blend membrane verified that P(MMA-BA-PEOM) could facilitate the surface segregation. Filtration experiment showed that PVDF membrane modified by terpolymer P(MMA-BA-PEOM) has a higher pure water flux (365Lm−2h−1) and relative flux recovery (71%) than that modified by bipolymer P(MMA-co-POEM).

Study on Tough Blends of Polylactide and Acrylic Impact Modifier

Acrylic impact modifiers (ACRs) with different soft/hard monomer ratios (mass ratios) were prepared by semi-continuous seed emulsion copolymerization using the soft monomer butyl acrylate and the hard monomer methyl methacrylate, which were used to toughen polylactide (PLA). The effect of soft/hard ACR monomer ratio on the mechanical properties of PLA/ACR blends was investigated. The results showed that the impact strength and the elongation at break of PLA/ACR blends increased with increasing soft/hard ACR monomer ratio, while the tensile and flexural strengths of PLA had little change. The impact strength of PLA/ACR blends could be increased about 4 times more than that of pure PLA when the soft/hard monomer ratio of ACR was 90/10, which was the optimal ratio for good mechanical properties of PLA. Additionally, the possible mechanism of ACR toughening in PLA was discussed through impact fracture phase morphology analysis.

Emulsion Semi-Batch Terpolymerization Process Using Hybrid Emulsifiers for Synthesizing New Emulsion Pressure Sensitive Adhesives (EPSAs)

In order to obtain a suitable formulation of designing direct synthesis of acrylic latexes to be used as emulsion pressure sensitive adhesives (EPSA), having high shear resistance together with high peel strength and tack, free radical emulsion polymerization of hard monomers, such as styrene (St), vinyl acetate monomer (VAM), methyl methacrylate (MMA) and butyl methacrylate (BMA), and soft monomers, butyl acrylate (BA) and 2-ethylhexyl acrylate (2-EHA) along with multifunctional monomers, namely acrylic acid (AA), were carried out. The effect of the type of hard and soft acrylic monomers, the type and level of emulsifiers, and the initiator concentration on the emulsion polymer stability and final properties of the EPSA were investigated. The results obtained showed an optimized composition. This composition led to a significant increase in shear strength and peel strength to 909 kPa and 0.45 N/mm, respectively, while the synthesized PSA was still too tacky, 5.5 cm, according to adhesion performance testing. For making this successful balance of the conflicting adhesion properties of PSA, a series of anionic and nonionic emulsifiers were investigated. It was interestingly found out that the hybrid emulsifiers (anionic coupling with nonionic) with the optimized compositions could enhance the stability of the emulsion system and improve the properties of PSA compared with the mono-emulsifier. We also tried to adjust the initiator concentration with the level of the optimized hybrid emulsifier, polyoxyethylene alkyl phenyl ether (K30), dioctyl sulfosuccinate (DOSS), and sodium vinyl sulfonate (SVS) with the ratio 2:1:1, resulting in a highly preferred proportion of the 0.5 part of the initiator versus 1.25 parts of the hybrid emulsifier in terms of the total weight of the monomers.

Effect of Polymeric Emulsifier and Ratio of Soft/Hard Monomer on the Property of Acrylic Emulsion as Fabric Stiffening Agent

By adding polymeric emulsifier, acrylic emulsion as the fabric stiffening agent with core-shell structure was synthesized visa monomer concentration gradient dropwise addition method. The effect of synthetic condition such as the content of polymeric emulsifier and ratio of soft monomer (BA)/hard monomer (MMA) on properties of acrylic emulsion were studied in detail, and the role of polymeric emulsifier during the process of the film-forming was also discussed. Films after tackiness resistance, minimum filming temperature (MFT) and glass transition temperature (Tg) were tested by QNF, QMB type measuring instrument and differential scanning calorimeters (DSC), respectively. Transmission electron microscopy (TEM) observed the morphology of latex particles. Results showed 40wt% polymeric emulsifier was the best emulsifying system in term of emulsion stability, after tackiness resistance, MFT and appearance of the emulsion. DSC analysis confirmed that the polymeric emulsifier and acrylic emulsion could not fully achieve thermodynamic compatibility. In addition, TEM results showed that latex particles prepared by monomer concentration gradient dropwise addition method had obvious core-shell structure. Hydrogen-bond interaction between polymeric emulsifiers carboxyls played a great role in the film-forming process, so polymeric emulsifier could improve films after tackiness resistance and MFT.

Preparation and Characterization of Novel Naturally Renewable Resin Acid Based Monomer

Rosin, an abundant renewable natural resin obtained from exudation of pine trees, has attracted a great deal of attention because of its utilization as a feedstock for the preparation of polymers in the age of the depletion of fossil fuels. Dehydroabietic acid (DA) is one of important resin acid that could be produced with large scale and high purity. In this paper, we reported a new synthetic strategy to prepare a novel resin acid based monomer with acrylic group (DAHA) by sequential reaction of DA with 1,6-hexanediol and acryloyl chloride. The structure and properties of DAHA and DA monoester of 1,6-hexanediol (DAH), an intermediate compound, were characterized by FT-IR, 1H NMR, 13C NMR, MS, DSC and GPC. The results showed that DAHA has high purity and could undergo free radical polymerization. DAHA is a soft monomer with the glass transition temperature of-23.52 °C and can impart flexibility to the polymer integrated. This study illustrates a new synthetic strategy to prepare a new class of resin acid based monomer.

