Composites of poly(vinylidene fluoride) (PVDF), silicone rubber (SR), and zinc dimethacrylate (ZDMA) were prepared via peroxide dynamic vulcanization. The effect of ZDMA loading on the morphology, mechanical properties, and rheology of the PVDF/SR/ZDMA composite was investigated. It was found that, some rubber particles with different diameters were aggregated and distributed in the PVDF matrix. The average diameters of rubber particles increased when ZDMA was incorporated into the PVDF/SR blend. A higher content of ZDMA seemed to show a favorable effect on the mechanical properties of PVDF/SR/ZDMA composites. The tensile strength, flexural strength, and flexural modulus of PVDF/SR/ZDMA composites decreased with increasing the ZDMA loading, which was due to the decreased tensile strength and total crosslink density of SR/ZDMA composite and the increased diameter of rubber particles, but the compatibility and interfacial interaction between PVDF phase and SR phase were obviously improved, which contributed to improved the Izod impact strength. In addition, the rheology analysis also suggested that interfacial adhesion between PVDF phase and SR phase was improved due to the incorporation of ZDMA. POLYM. COMPOS. 37:1093–1100, 2016. © 2014 Society of Plastics Engineers

Blends of poly(vinylidene fluoride) (PVDF) and silicone rubber (SR) were prepared through melt mixing. The morphology, rheology, crystallization behavior, mechanical properties, dynamic mechanical properties and thermal properties of the PVDF/SR blends were investigated. The blend with 9 wt % of SR showed spherical shape of disperse phase whereas the blend with 27 wt % of SR resulted in irregular shape of rubber phase. The rheology showed that the complex viscosity and storage modulus of the blends decreased with increasing the SR content. The mechanical properties of the blends were decreased with increasing the SR content but that were significantly improved after dynamical vulcanization. The crystallization temperature of PVDF phase in PVDF/SR blends was increased. The incorporation of SR improved the thermal stability of PVDF/SR blends, and the temperature at 10% mass loss of the blends increased to about 489°C compared with 478°C of the pure PVDF. The mass of residual char in experiment of the blends was lower than that obtained in theory. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39945.

Ethylene propylene diene monomer (EPDM) was blended with glass fibers (GFs)-filled poly(ethylene 2,6-naphthalate) (PEN) composites to improve the impact properties of PEN. The impact strength of PEN/EPDM/GF composite (PEN/EPDM = 60/40) was about 62 J/m, which was nearly four times higher than the PEN/GF composite without EPDM. At the same time, the tensile strength and flexural modulus were still maintained at considerable values since the GFs compensated the loss of mechanical properties of PEN by incorporation of EPDM. The scanning electron microscopy results showed that the GFs were orientated and homogenously dispersed in the PEN matrix and, after incorporation of EPDM, the surface of GFs were covered by a matrix layer which became coarse and thick with increasing EPDM content. The dynamic mechanical analysis results showed the poor compatibility between PEN and EPDM. The thermal gravimetric analysis revealed that the PEN matrix protected the dispersed EPDM domains, resulting in an increased maximum peak temperature (T_max) of the EPDM phase. At last, the results of differential scanning calorimetry analysis indicated that incorporation of EPDM led to an increase in crystallization rate and improvement in crystallization temperature. POLYM. COMPOS., 35:939–947, 2014. © 2013 Society of Plastics Engineers

This study demonstrated an approach of compatibilization between polypropylene (PP) and nitrile butadiene rubber (NBR) by using zinc dimethacrylate (ZDMA) as a reactive compatibilizer in the presence of peroxides. The PP/NBR/ZDMA ternary blends with improved mechanical properties were successfully prepared via peroxide dynamic vulcanization. The resultant blends exhibited a significant increase in mixing torque and complex viscosity after incorporation of ZDMA. Morphology studies showed that the addition of ZDMA reduced the size of the crosslinked NBR phase. Transmission electron microscopy (TEM) combined with scanning electron microscopy (SEM) verified that the possible reactions between ZDMA, NBR, and PP increased the interfacial thickness and improved the compatibility between NBR and PP phase. Crystallization behavior analysis indicated that incorporation of ZDMA promoted the nucleation process of PP. Thermal gravimetric analysis (TGA) showed that the maximum degradation temperature was increased by ZDMA. POLYM. ENG. SCI., 54:2321–2331, 2014. © 2013 Society of Plastics Engineers

