High-damping polyurethane/hollow glass microspheres sound insulation materials: Preparation and characterization

The high-damping property of polyurethane elastomers and the low density of the hollow glass microspheres (HGM) were used to prepare the sound insulation materials in the present work. The transmission loss (TL) was measured to evaluate the HGM content on the sound insulation properties. The experimental results showed that the addition of HGM improved the hardness and compression modulus of the HGM-filled polyurethane composites, and the loss factor (tan δ) of polyurethane composites were greater than 0.9. The average transmission loss (ATL, from 63 to 6300 Hz) reached 37.32 dB when the content of HGM was 10 wt%. The ATL of the HGM-filled polyurethane composites with 15 wt% HGM in the damping control region and the mass control region were 31.94 and 46.78 dB, respectively. The synergistic effect of the microphase separation, the interfacial effect and the rigidity of polyurethane composites resulted in the improvement on sound insulation property. The polyurethane composite has a great potential application for the field of sound insulation materials.     

填料对水性阻尼涂料性能的影响

研究了不同填料对水性阻尼涂料阻尼性能和隔声性能的影响。试验结果表明,以云母粉作为填料的水性阻尼涂料具有较好的阻尼性能;而以白炭黑作为填料的水性阻尼涂料则具备较优的隔声性能。同时,水性阻尼涂料的阻尼性能和隔声性能随着云母粉粒径的减小而提高;随着云母粉用量的增加,水性阻尼涂料的损耗因子值降低,共振频率提高。     

The mechanism for inorganic fillers accelerating and inhibiting the UV irradiation aging behaviors of rigid poly(vinyl chloride)

The UV irradiation aging behaviors of PVC composites with several inorganic fillers were studied through Fourier transform spectroscopy (FTIR), ultraviolet spectroscopy (UV‐Vis), differential scanning calorimeter (DSC), scanning electron microscopy (SEM), and mechanical property test. It was found that incorporation of a small amount of the inorganic fillers such as CaCO₃, talc and SiO₂ could hold up the UV aging behaviors of PVC. Those filler‐filled PVC composites sheets after 20 days UV irradiation maintain lower carbonyl index (CI) and good appearance of surfaces, as compared with the corresponding neat PVC sheets, ascribed to high reflection of those fillers to UV light. While montmorillonite (MMT) and pyrophyllite fillers could accelerate the UV aging behaviors of PVC, which could be concluded from both the sharp increase of the CI and lower T_g due to the chain scission reactions because of their high absorbance of these fillers to UV light in 290–400 nm. In these two PVC composites, UV irradiation caused the deterioration of their mechanical properties and the appearance of rough, cracked and chalked surfaces after 20 days UV irradiation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and characterization of poly(vinyl chloride)–continuous carbon fiber composites

In this article, we report on the preparation and characterization of novel poly(vinyl chloride) (PVC)–carbon fiber (CF) composites. We achieved the reinforcement of PVC matrices with different plasticizer contents using unidirectional continuous CFs by applying a warm press and a cylinder press for the preparation of the PVC–CF composites. We achieved considerable reinforcement of PVC even at a relatively low CF content; for example, the maximum stress (σ_max) of the PVC–CF composite at a 3% CF content was found to be 1.5–2 times higher than that of the PVC matrix. There were great differences among the Young's modulus values of the pure PVC and PVC–CF composites matrices. The absolute Young's modulus values were in the range 1100–1300 MPa at a 3% CF content; these values were almost independent of the plasticizer content. In addition, we found a linear relationship between σ_max and the CF content and also recognized a linear variation of the Young's modulus with the CF content. The adhesion of CF to the PVC matrix was strong in each case, as concluded from the strain–stress curves and the light microscopy and scanning electron microscopy investigations. The mechanical properties of the PVC–CF composites with randomly oriented short (10 mm) fibers were also investigated. At low deformations, the stiffness of the composites improved with increasing CF content. Dynamic mechanical analysis (DMA) was used to determine the glass‐transition temperature (T_g) of the PVC–CF composites. The high increase in the Young's modulus entailed only a mild T_g increase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Prediction of sound transmission losses for polymer/inorganic particle composites