Study on Preparation and Property of Acrylic Resins Used for Water-Based Ink

In this paper, a kind of water-soluble acrylic emulsion with methyl methacrylate (MMA) and butyl acrylate (BA) as hard and soft monomer respectively, acrylic acid (AA) and hydroxypropyl methacrylate as functional monomers, ammonium persulfate (APS) and ammonia as initiator and neutralizer respectively, was prepared by emulsion polymerization. The resulting emulsion possesses high solid content, low viscosity, high stability and film-forming properties, indicating that it would be applicable to water-based ink. The effect of the ratio of MMA to BA on the film-forming properties of resin and the influence of AA and HPA on the water-soluble property and viscosity of resin were investigated, and the relationship of reaction temperature and the emulsion stability was also studied. This paper can provides a certain reference to synthesis of acrylic resin and application of acrylic resin to the water-based ink.

Preparation and Sizing Performance of the Modified Collagen Surface Sizing Agent

Using collagen as the raw material, methyl acrylate and vinyl acetate as the soft and hard monomers, ammonium persulfate as the initiator, a surface sizing agent was prepared by the emulsion polymerization method to modified the collagen. The optimum prepared conditions were got by the single factor experiment, follow as m(soft monomer)/m(hard monomer) for 1:2 or 1:1, m(collagen)/m(monomer) for 1:2, the dosage of initiator for 0.8% of monomers amount, the reaction time for 2h. The FT-IR showed that the grafting reaction between vinyl monomers and collagen happened and the vinyl monomers reacted completely. The particle size distribution of the emulsion indicated that its size distribution was uniform and the average size was 0.117μm. The results of application experiments showed that the tensile strength and tearing strength of paper were stronger than that of base paper for 3 times and 1.9 times, after sizing by using the emulsion. The water-resistance of paper was also improved.

Synthesis of ambient temperature self-crosslinking VTES-based core–shell polyacrylate emulsion via modified micro-emulsion polymerization process

Modified micro-emulsion polymerization was successfully used to synthesize a kind of ambient temperature self-crosslinking core–shell emulsion, consisting of polyacrylate core and vinyltriethoxysilane (VTES) modified polyacrylate shell, by varying the ratio of soft monomer (BA) and hard monomer (MMA) which is different in the core and shell. The emulsion and its film formed at ambient temperature were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Core–shell structure was clearly shown in TEM micrographs, and two distinct glass transition temperatures (Tg) were confirmed by DSC analysis. Lower Tg of core phase analyzed by DSC and self-crosslinking properties of VTES characterized by crosslinking degree cause latex particles form continuous film at ambient temperature. Thermal and mechanical properties and the surface properties of the latex films were also investigated. Results showed that the core–shell latex films containing 5 and 7.5 % VTES exhibited higher thermal stability, better mechanical properties, higher contact angle, and water resistance compared with pure polyacrylate film.

Synthesis and characterization of organic-inorganic hybrid block copolymers containing a fully condensed ladder-like polyphenylsilsesquioxane

A series of inorganic–organic hybrid block copolymers were synthesized via atom transfer radical polymerization using a fully condensed, ladder-like structured polyphenylsilsesquioxane end-functionalized macroinitiator. The inorganic portion, ladder-like polyphenylsilsesquioxane, was synthesized in a one-batch, base-catalyzed system, whereas organic hard and soft monomers, styrene, and n-butyl acrylate, were polymerized and copolymerized on the ends of the linear, inorganic backbone. Synthesized hybrid diblock, triblock, and random copolymers were characterized by 1H NMR, 29Si NMR, gel permeation chromatography, static light scattering, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Hybrid block copolymers were well-defined with low polydispersity (<1.4) and exhibited enhanced thermal properties in the form of increased glass transition and degradation onset temperatures over their organic analogues.© 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Study on Emulsion Polymerization of Fluorinated Acrylate and its Application

Using fluorinated acrylate (FDA) as functional monomer,the co-polymeric emulsion were prepared with acrylates(homemade) as soft monomers,sodium dodecyl sulfate (SDS) and Span-80 as emulsifie,ammonium persulfate as initiator,and methyl methacrylate(MMA) as stiff monomer.The obtained latex was characterized by FT-IR,and was used to treat cotton fabrics. Adopting two dipping and two padding finishing processes, then the treated fibrics were dried at 110°C for 1.5 min,finally cured at 170°C for 3min.The contact angles, water/oil repellency and mechanical properties of treated fabrics were tested. The results showed that the contact angle can approach to 134.3 °, water-repellency rate and oil-repellency rate of the treated fabrics can reach grade 3-4 and 1, respectively. There was little change in whiteness and wrinkle recovery angle.

