The effect of epoxidized natural rubber on mechanical properties of siliceous earth/natural rubber composites

Siliceous earth (SE) is a kind of mineral consisting of lamellar kaolinite, muscovite (aluminum silicate) and corpuscular silica. Natural rubber (NR) composites containing NR as matrix, epoxidized natural rubber (ENR) as compatibilizer and SE as filler were produced by latex coagulating process and cured using a conventional sulfuric system. Monsanto measurements have shown that the ENR accelerates the vulcanization reaction and gives rise to a marked increase of the torque. The results of physico-mechanical properties of NR vulcanizates show that, when SE modified by silane coupling agent and in the meanwhile adding 4 phr of ENR as compatibilizer, maximum tensile strength, elongation at break, reinforcing index (M300/100) of NR/SE vulcanizates were obtained. The dynamic-mechanical properties exhibit the addition of ENR can enhance wet grip characteristics and reduce rolling resistance by lowering tan δ values at 60 °C and increasing tan δ values at 0 °C of NR compounds. The overall results show that properties of SE-reinforced NR substantially improved by adding ENR as compatibilizer. The addition of silane coupling agent and combining an appropriate amount of ENR would be better choice to improve the properties of NR/SE compounds.     

Studies on epoxidized rubber seed oil as plasticizer for acrylonitrile butadiene rubber

The application of rubber seed oil (RSO) and epoxidized RSO (ERSO) as a plasticizer in acrylonitrile butadiene rubber (NBR) was studied using RSO and ERSO with different levels of epoxidation. The results indicated that ERSO could be used as a less leachable and low volatility plasticizer for NBR. The use of ERSO in NBR gave better abrasion resistance whereas the tensile strength and tear strength were comparable to those vulcanizates that contained dioctyl phthalate as a plasticizer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 668–673, 2003     

Influence of compatibilizers on the rheological,mechanical, and morphological properties of epoxidized natural rubber/polypropylene thermoplastic vulcanizates

In polymeric materials combining desirable properties, compatibility between constituent components of incompatible blends is necessary. The influence of two types of blend compatibilizers, a graft copolymer of maleic anhydride and polypropylene (PP) and phenolic‐modified PP, on the rheological, mechanical, and morphological properties of epoxidized natural rubber/PP thermoplastic vulcanizates was investigated at varied concentrations. All properties improved in a range of loading levels of compatibilizers at 0–7.5 wt % of PP. This was attributed to a chemical interaction between the different phases caused by the functionalized compatibilizers. Increasing chemical interaction between interfaces improved the interfacial tension and led to a microscale size of the dispersion. A decreasing trend in the properties was observed at compatibilizer levels higher than 7.5 wt % of PP because of segregation, which led to a third blend component dispersed in the PP matrix. The compatibilizers behaved as lubricants in the polymer melt flow. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermoplastic vulcanizates based on epoxidized natural rubber/polypropylene blends: Effect of compatibilizers and reactive blending

Epoxidized natural rubber (ENR) was prepared using the performic epoxidation method. TPVs based on ENR/PP blends were later prepared by melt‐mixing processes via dynamic vulcanization. The effects of blend ratios of ENR/PP, types of compatibilizers, and reactive blending were investigated. Phenolic modified polypropylene (Ph‐PP) and graft copolymer of maleic anhydride on polypropylene molecules (PP‐g‐MA) were prepared and used as blend compatibilizers and reactive blending components of ENR/Ph‐PP and ENR/PP‐g‐MA blends. It was found that the mixing torque, apparent shear stress and apparent shear viscosity increased with increasing levels of ENR. This is attributed to the higher viscosity of the pure ENR than that of the pure PP. Furthermore, there was a higher compatibilizing effect because of the chemical interaction between the polar groups in ENR and PP‐g‐MA or Ph‐PP. Mixing torque, shear flow properties (i.e., shear stress and shear viscosity) and mechanical properties (i.e., tensile strength, elongation at break, and hardness) of the TPVs prepared by reactive blending of ENR/Ph‐PP and ENR/PP‐g‐MA were lower than that of the samples without a compatibilizer. However, the TPVs prepared using Ph‐PP and PP‐g‐MA as compatibilizers exhibited higher values. We observed that the TPVs prepared from ENR/PP with Ph‐PP as a compatibilizer gave the highest rheological and mechanical properties, while the reactive blending of ENR/PP exhibited the lowest values. Trend of the properties corresponds to the morphology of the TPVs. That is, the TPV with Ph‐PP as a blend compatibilizer showed the smallest rubber particles dispersed in the PP matrix, while the reactive blending of ENR/PP‐g‐MA showed the largest particles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4729–4740, 2006     

