共查询到19条相似文献,搜索用时 125 毫秒
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PVA/淀粉薄膜挤出吹塑工艺及性能研究 总被引:2,自引:0,他引:2
采用挤出造粒和吹塑工艺连续制备了聚乙烯醇/淀粉薄膜.探讨了淀粉含量、增塑剂含量、增塑剂中水含量和混料条件对PVA/淀粉薄膜加工温度、熔体流动性和薄膜力学性能的影响.结果表明,随着淀粉含量的增加,增塑剂含量的增加,物料的加工温度降低;随着增塑剂中水含量的增加,挤出造粒温度升高,吹膜温度不变;PVA/淀粉共混物优选的造粒温度是165~180℃.吹膜温度是205~220℃;淀粉含量为35%~50%,增塑荆含量60份以上,增塑剂中的水含量为1/6~1/3时,共混物有较好的加工流动性;分批逐滴加入增塑剂并在80~110℃下混料,可以使PVA/淀粉充分溶胀.利于热塑性加工;淀粉含量为40%、增塑剂含量为60份、增塑剂中的水含量为33%时,薄膜力学性能最佳. 相似文献
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《合成树脂及塑料》2017,(6)
以热塑性木薯淀粉(TPS)为研究对象,甘油或甲酰胺/尿素为增塑剂,通过熔融共混法制备TPS/聚乙烯醇(PVA)共混物,利用热重分析仪研究增塑剂种类、用量及PVA对TPS热降解行为的影响。结果表明:添加甘油的TPS热降解温度高于添加甲酰胺/尿素复配增塑剂;随着甘油用量的增加,TPS热降解温度降低;添加PVA后,TPS热降解温度降低,且随着PVA用量的增加而降低;TPS热降解过程分为3个阶段,TPS/PVA共混物的热降解分为4个阶段;随着升温速率的增加,TPS的热降解温度升高;采用Kissinger研究了TPS/PVA共混物的热降解动力学,PVA的加入降低了TPS的热降解活化能。 相似文献
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热塑性淀粉/黄麻复合材料的研究 总被引:1,自引:0,他引:1
以玉米淀粉为原料,以甘油和尿素为增塑剂制备了热塑性淀粉(TPS),并与黄麻(F)进行共混制备了复合材料(TPS/F).对共混条件以及黄麻用量对材料力学性能和耐水性的影响进行了研究.结果表明:在转矩流变仪中转速越高越有利于淀粉的塑化.以尿素为增塑剂制备的热塑性淀粉(UTPS)的拉伸强度(13 MPa)高于以甘油为增塑剂的热塑性淀粉(GTPS)的拉伸强度(7 MPa),而在加入黄麻后,当黄麻质量分数为20%时,GTPS/F的拉伸强度高达26.8 MPa,高于UTPS/F.黄麻的加入也提高了UTPS的耐水性,但GTPS的耐水性仍较差. 相似文献
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乙酰淀粉/PBS/PVA共混体系流变性能及力学性能研究 总被引:1,自引:0,他引:1
采用转矩流变仪模拟了乙酰淀粉/聚丁二酸丁二醇酯(PBS)/聚乙烯醇(PVA)三元共混体系的挤出加工过程,考察了PBS/PVA比例、增塑剂、转速、温度对共混体系转矩流变性能的影响;通过电子扫描显微镜观察了共混物的表面形态,并进行了力学性能表征。结果表明:在160℃、转速15r/min条件下,每50phr乙酰淀粉加入10phr甘油、30phrPVA和10phrPBS,共混体系具有较好的流变性能;PVA和PBS的适量加入可有效改善共混物的力学性能。 相似文献
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The starch/polyvinyl alcohol (PVA) bioblend sheets containing urea and formamide as plasticizers were prepared through melt processing in presence of water. The experiments indicated that urea and formamide plasticizers could form strong hydrogen bonds with starch/PVA molecules. Urea exhibited better plasticizing effect than formamide. Urea also could greatly destroy the crystal structures of PVA component in the blends, leading to the decreased crystallinity of the blends. Formamide was a good solvent for urea and could prevent urea separating from the blends, resulting in the improved stability of plasticizing systems. The blends exhibited good flexibility. Therefore, the incorporation of both urea and formamide into starch/PVA blends could exhibit synergistic effects to ensure the blends with both good plasticizing effect and the stability of the plasticizing systems. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42311. 相似文献
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Two series of biodegradaable polyvinyl alcohol (PVA)/starch blends, i.e., PVA with/without plasma treatment (PP/P series), were produced by single‐screw extruder. The influences of plasma pretreatment and PVA content on the tensile properties, thermal behaviors, melt flow index, and biodegradability of blends were investigated. PVA pretreated by plasma (PPVA) reacted with glycerol was found not only to mechanically strengthen the PPVA/starch blend but also to improve the compatibility of PPVA and starch. Compared with PVA/starch blends, the melt flow indices of PPVA/starch blends were improved significantly by 200–300% and their tensile strength also increased two‐to‐three‐fold. Thermogravimetry analysis (TGA) showed that the thermal stability of PPVA/starch (85/300g) blend was better than PVA/starch blend at processing temperature and outperformed than PVA and starch at high temperature. Both the PPVA/starch and PVA/starch blends finished biodegradation within 9–10 weeks in soil burial tests. The esterification reaction of PPVA and glycerol was characterized by FTIR spectroscopic measurement and TGA test. The morphologic evolutions of the blend during biodegradation were investigated carefully by scanning electron microscope (SEM) imaging. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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B. Sreedhar M. Sairam D. K. Chattopadhyay P. A. Syamala Rathnam D. V. Mohan Rao 《应用聚合物科学杂志》2005,96(4):1313-1322
Starch–poly(vinyl alcohol) (PVA) blends with different compositions were prepared and crosslinked with borax by in situ and posttreatment methods. Various amounts of glycerol and poly(ethylene glycol) with a molecular weight of 400 were added to the formulations as plasticizers. The pure starch–PVA blends and the crosslinked blends were subjected to differential scanning calorimetry, thermogravimetry, and X‐ray photoelectron spectroscopic studies. Broido and Coats–Redfern equations were used to calculate the thermal decomposition kinetic parameters. The tensile strengths and elongation percentages of the films were also evaluated. The results suggested that the glass‐transition temperature (Tg) and the melting temperature strongly depended on the plasticizer concentration. The enthalpy relaxation phenomenon was dependent on the starch content in the pure blend. The crosslinked films showed higher stability and lower Tg's than pure PVA and starch–PVA blends, respectively. High‐resolution X‐ray photoelectron spectroscopy provided a method of differentiating the presence of various carbons associated with different environments in the films. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1313–1322, 2005 相似文献