Research on Preparation of Transparent Hydrophilic Antifogging Acrylate Resin

Solution polymerization method was used to prepare hydrophilic antifogging acrylate resin. By means of comparison, the optimum synthesis technology conditions was obtained that ethyl acrylate was used as soft monomer , methylcrylate was used as hard monomer. The best functional monomers was acrylic acid and methyl acrylic acid. The accessory functional monoer was β-hydroxyl ethyl acrylate. Cross-linking agent methylol acrylamide belongs to self-cross-linking system. Crosslinker was N-hydroxymethyl acrylamide.The quality rate of cross-linking agent and carboxylic acid is 4 to 1 .The resin can be cured perfectly at the temperature of 100°C in 40 min. The prepared acrylate resin had excellent water-solubility and antifogging.

Influences of Soft Monomers on the Application Properties of Hydrophilic Polyurethane with Mixed Polyether Segment

A series of hydrophilic polyether polyurethanes were prepared with two-steps technique from 4,4’- diphenylmethane diisocyanate (MDI), polytetramethylene glycol 1000 (PTMG1000) and polyethylene glycol 1000 (PEG1000) with 1,4-butanediol (BDO) as the chain extender. Further more, the relationships between structure and moisture permeability, water resistance, hydrophility and phase inversion temperature (PIT) of the polyurethanes was investigated. For polyether polyurethanes with nicer micro phase separation structure, the studies show that the hydrophilic ether bond content and mobility of soft segment chains have decisive effect on their water resistance, moisture permeability and hydrophility without reference to the soft segment content on the whole.

Research on Preparation of Cationic Polyacrylate Emulsion Paper Strengthening Agent

Strengthening agent of cationic polyacrylate emulsion was prepared through semi-continuous seeded pre-emulsion processes. By single factor experiment, investigated the factors which influence on properties of emulsion, such as the proportion of hard and soft segment monomer, the dosage of AM, DMDMAC, emulsifier and initiator, reaction time and temperature, addition time and other factors. The results show that the emulsion has a good enhancement when the monomer ratio of St: MMA: BA is 2:1:3, initiator dosage is 0.7%, the dosage of emulsifiers, AM and DMDMAC are 6%, the amount of protective colloid is 0.3%. Compared to the strength performance between paper with added emulsion and blank paper, find that the performance of paper with added emulsion polymer gets different improves: paper quantitative increase 4.08%, folding strength degree improves 66.67%, tearing degree improves 356.52%, ring compressive strength improves 50.00%, tensile strength improves 44.11%, and bursting strength improves 50.88%

Study on the Influences of Domain Structure of Hydrophilic Polyurethane with Partially Crystalline on its Moisture Permeability

Multiphase, segmented polyurethanes with mixed soft segment phase were prepared from 4,4’- diphenylmethane diisocyanate (Pure MDI), polybutylene adipate (glycol) 2000 (PBA2000) and polyethylene glycol 1000 (PEG1000) with 1,4-butanediol (BDO) as the chain extender. Further more, the relationships between domain separation structure, crystallizability of soft segment and moisture permeability, hydrophilic property, phase inversion temperature (PIT) of the polyurethanes were investigated. The studies show that the chemical structure, concentration of hydrophilic soft monomers and the microphase separation degree of the mixed soft segments from hard segment domain have remarkable effects on the application properties of polyurethane.

Analysis and Synthesis of Surface Sizing Agent BLD-02

The chemical composition of surface sizing agent BLD-02 was researched, as well as its synthesis method. BLD-02 was analyzed by infrared spectroscopy, and the main monomers were styrene, acrylate and acrylonitrile. In the process of synthesis, these monomers were prepared for copolymer latex by seed emulsion polymerization. Through a series of pre-trial, the results showed that when the contents of initiator and emulsifying agent were 0.3% and 3% (the percentage of total) respectively, the weight ratio of hard monomer to soft monomer was 2/3 and the reaction temperature was 75°C, the synthetic emulsion with higher viscosity, smaller particle size and well-dispersion was prepared. Results showed that the infrared spectrum and properties of the synthetic emulsion, to some extent, were as same as that of BLD-02.

Effects of soft monomers on the water resistance and moisture permeability of hydrophilic polyurethane

Six groups of segmented polyurethanes with amorphous soft segment domains based on mixed hydrophobic polyester and hydrophilic polyether soft monomers were prepared from 4, 4′-diphenylmethane diisocyanate (MDI), polybutylene adipate glycol 2000 (PBA2000), polytetramethylene glycol 1000 (PTMG1000) and polyethylene glycol 1000 (PEG1000) with 1,4-butanediol (BDO) as the chain extender. Furthermore, the representative properties of the hydrophilic polyurethanes, moisture permeability and water resistance, were investigated. The results show that the chemical structure, molecular weight and concentration of soft monomers have remarkable effects on the main application properties of hydrophilic polyurethane. The important factors in diffusion are the content of hydrophilic ether bond and the mobility of hydrophilic chain in the soft phase, which is represented with a good approximation by the average mean molecular weight of soft segment. On the contrary, the functional properties of the hydrophilic polyurethane are almost not affected by its hard segment.