Polymer networks based in (4‐vinylbenzyl)‐N‐methyl‐D‐glucamine supported on microporous polypropylene layers with retention boron capacity

New cellulose porous layers, with capacity to transport and retain boron from aqueous solution, were developed via interpenetrating polymer network (IPNs). These polymer systems were made to assemble mimetic systems of plant root tissue for the study of available boron transport. For that cellulose porous layers supported on polypropylene matrix were used as primary network for the formation of IPN. A vinyl monomer, (4‐vinylbenzyl)‐N‐methyl‐d ‐glucamine (VbNMDG), was synthesized at three concentration levels and cellulose ultrafiltration membranes were modified by in situ polymerization in the inside of the pores. Change of hydrophilicity, percent of secondary network, permeability and retention properties were studied. The formation of IPNs in the inside of the pores decreased the permeabilities of polymer layers. In addition, a decrease of hydrophilicity was seen. A linear increase of boron retention in function of VbNMDG concentrations was observed for the different boron concentrations and a negative effect on retention capability was evidenced for several charge and discharge cycles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40653.     

Camelina oil‐ and linseed oil‐based polymers with bisphosphonate crosslinks

Natural oils are the attractive biobased alternatives for petroleum derived chemicals in the production of polymers. A series of new biodegradable polymers based on epoxidized camelina oil was synthesized and investigated. The thermal, mechanical, swelling properties, hydrolysis, biodegradation, and bioresistance of the camelina oil‐based polymers with bisphosphonate crosslinks were studied and compared with those of the analogous polymers based on epoxidized linseed oil. The dependence of the polymer properties on the density of crosslinks was observed. The obtained results showed that the properties of the camelina oil‐based polymers are comparable with those of the linseed oil‐based polymers and that camelina oil is a promising starting material for the synthesis of polymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40683.     

The effect of depth and duration of UV radiation on polypropylene modification via photoinitiation

Linear polypropylene (PP) was modified using UV radiation in the presence of 0.5 wt % of benzophenone photoinitiator to introduce long chain branching (LCB) to the PP backbone. Irradiation was carried out in the solid state and the temperature level was kept below 60°C. The effects of radiation duration and sample thickness on the extent of these branching modification reactions were investigated. Viscoelastic properties, molecular weight, molecular weight distribution, and gel content were determined and compared for runs having different sample thicknesses, irradiated for different times. Comparisons were also conducted with the parent PP and the PP mixed with photoinitiator. It was found that LCB decreased by increasing the thickness of the samples. Conversely, an increase in radiation duration resulted in enhanced LCB but also led to larger gel content in the samples. Based on all these measurements and observations, a mechanism was suggested to explain formation of long chain branches (LCBs) in PP in the solid state via photoinitiation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41021.     

Highly efficient antifouling property based on self‐generating hydrogel layer of polyacrylamide coatings

Pursuit of robust antifouling coatings is a persistent objective for marine materials. We present here the experimental realization of a series of polyacrylamide‐based resins with a self‐generating hydrogel layer, arising from the polymerization of acrylamide (AM), butyl acrylate, methacrylic acid, and AM derivatives. The mechanical strength and thermal stability are markedly enhanced due to the change of the structure of modified resins. The preliminary results indicate that resultant resins with crosslinking structure show satisfactory abrasion resistance and swelling properties. The results of antifouling panel testing in shallow submergence for three months reveal that the addition of AM derivatives leads to generation of a thin soft and dynamic layer of hydrogel, which enhances antifouling properties. The formation of hydrogel and self‐generating property make it promising in various antifouling applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44111.     

Preparation of polyacrylate/paraffin microcapsules and its application in prolonged release of fragrance

The purpose of the present work was to develop a fragrance encapsulation system using polyacrylate/paraffin microcapsules. The Polyacrylate/paraffin microcapsules were fabricated by the method of suspension polymerization in Pickering emulsion. Morphology, size distribution, and thermal resistance of polyacrylate/paraffin microcapsules were investigated by scanning electron microscopy, light scattering particle size analyzer, and thermogravimetric analyzer. Results indicated that the crosslinked PMMA/paraffin microcapsules and P(MMA‐co‐BMA)/paraffin microcapsules prepared under optimal conditions presented regular spherical shape and similar size distribution. The crosslinked P(MMA‐co‐BMA)/paraffin microcapsules exhibited better thermal stability, with a thermal resistance temperature up to 184 °C. Fragrance microcapsules were prepared by encapsulating fragrance into crosslinked P(MMA‐co‐BMA)/paraffin microcapsules. The prolonged release performance of fragrance microcapsules was measured by ultraviolet‐visible near‐infrared spectrophotometer. 63.9% fragrance was retained after exposing fragrance microcapsules in air for 3 months, and the fragrance continued to release over 96 h in surfactant solution (sodium lauryl sulfonate, 20 wt %). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44136.     