Processability characteristics and physico‐mechanical properties of natural rubber modified with rubber seed oil and epoxidized rubber seed oil

The processability characteristics and physico‐mechanical properties of natural rubber (NR) modified with raw rubber seed oil and epoxidized rubber seed oil have been studied. The modified mixes showed higher scorch time and lower cure rate, crosslink density, and ultimate state of cure compared to an unmodified mix. The thermal stability of the vulcanizates was practically unaffected by the modification. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1413–1418, 2000     

辅助增塑剂环氧大豆油对丁腈橡胶/聚丙烯热塑性硫化胶性能的影响

研究了辅助增塑剂环氧大豆油对以偏苯三甲酸三辛酯为主增塑剂的丁腈橡胶/聚丙烯热塑性硫化胶的硫化过程、耐油性能及流变性能的影响。结果表明,加入少量环氧大豆油,较单独使用偏苯三甲酸三辛酯可制备出具有更低硬度、高耐油性和流动性好的热塑性硫化胶。环氧大豆油可使丁腈橡胶/聚丙烯热塑性硫化胶制品的表面更加光滑,保护其不被氧化,令其色泽更加鲜艳和透明。     

环氧化天然橡胶改性的丁苯橡胶/白炭黑复合材料的形态和性能

以环氧化天然橡胶为改性剂制备了丁苯橡胶/白炭黑复合材料,研究了环氧化天然橡胶对丁苯橡胶/白炭黑复合材料微观形态和力学、耐热、耐老化及动态力学性能的影响.结果表明,少量环氧化天然橡胶的加入改善了填料在橡胶基质中的分散,提高了丁苯橡胶/白炭黑复合材料硫化胶的定伸应力、拉伸强度、撕裂强度和耐磨性能,降低了其动态压缩疲劳生热速...     

Modification of rubber powder with peroxide and properties of polypropylene/rubber composites

Waste tire powder was functionalized in the presence of various concentrations of allylamine and benzoyl peroxide. Fourier transform infrared spectroscopy studies confirmed the presence of allylamine on the surface of the rubber powder. The surface energy of the functionalized rubber powder revealed that the introduction of allylamine onto the rubber powder surface increased the surface activity. Improvements in the tensile strength, elongation at break, and storage modulus were observed for polypropylene/modified rubber powder/maleic anhydride grafted polypropylene, and this was attributed to an improvement in the compatibility due to the chemical interaction between the rubber powder and compatibilizer. Evidence for the reaction between the rubber surface and compatibilizer was observed in Fourier transform infrared studies. This peroxide‐initiated monomer‐grafting technique is feasible for large‐scale processes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2237–2243, 2007     

Synthesis and properties of cross‐linked polymers from epoxidized rubber seed oil and triethylenetetramine