In this work, the tensile property of natural rubber (NR) reinforced by zinc dimethacrylate (ZDMA) at various temperatures was studied. The results showed that the strain-induced crystallization of NR chains at larger elongation and the ionic crosslinks are two of the main reasons for the high tensile strengths of the NR/ZDMA composites, and they afforded the apparent tensile strength at different temperature range. Strain–stress curves revealed that the composites could not undergo strain-induced crystallization above 80°C. The results of Rubber Process Analyzer 2000 (RPA2000) confirmed that the effective ionic crosslinks were weakened and destroyed by high temperatures. The crosslink density, determined by an equilibrium swelling method, was used to characterize the structure variation during stretching at different temperatures. At last, the results of thermal gravimetric analysis (TGA) indicated that the ionic crosslinks improved the thermal stability of the NR/ZDMA composites to some extent. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

This work demonstrates an approach of in situ reactive compatibilization between polypropylene (PP) and ethylene-propylene-diene monomer (EPDM) by using ZDMA as a compatibilizer and, simultaneously, as a very strong reinforcing agent. With 7phr ZDMA in the PP/EPDM (30/70, w/w) thermoplastic vulcanizate (TPV), the tensile strength and elongation at break were increased from 5.3 MPa and 222% up to 11.2 MPa and 396%, respectively. Increasing the PP concentration further improved mechanical properties of the TPVs with ZDMA. This tremendous reinforcing as well as the compatibilization effect of the ZDMA was understood by polymerization of ZDMA and ZDMA reacting with EPDM and PP during peroxide induced dynamic vulcanization. A peculiar nano-composite structure that the crosslinked rubber particles were “bonded” by a transition zone which containing numerous of nano-particles with dimensions of about 20–30 nm was observed from transmission electron microscopy (TEM). Scanning electron microscopy (SEM) results showed that increase of PP/EPDM ratio reduced the size of crosslinked EPDM particles. Moreover, we found that the ZDMA reinforced EPDM particles resulted in a higher tan δ peak temperature for EPDM phase and built “filler-filler”-like networking in the PP melt. POLYM. COMPOS. 34:1357–1366, 2013. © 2013 Society of Plastics Engineers

Attempts were made to prepare the polypropylene (PP) /ethylene-propylene-diene monomer (EPDM) blends with zinc dimethacrylate (ZDMA) via peroxide dynamic vulcanization. PP was melt-mixed with EPDM and ZDMA at different compositions (PP/EPDM/ZDMA, i.e., 70/30/0, 70/30/3, 70/30/6, and 70/30/9, w/w/w) using an internal mixer at 50 rpm rotor speed. The addition of ZDMA improved the rheological properties of the resulting materials in the melt state. The morphological studies revealed that the addition of ZDMA led to an improvement of size reduction and distribution uniformity for crosslinked EPDM phase. ZDMA showed a positive effect on the mechanical properties of the PP/EPDM/ZDMA composites, particularly on the toughness and extensibility. With the incorporation of ZDMA, the izod impact strength and the elongation of PP/EPDM/ZDMA composites increased from 41 kJ/m² to 72 kJ/m² and 110% to 495%, respectively. The crystallization behaviors analysis indicated that the addition of ZDMA promoted the nucleation process of PP but the crystallinity of the PP phase was decreased at the meantime. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