The sound transmission losses of the three composites including the nanometer calcium carbonate‐filled polypropylene (PP/nano‐CaCO₃) composites, calcium carbonate‐filled acrylonitrile butadiene styrene (ABS/CaCO₃) composites, and hollow glass bead‐filled polyvinyl chloride (PVC/HGB) composites were estimated using the equation of sound transmission loss published previously. The estimated sound transmission losses were compared to the measured data from the sound insulation properties of the three composites measured under the sound frequency varying from 125 to 10⁴ Hz. The results showed that the calculated sound transmission losses were roughly close to the measured data from the three composites under the same conditions, especially in the case of low sound frequency; the values of the sound transmission loss of the PVC/HGB composites were higher than those of the PP/nano‐CaCO₃ composites and ABS/CaCO₃ composites under the same sound frequency, it should be attributed to the extra sound energy consumption was generated in the hollow spheres. POLYM. COMPOS., 36:2059–2065, 2015. © 2014 Society of Plastics Engineer     

Mechanical,thermal, and water uptake characteristics of woodflour‐filled polyvinyl chloride/acrylonitrile butadiene styrene blends

Woodflour‐filled composites based on polymeric blends of polyvinyl chloride (PVC) and super high‐impact grade ABS were developed. Mechanical, thermal, and water uptake characteristics of the PVC/ABS matrix and their wood composites were evaluated. In the case of PVC/ABS matrix, the blend at a mass ratio of 50/50 rendered the impact strength with a very high value of up to 65 kJ/m², noticeably higher than those of the parent resins, that is, 6 kJ/m² of PVC and 35 kJ/m² of ABS. Dynamic mechanical analysis thermograms showed two distinct glass transition temperatures (T_gs) that shifted toward each other indicating partial miscibility of the blends. Water absorption of the blends after 24 h immersion was low, that is, within the range of 0.04–0.2 wt % and exhibits a behavior closed to pseudo‐Fickian type. The obtained PVC/ABS wood composites exhibited an increase of flexural modulus as well as T_gs with an increase of woodflour content. Finally, impact strength of the PVC/ABS composites was significantly higher than those of PVC composites or polyethylene composites comparing at the same woodflour content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

聚合物基复合材料隔声性能的研究

分析了无机粒子填充聚合物复合材料的隔声原理，指出其隔声效果的改善可归因于粒子使声波多次折射、散射和绕射导致传播路径增加，以及粘弹性的改变令声能消耗增大。测试了几种聚合物基复合材料的隔声性能，结果表明，隔声效果服从质量定律，且含中空粒子的复合材料具有更优越的隔声性能。     

Cell morphology and property relationships of microcellular foamed pvc/wood-fiber composites

Wood-fiber composites make use of cellulose fibers as a reinforcing filler in the polymer matrix and are known to have a lower material cost and a higher stiffness than neat polymers. However, the lower material cost and enhanced stiffness of wood-fiber composites are achieved at the expense of other properties such as the ductility and impact strength. Since microcellular plastics exhibit a higher impact strength, higher toughness, and increased fatigue life compared to unfoamed plastics, microcellular foaming of wood-fiber composites will improve the mechanical properties of the composites and therefore increase the usefulness of the materials. In this paper, microcellular foamed PVC/wood-fiber composites with unique cell morphology and material composition are characterized. Microcellular structures are produced in PVC/wood-fiber composites by first saturating the composite samples with CO₂ under high pressure followed by rapidly decreasing the solubility of gas in the samples. The void fraction of the microcellular foamed PVC/wood-fiber composites is controlled by tailoring the composition of materials and the foaming process parameters. The results indicate that tensile and impact properties of microcellular foamed PVC/wood-fiber composites are most sensitive to changes in the cell morphology and the surface modification of fibers.     

Dynamic mechanical and mechanical properties of polypropylene/poly(vinyl butyral)/mica composites

Three-component composites consisting of polypropylene (PP) matrix, poly(vinyl butyral) (PVB) modifier, and mica filler at various ratios of matrix to modifies and a constant mica content (30 wt %) were prepared by using two different kinds of PVB, viz., PVB and PVB-P. By correlating with the morphology, the dynamic mechanical and mechanical properties of the composites are studied in detail. PVB component in PP/PVB/mica composites cannot display a reinforcing effect to PP/mica binary composites, while impact strength of the composites are reduced further. It associates with incompatibility between PP and PVB, and as well as higher glass transition temperature of PVB. For PP/PVB-P/mica composites, stiffness decreases and, meanwhile, impact strength increases when PVB-P content is 7 wt %. The improvement of impact strength on PP/mica binary composites at the composition is due to a little affinity between the PP matrix and the plasticizer of PVB-P. Moreover, a minor amount of PP-g-MA in the 63/7/30 PP/PVB/mica composites only acts as an adhesion promoter. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2003–2011, 1997     