A series of epoxidized oils were prepared from rubber seed, soybean, jatropha, palm, and coconut oils. The epoxy content varied from 0.03 to 7.4 wt %, in accordance with the degree of unsaturation of the oils (lowest for coconut, highest for rubber seed oil). Bulk polymerization/curing of the epoxidized oils with triethylenetetramine (in the absence of a catalyst) was carried out in a batch setup (1 : 1 molar ratio of epoxide to primary amine groups, 100°C, 100 rpm, 30 min) followed by casting of the mixture in a steel mold (180°C, 200 bar, 21 h) and this resulted in cross‐linked resins. The effect of relevant pressing conditions such as time, temperature, pressure, and molar ratio of the epoxide and primary amine groups was investigated and modeled using multivariable nonlinear regression. Good agreement between experimental data and model were obtained. The rubber seed oil‐derived polymer has a T_g of 11.1°C, a tensile strength of 1.72 MPa, and strain at break of 182%. These values are slightly higher than for commercial epoxidized soybean oil (T_g of 6.9°C, tensile strength of 1.11 MPa, and strain at break of 145.7%). However, the comparison highlights the potential for these novel resins to be used at industrial/commercial level. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42591.     

Mechanical properties of maleic anhydride treated jute fibre/polypropylene composites

Abstract

The effect of maleic anhydride (MA) modification of jute fibre on the mechanical properties of jute/polypropylene (PP) composites was studied. Jute fibre, an environmental friendly, low-density renewable material was chemically modified with MA before the incorporation with PP to improve interfacial adhesion between them. Fourier transform infrared (FTIR) study showed that the C=C groups of MA attached to jute cellulose reacted with the PP matrix. Jute fibre/PP composite treated with MA displayed higher Young's modulus and dynamic storage modulus owing to the enhanced interfacial adhesion between the fibre and PP matrix. A scanning electron microscopy (SEM) study showed evidence of the enhanced adhesion and bridging in the interfacial region of the composite as the result of MA modification of jute fibre.     

Preparation of epoxidized acrylonitrile butadiene rubber and its compatibilization effect on water-swellable rubber composites

In this research, water-swellable rubbers (WSRs) were prepared by the blending of acrylonitrile butadiene rubber (NBR) with epoxidized acrylonitrile butadiene rubber (ENBR), precipitated silica, vulcanizing agents, and polyacrylic acid sodium (PAAS) as superabsorbent polymers (SAPs). ENBR was prepared with a molybdenum trioxide catalyst and a tert-butyl hydroperoxide oxidant through a free-radical reaction under specific conditions and was used as a compatibilizer to improve the interfacial adhesion of the NBR matrix and hydrophilic components of the WSRs. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to analyze the structure and properties of ENBR. The dispersion of silica and SAPs in the rubber matrix was investigated by transmission electron microscopy. The presence of ENBR enhanced the water-absorption properties of the WSRs. The NBR–ENBR composites exhibited a higher mechanical performance after water absorption than that without ENBR. Both the swelling ratio and the absorption rate increased with the ENBR content. When the weight ratio of NBR–ENBR was 25/75, an equilibrium swelling ratio of 172% (13% higher than that of the sample without ENBR) was obtained. Scanning electron microscopy analysis revealed that the addition of ENBR improved the compatibility between the SAPs and the NBR matrix. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47694.     

The influence of compatibilizers on nitrile-butadiene rubber and polypropylene (NBR/PP) blends

Four kinds of compatibilizers—chlorinated polyethylene (normal CPE), highly chlorinated CPE, maleic anhydride grafted with polypropylene (MP), and chlorinated polypropylene (CPP)—were used to study the influence of compatibilizing agents on the properties of nitrile-butadiene rubber and polypropylene (NBR/PP) blends, a kind of thermoplastic elastomer (TPE). The results show that the most proper amount of normal CPE, highly chlorinated CPE, MP, and CPP are 9, 8, 7, and 6 wt%, respectively, in the NBR/PP blends. The CPP was the best compatibilizer for NBR/PP blends among the four. NBR/PP blends obtained excellent properties of thermoplastic materials and can be molded with the general processing technologies for thermoplastics, such as injection, extrusion, blow molding, and the like. The mechanical properties are similar to that of Geolast, produced by Monsanto Company, and exceed the Chinese national criterion (GB7527-87). The tensile strength was 13.8 MPa; the elongation at break was 290%; and the compression set was 32%. After the blends were immersed in oil for 70 h, the tensile strength was 10.4 MPa, and the degree of oil absorption was 12%. The compatibility of the blends was consistent with the morphology from transmission electron microscopy (TEM).     