The stress softening effect of nature rubber (NR) reinforced by in situ prepared zinc dimethacrylate (ZDMA) was studied. Degree of stress softening effect (Ds) in the 4th stress–strain cycle of the NR with 10 phr (parts per hundreds of rubber) ZDMA was only 2.23 (strain = 100%), whereas it reached to 59.98 at 50 phr ZDMA (strain = 200%). The stress softening effects of carbon black filled into NR, and compared with the ZDMA effect, was also studied here. Mooney–Rivlin semiempirical equation was introduced here to analysis the stress–strain behavior of the NR vulcanize filled with in situ prepared ZDMA, and the results showed that the ZDMA/NR system has an obvious Payne effect which is in good agreement with the stress softening effect. Crosslink density analysis indicated a high ionic crosslink density in the NR filled with high content ZDMA, which contributed to the low elastic recovery of the stress softening. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

This article dealt with the relationship between mechanical properties and crosslinked networks of natural rubber (NR) reinforced by zinc dimethacrylate (ZDMA) after thermal aging. After thermal aging at the present experimental conditions, the covalent crosslink density showed a decrease all the time, whereas the ionic crosslink density was stable at 80°C but decreased at a higher temperature. The decrease in the total crosslink density after aging indicates the degradation of the crosslinked network. However, an experimental phenomenon observed was that the tensile strength and tear strength increased in a certain degree after aging at 80°C or at a 100°C for a short time. In addition, the thermal stability of the NR/ZDMA composite was evaluated by thermal gravimetric analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

In this article, we study the evolution of networks based on natural rubber (NR) which is reinforced by in situ magnesium dimethacrylate (MDMA) during curing at a molecular level. The crosslink density of the compounds cured for different time was evaluated by a dissolution/swell experiment. The curing process was analyzed by using a UR-2030 Rotorless Rheometer. Mechanical properties of the composites cured for different time were also used to evaluate the evolution of the networks. The results reveal that the ionic crosslinks, cooperating with some primary covalent crosslinks and some other physical crosslinks, play an important role in supporting the crosslinked backbone of the composite to bear the external force in the initial curing time. The evolution of crosslinked networks could be divided into three regions in this particular experiment: network forming period dominated by the ionic bonds, fundamental network forming period, and ionic bonds rupture period. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Zinc dimethacrylate (ZDMA) can be polymerized during peroxide curing to form the polymerized ZDMA (PZDMA) at nanoscales. At the same time, the covalent crosslink of the rubber matrix and ionic crosslink introduced by the graft-PZDMA also are formed. The structure evolution of this type of composites is complex. In this article, the dynamic viscoelasticity characteristics of lightly cured ZDMA/natural rubber (NR) composites were investigated using a Rubber Process Analyzer 2000 (RPA2000). Our goal was to study the internal structures of this type of composites in an early curing stage. The dynamical viscoelasticity of the composites cured for 1 min was focused. The results of RPA2000 indicated that the PZDMA could act as particles to form a strong filler–filler structure which resulted in apparent Payne effect. A “primary network” structure might be formed which contained covalent crosslink points, ionic crosslinks, physical adsorption, and PZDMA. The stress-softening behavior was also investigated. At last, the scanning electron microscope analysis verified that most of the ZDMA had been polymerized to form PZDMA “nanoparticle” when the composites were cured for 1 min. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