Stabilizations of molecular structures and mechanical properties of PVC and wood/PVC composites by Tinuvin and TiO2 stabilizers

Three different UV stabilizers, 2‐(2H‐benzotriazol‐2‐yl)‐4,6‐ditertpentylphenol (Tinuvin XT833), 2‐(2H‐benzotriazol‐2‐yl)‐p‐cresol (Tinuvin P), or rutile–titanium dioxide (TiO₂) were incorporated into poly(vinyl chloride) (PVC) and wood/PVC (WPVC) composite, and mechanical and physical properties and photostabilities were monitored. The polyene and carbonyl sequences of PVC increased with UV weathering time and with presence of wood flour. The yellowness index increased because of polyene and carbonyl productions, whereas the brightness increased because of the photobleaching of lignin in wood. The photostabilities of PVC and WPVC could be improved through the use of UV stabilizers. Tinuvin P was recommended in this work as the most effective stabilizer for PVC and WPVC composites. The stabilization effect was interfered by presence of wood particles. The mechanical property changes corresponded well to the structural changes under UV for neat PVC. For WPVC composites, the presence of wood particles played more significant effect on the mechanical properties during UV aging than the UV stabilizer. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Calcium carbonate and wood reinforced hybrid PVC composites

In this article, poly(vinyl chloride) (PVC) sandwich‐structured hybrid composites with amorphous calcium carbonate and wood‐filled cores were obtained by compression molding. It has been determined that wood addition up to a weight ratio of 33% reported to the total filler amount is beneficial in improving both the inter‐filler and filler‐matrix interfacial adhesion, which alongside with the promoting of the amorphous PVC matrix crystallization is responsible for an increase up to 34% in the flexural strength of the composites, compared to unfilled PVC. The hybrid filled composites present up to 35% lower friction coefficients and up to 20% higher Brinell hardness values than the composites filled with calcium carbonate alone. Subsequently, wood addition determines an increase in the oxidation onset temperature for PVC and an increase with up to 20% in the sound and thermal‐insulative properties of the composites, compared to unfilled PVC. The dominating dispersive part of the composites surface energy aids in improving the mass and dimensional stability of the assembly to both water and dilute hydrochloric acid aqueous solutions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46317.     

Synthesis,characterisation and enhanced properties of polyimide/mica hybrid films

Polyimide/mica (PI/mica) hybrid films were prepared from pyromellitic dianhydride/4,4-bis(3-aminophenoxy)biphenyl (PMDA/4,3-BAPOBP) and mica in a solution of N,N-dimethylacetamide. The structure–property relationships of the composites were studied by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible spectroscopy and differential scanning calorimetry. FTIR indicated successful preparation of PI/mica hybrid films. XRD and SEM results indicated that the mica was well dispersed in the PI matrix. The dependence of morphology, glass transition temperatures (T_g), dielectric properties and mechanical properties at room temperature of the hybrid films on the content of mica was discussed. It was observed that T_g, the breakdown strength and tensile strength of the hybrid films, could be simultaneously increased when the mica content was lower than 8?wt-%. Meanwhile, the dielectric constant and dielectric loss of PI/mica hybrid films increased with the increase in the mica content.     

Sound insulation in polymer/inorganic particle composites. I. Theoretical model

The sound insulation behavior of inorganic particulate-filled polymer composites was analyzed by means of acoustics theory in this article to reveal the mechanisms of sound insulation. On the basis of it, a physical model of the sound wave transfer in the composite system was established, and a relevant transmission loss equation was derived. The transmission loss of the glass bead-filled polyethylene composites was estimated by using this equation. The results showed that the calculated transmission loss of the composites increased linearly with an increase of the glass bead volume fraction, and it increased nonlinearly with increasing sound frequency. The sensitivity of the transmission loss to the sound frequency was significant at low sound frequency. The transmission loss decreased nonlinearly with the size of added glass bead when the volume fraction was constant. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The experimental results and simulation of temperature dependence of brittle‐ductile transition in PVC/CPE blends and PVC/CPE/nano‐CaCO3 composites