Physical properties and cure characteristics of natural rubber/nanoclay composites with two different compatibilizers

The effects of epoxidized natural rubber (ENR) and maleic anhydride‐grafted polybutadiene (PB‐g‐MA) as compatibilizers to rubber formulations with and without organo‐modified layered silicates are investigated. The physical properties and curing characteristics of composites are studied by moving die rheometer, rubber process analyzer, tensile, tear, and hardness testing. The state of organoclay intercalation was determined by X‐ray diffraction method. The addition of compatibilizers, especially ENR 50, results in further intercalation or exfoliation of the organoclay that increased the clay dispersion in the rubber matrix. ENR 50 with organo‐modified clay improves the physical properties and changes the curing profile. The addition of PB‐g‐MA without organoclay increases the tensile strength (σ_max) by increasing the stock viscosity of the rubber compound. Interestingly, simultaneous increase in hardness and σ_max is achieved in the presence of both compatibilizers, a characteristic that is difficult to achieve and sometimes required in rubber processing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Use of polymeric compatibilizers in polypropylene/calcium carbonate composites

The effects of compatibilizing agents on the mechanical properties, viscoelastic properties, and morphology of polypropylene filled with calcium carbonate composites are investigated. It is found that the use of PP-g-MA and PP-g-AA significantly increases the tensile strength and improves particle dispersion and interfacial adhesion. The higher effect of compatibilization is obtained by using PP-g-MA as a compatibilizer. The results on the dynamic thermomechanical properties, viscoelastic properties, and SEM pictures also support the improved interfacial characteristics. It is also found that there exists a limiting amount of PP-g-MA at about 5% beyond which a further increase in the tensile strength is not obtained. The use of untreated calcium carbonate or SEBS-g-MA does not allow films to be drawn for the purpose of testing.     

Influence of compatibilizers on mechanical properties,crystallization, and morphology of polypropylene/scrap rubber dust blends

Polypropylene blends containing a dispersed phase of scrap rubber dusts obtained from sport shoes manufacture; midsole (M, vulcanized EVA foam) and outsole (O, vulcanized rubber blend of NR, SBR, and BR) were studied. The influence of various compatibilizers on the mechanical properties of these blends were investigated. Significant development of impact strength was attained by using 6 and 10 phr of styrene–ethylene–butylene–styrene (SEBS) and maleic anhydride‐grafted styrene–ethylene–butylene–styrene (SEBS‐g‐MA) as compatibilizers for both compounds filled with midsole and outsole dusts. The tensile strength of each compound was slightly decreased when the compatibilizer loading increased, whereas the elongation at break was significantly increased. The enhancements of the impact strength and the elongation at break are believed to arise from reduction of interfacial tension between two phases of the rubber and the PP, which results in some reduction of the particle size of the fillers. Scanning electron microscopy (SEM) confirmed the evidence of the reduction of scrap rubber dust into small rubber particle sizes in the compound, and also showed the occurrence of some fibrils. Optical microscopy (crossed polars) observations suggested that the addition of the rubber dust resulted in a less regular spherulite texture and less sharp spherulite boundaries. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 148–159, 2002     

The comparison of properties of (rubber tree seed shell flour)‐filled polypropylene and high‐density polyethylene composites