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Compatibility of starch/polyvinyl alcohol (PVA) blends, prepared by solution cast method, is dependent on the blend composition. Crystallinity of the blend, as measured by X‐ray diffraction (XRD) and differential scanning calorimeter (DSC), decreases with increase in starch content. Thermogravimetric analysis (TGA) shows that the broadness in the peak width at the degradation region increases with increase in starch content in the starch/PVA blend. Dynamic mechanical thermal analysis (DMTA) reveal that the broadness of the relaxation peaks is due to the partial compatibility of the glycerol plasticized starch/PVA blends. The tensile property decreases with increase in starch content and the 30/70 starch/PVA blend shows maximum ductility in respect to both the percentage of elongation and energy at break. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers 相似文献
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Super‐tough biodegradable poly(vinyl alcohol)/poly(vinyl pyrrolidone) blends plasticized by glycerol and sorbitol 下载免费PDF全文
Phetdaphat Boonsuk Kaewta Kaewtatip Sirinya Chantarak Antonios Kelarakis Chiraphon Chaibundit 《应用聚合物科学杂志》2018,135(26)
Tough biodegradable films were prepared using a poly(vinyl alcohol) (PVA)/poly(vinyl pyrrolidone) (PVP) (1:1) blend with plasticizers of glycerol (GLY), sorbitol (SOR), and their (one to one) mixture. We studied the effect of plasticization on the structural, thermal, and mechanical properties of the PVA/PVP blend films. Fourier transform infrared spectra indicated good miscibility of the two components due to the H‐bonding between the PVA and PVP molecules. The addition of plasticizers reduced the interaction between PVA and PVP, evidenced by an increase in the intensity of PVA diffraction peaks observed in the X‐ray diffraction (XRD) characterization. Thermal degradation of the blends increased as a function of the plasticizer used. GLY affected thermal degradation more than SOR and the mixtures. The incorporation of the plasticizers promoted the growth of PVA crystals as evidenced by XRD patterns and the enthalpy of fusion (ΔHf) obtained by differential scanning calorimetry measurements. The introduction of SOR to the binary blend increased toughness seven times and imparted simultaneous and pronounced improvements to maximum tensile stress and elongation at break. This behavior holds out great promise for the development of a new generation of mechanically robust, yet thoroughly biodegradable materials that could effectively supplant conventional polymers in demanding applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46406. 相似文献
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Dynamic mechanical properties of photopolymerizable poly(vinyl alcohol) (PVA)–monoacrylate blends were investigated by measuring dynamic shear modulus G′ and loss tangent, tan δ. The dynamic mechanical properties of the blends before being exposed to UV irradiation were governed by the weight percent of the monomers which act as plasticizers. On the other hand, the UV-irradiated blends seemed to be typical two-phase materials since they revealed two tan δ maxima whose positions were independent of the monomer content. Those two maxima were assigned to PVA and photopolymerized acrylates with reference to the dynamic mechanical data of PVA and a PVA-polyacrylamide polyblend. Those dynamic mechanical data suggested that insolubilization of the blend type photopolymers should be caused by a decrease in solubility due to graft polymerization of acrylate monomers onto PVA. 相似文献
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H. L. Abd El‐Mohdy 《应用聚合物科学杂志》2007,104(1):504-513
Starch‐based plastic films were prepared by the electron beam irradiation of starch and poly(vinyl alcohol) (PVA) in a physical gel state at room temperature. The influence of starch/PVA composition, irradiation dose, and plasticizer (glycerol) on the properties of the plastic films was investigated. The gel fraction of the starch/PVA films increased with both the radiation dose and PVA content in the plastic film and decreased with increasing glycerol concentration. The starch/PVA compatibility was determined by measurement of the thermal properties of the starch/PVA blends with various compositions with differential scanning calorimetry. The swelling of the starch/PVA films increased with increasing PVA content and decreasing irradiation dose. Mechanical studies were carried out, and the tensile strength of the films decreased at high starch ratios in the starch‐based mixture. This was due to the decrease in the degree of crosslinking of starch. Furthermore, when PVA, a biodegradable and flexible‐chain polymer, was incorporated into the starch‐based films, the properties of the films, such as the flexibility (elongation at break), were obviously improved. The tensile strength of the films decreased with increasing glycerol concentration, but elongation at break increased up to a maximum value at a 20% glycerol concentration, and then, it leveled off and decreased slightly. Biodegradation of the starch/PVA plastic films was indicated by weight loss (%) after burial in soil and morphological shape, which was detected by scanning electron microscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 504–513, 2007 相似文献