The effect of chlorinated polyethylene (CPE) content and test temperature on the notched Izod impact strength and brittle‐ductile transition behaviors for polyvinylchloride (PVC)/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites is studied. The CPE content and the test temperature regions are from 0–50 phr and 243–363 K, respectively. It is found that the optimum nano‐CaCO₃ content is 15 phr for PVC/CPE/nano‐CaCO₃ ternary composites. For both PVC/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites, the impact strength is improved remarkably when the CPE content or test temperature is higher than the critical value, that is, brittle‐ductile transition content (C_BD) or brittle‐ductile transition temperature (T_BD). The T_BD is closely related to the CPE content, the higher the CPE content, the lower the T_BD. The temperature dependence of impact strength for PVC/CPE blends and PVC/CPE/nano‐CaCO₃ ternary composites can be well simulated with a logistic fitting model, and the simulation results can be illustrated with the percolation model proposed by Wu and Jiang. DMA results reveal that both PVC and CPE can affect the T_BD of PVC/CPE blends and PVC/CPE/nano‐CaCO₃ composites. When the CPE content is enough (20 phr), the CPE is more important than PVC for determining the T_BD of PVC/CPE blends and PVC/CPE/nano‐CaCO₃ composites. Scanning electron microscopy (SEM) observations reveal that the impact fractured mechanism can change from brittle to ductile with increasing test temperature for these PVC systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

NBR/CR-Based High-Damping Rubber Composites Containing Multiscale Structures for Tailoring Sound Insulation

High-damping acoustic composites with unique sound insulation feature is reported, demonstrating surprisingly stable soundproof properties over a wide bandwidth of frequency (63–6300 Hz) with good mechanical properties. The extraordinary acoustic properties are attributed to the multiscale synergy of lamellar and hollow structures by multifillers adding. The acoustic composites are designed and fabricated through a low-temperature one-time rubber mixing process using nitrile butadiene rubber(NBR), chloroprene rubber (CR) as matrix and mica powder (MP), hollow glass beads (HGB), and montmorillonite (MMT) as multifillers. The soundproof mechanism is discussed in detail. Results indicate that the synergism of damping and sound absorption behaviors in the composition has a considerable impact on the acoustic characteristics, which can be controlled by the blending ratio of NBR/CR matrixes and the multiscale structures of MP/HGB/MMT multifillers. The designed multifillers acoustic composites can adapt to broadband engineering noise control including walls in express train constructions, panels of vessel or aircraft cabins, and large transportation pipelines.     

Mechanical properties of high density packed silica/poly(vinyl chloride) composites

This article focuses on the preparation and mechanical properties of silica/poly(vinyl chloride) (PVC) composites enriched with 60% mass ratio of 130 nm and 30 nm silica sphere fillers. Silica particles were pre‐treated with silane, IO₇ T₇(OH)₃ (trisilanol isooctyl polyhedral‐oligomeric silsesquioxane) to prevent agglomeration. The dispersion and interfacial compatibility of silica particles in a PVC matrix were investigated by scanning electron microscopy. The composite mechanical properties were characterized by tensile test, revealing improved Young modulus and tensile strength. Compared to pure PVC, the stiffness of 30 nm and 130 nm silica/PVC composites is on average increased by 30–40%, respectively. Similar trend was observed for the composite tensile strength on the change of the silica size. In contrast, elongation at break decreased for both composites compared to pure PVC, for 15% in 30 nm and for 30% in 130 nm silica/PVC composite. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Comparison of ethylene‐propylene diene terpolymer composites filled with natural and synthesized micas

In this paper, EPDM/mica composites were prepared by filling synthesized mica and natural mica separately into ethylene‐propylene diene terpolymer (EPDM) using melt blending technique. Microstructures, electrical properties, gas resistance, and mechanical properties of two EPDM/mica composites were investigated systematically. FTIR show that hydroxyl groups exist on the surface of the micas. These structural hydroxyls could be active sites conducive to the surface modification of mica. XRD analyses reveal that the natural mica is crystalline and the synthesized mica is amorphous. After being modified with silane coupling agent Si69, mica was only exfoliated into smaller micron agglomerates dispersing in EPDM, but the dispersion of amorphous synthesized mica was better. So the EPDM/synthesized mica composite possessed better mechanical property, electrical insulation property, and gas permeability resistance. It is expected that better improvement would be achieved, if mica is exfoliated further into nanosheets dispersing in the rubber matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Mechanical,acoustic, and thermal performances of shear thickening fluid–filled rigid polyurethane foam composites: Effects of content of shear thickening fluid and particle size of silica