The effect of varied rubber tree seed shell flour (RSSF) filler loadings on processing torque, mechanical, thermal, water absorption, and morphological properties of polypropylene (PP) and high‐density polyethylene (HDPE) composites has been studied. The addition of RSSF in the composites increased the stabilization torque in both PP‐ and HDPE‐based composites. Tensile strength, elongation at break, flexural strength, and impact strength show significant reduction when higher loading of RSSF was incorporated, while tensile modulus and flexural modulus were improved. The phenomenon was noted for both matrices, PP and HDPE, but HDPE‐based composites showed clear effects on the reduction of the mechanical properties compared with RSSF‐filled PP. Scanning electron microscopy of tensile fracture specimens revealed the degree of dispersion of RSSF filler in the matrices. At higher filler loadings, agglomerations and poor dispersion of RSSF particles were spotted, which induce the debonding mechanism of the system. Thermogravimetric analysis thermograms showed that both PP‐ and HDPE‐based composite systems with higher RSSF content have higher thermal stability, initial degradation temperature, degradation temperature, and total weight loss. Water absorption ability of the composites increases as the filler loading increases for both matrices. J. VINYL ADDIT. TECHNOL., 22:91–99, 2016. © 2014 Society of Plastics Engineers     

The effect of maleic anhydride modified polypropylene on the mechanical properties of feather fiber,kraft pulp,polypropylene composites

Composites made of feather fiber (Ff), kraft pulp fiber (Pf), polypropylene (PP), and maleic anhydride modified polypropylene (MaPP) were tested in tension and three‐point bend tests. Composite panels were compression molded from multiple plies of nonwoven, fabric‐like prepreg manufactured with wetlay papermaking equipment. Composites containing all four materials were manufactured with MaPP substitutions for PP of 0–10 wt % at 2 wt % increments. The best mechanical properties were observed with a substitution of 8 wt % MaPP. Composites containing either Pf or Ff were manufactured with MaPP substitutions for PP of 0, 4, and 8 wt %; mechanical properties improved with increases in MaPP content. The improvements in mechanical properties were attributed to fiber/matrix interface improvement by the addition of MaPP. Scanning electron microscopy revealed evidence of improved interfacial bonding on the tensile fracture surfaces. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3771–3783, 2004     

均匀设计优化环氧橡胶籽油的制备工艺

以橡胶籽油、甲酸和双氧水为原料,磷酸作催化剂,采用无溶剂法合成环氧橡胶籽油,采用均匀设计法研究了甲酸用量、反应时间及双氧水用量等对环氧值的影响。结果表明,最佳制备工艺条件为:橡胶籽油100 g,甲酸12.80 g,质量分数为30%的双氧水50.53 g,反应时间6 h,反应温度50～55℃,产品环氧值达11.68%。     

马来酸酐接枝 SEBS对聚丙烯 / 碳纳米管复合材料性能的影响

采用球磨和熔融共混法，制备了聚丙烯（PP）／碳纳米管（CNT）／马来酸酐接枝SEBS（MA－SEBS）复合材料，结果表明，MA－SEBS促进了CNT在PP基体中的分散，形成完善的逾渗网络，改善了PP／CNT复合材料的抗静电性，提高了CNT对PP的增强作用，对PP／CNT复合材料有明显的增韧作用。     

Modification of oil palm empty fruit bunches with maleic anhydride: The effect on the tensile and dimensional stability properties of empty fruit bunch/polypropylene composites

Oil palm empty fruit bunch (EFB)‐filled polypropylene (PP) composites were produced. The EFB filler was chemically modified with maleic anhydride (MAH). The effects of the filler size and chemical modification of EFBs on the tensile and dimensional stability properties of EFB–PP composites were studied. The composites with MAH‐treated EFBs showed higher tensile strengths than those with untreated EFBs. This was attributed to the enhanced compatibility between the MAH‐treated EFBs and PP matrix, as shown in a scanning electron microscopy study. Fourier transform infrared analysis showed evidence of C?C and C?O bonds from MAH at 1630 and 1730 cm^?1, respectively. The MAH‐treated PP composites showed lower water absorption and thickness swelling than those with untreated EFBs. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 827–835, 2003