Hyperbranched polyglycerol/poly(acrylic acid) hydrogel for the efficient removal of methyl violet from aqueous solutions

Hydrogels were synthesized from hyperbranched polyglycerol (HPG) and acrylic acid through free‐radical polymerization with HPG as the crosslinker. The HPG/poly(acrylic acid) (PAA) hydrogel could absorb cationic dyes in aqueous solutions because of the existence of a porous structure and the large numbers of hydroxyl and carboxylic groups. With methyl violet chosen as a model compound, the HPG/PAA hydrogel reached a maximum adsorption of 394.12 mg/g at a feed concentration of 1 g/L. The highest removal ratio of 98.33% was observed at a feed concentration of 50 mg/L. The effects of the pH, contact time, and feed concentration on the dye adsorption were investigated. The dye adsorption data fit well with the pseudo‐second‐order and Langmuir models. We believe that the HPG/PAA hydrogels could perform well in appropriate applications in the removal of cationic dyes from aqueous solutions because of their high adsorption capacity and environmental friendliness. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42951.     

Chemorheological time‐temperature‐transformation‐viscosity diagram: Foamed EPDM rubber compound

Thermal analysis, rheometry, and kinetic modeling are used to generate a comprehensive processability diagram for thermosetting and elastomeric resins. A chemorheological “time‐temperature‐transformation‐viscosity” diagram is proposed to fully characterize curing reactions toward process' on‐line control, optimization, and material design. Differential scanning calorimetry and thermogravimetric techniques are used to measure total reaction heat, degree of vulcanization, and cure kinetics. The viscosity, as a function of temperature and cure degree, is obtained from parallel plate rheometry. The auto‐catalytic Kamal–Sourour model, including a diffusion‐control mechanism, is used to model cure kinetics, while the Castro–Macosko model serves to model the rheological behavior. Non‐linear least‐squares regression and numerical integration are used to find models' parameters and to construct the chemorheological diagram. The usefulness of the proposed methodology is illustrated in the context of an industrial‐like Ethylene Propylene Diene Termononer rubber compound that includes a chemical blowing agent. Even though the rubber formulation contains crosslinking agents, primary and secondary accelerators, promoters, activators, and processing aids, the chemorheological diagram is obtained consistently, validating the proposed methodology to any thermosetting or elastomeric resin. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43966.     

Slightly crosslinked polyurethane with Diels–Alder adducts from trimethylolpropane

Diels–Alder (DA) reactions between furan and maleimide have been widely applied in thermally remendable polymeric materials. Crosslinked polyurethane with DA adducts exhibited much better mechanical properties than linear polyurethane with DA adducts. However, the highly crosslinked polyurethane needs a higher temperature and a longer healing time. This will increase the possibility of side reactions proceeding during the healing procedure. In this paper, slightly crosslinked polyurethane with DA adducts was synthesized by incorporating trimethylolpropane into linear polyurethane with DA adducts. The structure of the intermediate and final products was characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, and differential scanning calorimetry, confirming that the synthesizing process proceeded successfully. The images from the polarizing optical microscope demonstrated that the final product with slight crosslinking needed less time and a lower healing temperature to complete the healing procedure. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43971.     

Impressive Rate Raise of the Hydrosilation Reaction Through UV‐Activation: Energy and Time Saving

Silicone materials are widely used in many fields such as electrical or food industries and their consumption is constantly growing. They are generally cured by vulcanization reaction for long time at high temperatures which requires high energy consumption. The possibility to achieve the polymerization of silicone rubbers by UV‐activation promotes the reduction of both time and temperature leading to an impressive energy saving. Indeed, this process is more than 30 times faster than the thermal one. Moreover, the properties of the two resulting materials are comparable, indicating that the low time of UV‐activated hydrosilation reaction is suitable for the formation of crosslinked silicone polymers.

     

POE与EPDM性能的比较

笔者主要研究了聚烯烃热塑性弹性体POE(Engage 8150)和EPDM的各种静态力学性能，比较了POE和EPDM在相同过氧化物用量、相同白炭黑用量补强的情况下两者的力学性能。结果表明，相同DCP用量的情况下，POE的交联程度不如EPDM，但力学性能不低于EPDM。在相同白炭黑用量补强时，POE除硬度略大于EPDM、耐磨性略差外，POE其余各项物理性能均高于EPDM。POE可作为EPDM的替代材料。