Shear thickening fluid (STF) features a rheological property, and rigid polyurethane (PU) foams feature low thermal conductivity and excellent acoustic insulation. In this study, an STF/PU rigid foam composite sandwich structure was designed using different contents (0, 0.5, 1, or 1.5 wt %) of STF that contained 14 nm, 40 nm, or 75 nm silicon dioxide (SiO₂). The effects of STF content and silica size on the cell structure, mechanical performance, acoustic absorption, and thermal performance of the STF/PU foam were explored. The test results show that STF/PU foam exhibited three characteristic acoustic absorption peaks, and the maximum acoustic absorption coefficient reached 0.841. STF addition increased compression, bending strength, and maximum acoustic coefficient, as well as initial mass loss temperature. STF-filled PU foam composites containing 14 nm and 40 nm SiO₂ had a mild rise in thermal insulation. The rigid STF/PU foam composites with a cell structure had the maximum thermal conductivity of 0.22 W m⁻¹ K⁻¹ and sound absorption coefficient of 0.841, which confirm that they are a good candidate for sound-absorbing energy conservation materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47359.     

Preparation and characterization of PVC/CsxWO3 composite film with excellent near-infrared light shielding and high visible light transmission

Near-infrared (NIR) shielding is essential not only in the building and automobile glass films but also in achieving energy conservation. However, effectively shielding NIR and maintaining high transmittance in the visible light region have been great challenges in the past decade. Recently, hexagonal cesium tungsten bronze (Cs_xWO₃) nanoparticles have been widely studied due to the excellent transparency in the visible light region and strong heat-shielding ability in the NIR region. Herein, a design concept of transparent polyvinyl chloride (PVC)/Cs_xWO₃ composite film, as a heat insulation material for glasses, was proposed. To achieve this purpose, the PVC/Cs_xWO₃ composite film was prepared by incorporating Cs_xWO₃ slurry with better dispersion than traditional Cs_xWO₃ nanoparticles powder into a transparent PVC matrix. By the UV-Vis-NIR spectrophotometer characterization, the PVC/Cs_xWO₃ composite film containing 2.1 phr Cs_xWO₃ slurry displays high blocking of NIR (78%) and high transmittance of visible light (76%). In order to further understand the actual heat insulation effect from the PVC/Cs_xWO₃ composite films, the indoor sunlight simulation test and outdoor cooling experiment with solar illumination variations were carried out, which both showed heat insulation that is superior to the antimony tin oxide and indium tin oxide thin films prepared in our previous work. In addition, the mechanical property of PVC/Cs_xWO₃ composite films shows almost no change with the increase of Cs_xWO₃ slurry. The PVC/Cs_xWO₃ composite films simultaneously achieve excellent shielding of NIR and high transmittance of visible light, which makes it an ideal material to alleviate the current building energy consumption issues.     

Influence of interfacial interactions on the properties of PVC/cellulosic fiber composites

The surface properties at the interface between thermoplastic and cellulosic fibers strongly influence the mechanical properties of plastic/cellulosic fiber composites. This paper examines the role of surface acid-base properties of plasticized PVC and cellulosic fibers on the mechanical properties of the composites. The acid-base surface characteristics of cellulosic fibers were modified by treating the fibers with γ-aminopropyltriethoxysilane (A-1100), dichlorodiethylsilane, phthalic anhydride, and maleated polypropylene. The empirical acid (K_A) and base (K_D) characteristics (i.e., electron donor/acceptor abilities) of untreated and treated fibers, as well as plasticized PVC, were determined using inverse gas chromatography (IGC) technique. These parameters were used to yield information on the acid-base pair interactions that were correlated with the tensile and notched Izod impact properties of the composites. Acid-base pair interactions have been found to be a valuable parameter in the design of surface modification strategies intended to optimize the tensile strength of the composites. By tailoring the acid-base characteristics of cellulosic fibers and plasticized PVC, a composite with equal tensile strength and greater modulus than unfilled PVC was developed. However, the acid-base factors did not correlate with tensile modulus, the elongation at break, and the notched Izod impact property of PVC/newsprint fiber composites. Aminosilane has been observed to be a suitable adhesion promoter for PVC/wood composites improving significantly the tensile strength of the composites. Other treatments (dichlorodiethylsilane, phtalic anhydride, and maleated polypropylene) were found to be ineffective, giving similar strength compared to the composites with untreated cellulosic fibers. FTIR spectroscopy results suggested that aminosilane was effective because treated cellulosic fibers can react with PVC to form chemical bonds. The resulting bond between PVC and cellulosic fibers accounts for the effectiveness of aminosilane, when compared with other coupling agents.