In this article, the dynamic viscoelasticity characteristics of the natural rubber (NR)/magnesium dimethacrylate (MDMA) composites with different cure extent are investigated using a Rubber Process Analyzer 2000 (RPA2000). A weak filler–filler network of MDMA is formed in the uncured compounds. MDMA polymerize during peroxide curing and change to the polymerized MDMA (PMDMA), which can aggregate to form strong filler network in the lightly cured composite. The ionic crosslinks and NR crosslinks influence the dynamic viscoelasticity characteristics of the MDMA/NR composites with different cure extent significantly. Although the PMDMA aggregates have strong attraction with each other to form filler network, the ionic crosslinks are not favorable to rebuild the PMDMA network when the NR crosslink network is mature. Finally, the torque verifies that the ionic crosslinks can be influenced by small strain magnitudes (<0.1°) whereas the NR crosslink network is not influenced. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Peroxide dynamically vulcanized thermoplastic olefin (TPO) based on polypropylene (PP)/ethylene–propylene–diene (EPDM) loaded with zinc dimethacrylate (ZDMA) was prepared. The addition of ZDMA improved the complex viscosity of the resulting materials in the melt state significantly, as determined from oscillatory rheology analyses. Dynamic mechanical analysis (DMA) and transmission electron microscopy (TEM) examinations were performed to evaluate the structure of the PP/EPDM/ZDMA composite. Atomic force microscope (AFM) and scanning electron microscopy (SEM) were used to study the morphology. The degree of crystallinity was evaluated using X-ray diffraction method (XRD). The results revealed that incorporation of ZDMA resulted in a size reduction of the rubber droplets and improved the compatibility between rubber and PP phases. The nanoparticles of the polymerized ZDMA (PZDMA) served as an effective nucleating agent for the crystallization of PP. The rheological properties and mechanical properties were improved by ZDMA. Particularly, the izod impact strength of the PP/EPDM/ZDMA (80/20/6, w/w) composite is nearly 2 times higher than the PP/EPDM (80/20, w/w) and 12 times higher than the PP; besides, the elongation at break of the PP/EPDM/ZDMA (80/20/6, w/w) is 3 times higher than that of the PP/EPDM (80/20, w/w) and 6 times higher than the PP. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

In this paper, the dynamic mechanical properties of the natural rubber (NR) which was filled with in situ zinc dimethacrylate (ZDMA) were investigated using a Rubber Process Analyzer (RPA2000). A weak rigid filler–filler network was formed in the uncured NR/ZDMA compounds. Pronounced Payne effect and stress-softening behavior were observed in the vulcanizates, which indicated that a strong and special filler structure was formed after vulcanization. However, an ionic network might be formed with a high ZDMA loading, which was not favorable to rebuild the poly-ZDMA network. Finally, two tentative regions of networks deformation during the dynamic strain sweep were discussed: filler–filler and ionic bonds dominating region and rubber network dominating region. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

In this article, we investigated the evolution of the crosslink networks in nature rubber (NR) which is filled with in situ zinc dimethacrylate (ZDMA) during vulcanization. The results revealed that a primary network dominated by the ionic bond could be formed in the first 1 min, while the backbone of the covalent crosslink network was not formed. The ionic crosslinks, cooperating with some other physical crosslinks and some primary covalent crosslink points, play an important role in supporting the crosslink backbone of the composite in this period. This primary network was strong enough to bear the force exerted by the moving die of the Rheometer and to enable the composite that do not dissolve in toluene. After that, both the covalent crosslinking of NR molecules and polymerization of ZDMA react rapidly to give a birth to the fundamental network of the composites. Fourier transform infrared spectroscopy and differential scanning calorimeter were also used to investigate the curing reaction of the NR/ZDMA compounds. After ZDMA reaching a considerable conversion, the substantial covalent crosslinking reaction starts to be initiated. These results support the primary network dominated by the ionic bond formed in the first 1 min. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

In this article, we study the evolution of networks based on nitrile butadiene rubber (NBR) which is reinforced by in situ zinc dimethacrylate (ZDMA) during curing. The crosslink density of the composites cured for different time was evaluated by equilibrium swelling experiments. The curing process was analyzed by using a UR-2030 Rotorless Rheometer. Mechanical properties of the composites cured for different time were also used to evaluate the evolution of the networks. The results reveal that the covalent crosslinked network of NBR is formed rapidly in the early curing stage while the ionic crosslinks grow gradually during the whole curing process. The ionic crosslinks affect much more on the mechanical properties and make the composite easier to achieve inextensibility limit of the network. A sketch for formation of the NBR/ZDMA network was proposed in the last part of this article. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers