超支化乙二胺三嗪聚合物对PPC/PBS共混体系的增强改性研究

以超支化乙二胺三嗪聚合物（HBETP）为改性剂，采用熔融共混法制备了聚碳酸亚丙酯（PPC）/聚丁二酸丁二醇酯（PBS）/HBETP共混物；利用动态热机械分析仪、热失重分析仪、电子万能试验机、旋转流变仪、扫描电子显微镜等，对其热性能、力学性能、流变性能、断面形貌等进行了表征。结果表明，当HBETP含量为0.5 %（质量分数，下同） 时，PPC/PBS/HBETP共混物在韧性基本保持不变的情况下，拉伸强度提高幅度最大，由7.56 MPa提高到11.22 MPa，增幅为49.6 %；HBETP的加入可以提高PPC/PBS的相容性，且适当的含量会使PPC/PBS的拉伸强度提升。     

Preliminary investigation of poly(ether sulfone)/poly(aryl ether ketone) containing 1,4‐naphthalene blends

The blends of poly(ether sulfone) and poly(aryl ether ketone) containing 1,4‐naphthalene were prepared by melt mixing in a Brabender‐like apparatus. The specimens for measurements were made by compression molding under pressure and then were water‐quenched at room temperature. The tensile strength, tensile modulus, elongation at break, thermal analysis, and scanning electron microscopy were each measured. The dependence of tensile strength, tensile modulus, and elongation at break on blend systems was obtained. The effects of composition and miscibility on the mechanical properties are discussed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 472–476, 2006     

聚乳酸/聚丁二酸丁二醇酯共混物的研究

通过熔融共混制备了聚乳酸(PLA)/聚丁二酸丁二醇酯(PBS)共混物,采用扫描电子显微镜、差示扫描量热仪、旋转流变仪对其相容性、热性能和黏度等进行了研究,并研究了PBS的加入对PLA力学性能的影响。结果表明,PLA和PBS之间是部分相容的,PBS的少量添加并不影响PLA的拉伸强度,且其冲击强度随着PBS含量的增加呈先上升后下降的趋势,当PBS含量为10份时,共混物的冲击强度最好;与纯PLA相比,共混物的黏度有所增加,且随着PBS含量的增加,共混物的黏度逐渐增大;PBS的添加起到异相成核作用,促进了PLA的结晶。     

Toughening of poly(propylene carbonate) by hyperbranched poly(ester‐amide) via hydrogen bonding interaction

Poly(propylene carbonate) (PPC) is a biodegradable alternative copolymer of propylene oxide and carbon dioxide. As an amorphous polymer with lower glass transition temperature around 35 °C, PPC shows poor mechanical performance in that it becomes brittle below 20 °C and its dimensional stability deteriorates above 40 °C; thus toughening of PPC is urgently needed. Here we describe a biodegradable hyperbranched poly(ester‐amide) (HBP) that is suitable for this purpose. Compared with pure PPC, the PPC/HBP blend with 2.5 wt% HBP loading showed a 51 °C increase in thermal decomposition temperature and a 100% increase in elongation at break, whilst the corresponding tensile strength remained as high as 45 MPa and tensile modulus showed no obvious decrease. Crazing as well as cavitation was observed in the scanning electron microscopy images of the blends, which provided good evidence for the toughening mechanism of PPC. The intermolecular hydrogen bonding interaction confirmed by Fourier transform infrared spectral analysis proved to be the reason for the toughening phenomenon. Copyright © 2011 Society of Chemical Industry     

Miscibility and properties of completely biodegradable blends of poly(propylene carbonate) and poly(butylene succinate)

Completely biodegradable blends of poly (propylene carbonate) (PPC) and poly(butylene succinate) (PBS) were melt‐prepared and then compression‐molded. The miscibilities of the two aliphatic polyesters, that is, PPC and PBS, were investigated by dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The static mechanical properties, thermal behaviors, crystalline behavior, and melt flowability of the blends were also studied. Static tensile tests showed that the yield strength and the strength at break increased remarkably up to 30.7 and 46.3 MPa, respectively, with the incorporation of PBS. The good ductility of the blends was maintained in view of the large elongation at break. SEM observation revealed a two‐phase structure with good interfacial adhesion. The immiscibility of the two components was verified by the two independent glass‐transition temperatures obtained from DMA tests. Moreover, thermogravimetric measurements indicated that the thermal decomposition temperatures (T_?5% and T_?10%) of the PPC/PBS blends increased dramatically by 30–60°C when compared with PPC matrix. The melt flow indices of the blends showed that the introduction of PBS improved the melt flowability of the blends. The blending of PPC with PBS provided a practical way to develop completely biodegradable blends with applicable comprehensive properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Melt characteristics,mechanical, and thermal properties of blown film from modified blends of poly(butylene adipate‐co‐terephthalate) and poly(lactide)

Blown films from poly(butylene adipate‐co‐terephthalate) and poly(lactide) (PLA) blends were investigated. The blends were prepared in a twin‐screw extruder, in the presence of small amounts of dicumyl peroxide (DCP). The influence of DCP concentration on film blowing, rheological, mechanical, and thermal properties of the blends is reported in this article. Rheological results showed a marked increase in polymer melt strength and elasticity with the addition of DCP. As a consequence, the film homogeneity and the stability of the bubble were improved. The modified blend films, compared with the unmodified blend, showed an improvement in tensile strength and modulus with a slight loss in elongation. Fourier transform infrared and gel results revealed that chain scission and branching were more significant than crosslinking when the DCP loadings in the blends were not higher than 0.7%. A reduction in melt temperatures of PLA was observed due to difficulty in chain crystallization. The concentrations of DCP strongly affected the melting temperatures but had an insignificant effect on the decomposition behavior of the blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Studies on the blends of CO2 copolymer. IV. Natural rubber/poly(propylene carbonate) systems

The blends of a carbon dioxide copolymer, poly(propylene carbonate)(PPC) with natural rubber (NR), were prepared and their mechanical properties and morphology were studied. The optimum formulation blend was obtained by orthogonal experiments. The tensile strength of the blend containing 30 phr PPC was 18.9 MPa, with an elongation at break of 755%. The factors such as PPC and dicumyl peroxide content, PPC molecular weight, sulfur content, curing time, and curing temperature responsible for controlling the mechanical properties were discussed. Transverse electron micrographs showed a two‐phase structure for this blend. Gel content data revealed that PPC was crosslinked. The phase stability of PPC in the blend improved because of the interpenetrating new work structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2140–2144, 2002     

端环氧基型超支化聚合物对PPC/PBS共混物的改性研究

以端环氧基型超支化聚合物（EHBP）为改性剂,采用熔融共混法制备了聚碳酸亚丙酯（PPC）/聚丁二酸丁二醇酯（PBS）/ EHBP共混物;通过动态热机械分析仪、热失重分析仪、力学性能测试、旋转流变仪、扫描电子显微镜等对其进行表征。结果表明,加入EHBP使PPC和PBS间的玻璃化转变温度差（ΔT_g）减小,表明其界面相容性得到改善;当添加0.5 %的EHBP时,PPC/PBS/EHBP共混物的拉伸强度提升了68.7 %,冲击强度提升了81.2 %;当添加1.0 %的EHBP时,断裂伸长率增加了74.9 %;共混物的复数黏度随EHBP添加量的增加而减小。     

Miscibility of segmented polyurethane/poly(vinyl chloride) blends

Miscibilities of segmented polyurethanes (SPUs) and poly(vinyl chloride) (PVC) or functionalized poly(vinyl chloride) (FPVC) were studied with dynamic mechanical analysis, differential scanning calorimetry, and X‐ray diffraction. Mechanical properties of the blends were also studied with tensile measurements. The miscibility of the blends depended greatly on the hard‐segment content of SPU and the existence of the functional groups. The combination of SPU with a low hard‐segment content and PVC with functional groups made the blend system miscible. Moreover, controlling the blend composition of SPU/FPVC allowed us to modify the mechanical properties of SPU, where the elongation at break was multiplied without a significant change in its tensile strength. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3022–3029, 2001     

Processability,property, and morphology of biodegradable blends of poly(propylene carbonate) and poly(ethylene‐co‐vinyl alcohol)

Biodegradable blends of poly(propylene carbonate) (PPC) and poly(ethylene‐co‐vinyl alcohol) (EVOH) were melt compounded in a batch mixer followed by compression molding. The processability, mechanical properties, thermal behavior, and morphologies of the blends were investigated with torque rheometer, Fourier transform infrared spectroscopy, tensile tests, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. Torque rheometry indicated good interfacial miscibility between PPC and EVOH phases, and then fourier transform infrared spectroscopy spectra demonstrated that a certain extent of hydrogen‐bonding interactions between PPC and EVOH matrix in the blends. A study of the mechanical properties and thermal behavior showed that the EVOH incorporation can significantly enhance the tensile strength, thermal stability, and crystallinity of the blends. Moreover, dynamic mechanical analysis and differential scanning calorimetry both revealed that PPC and EVOH were compatible to some extent. Further, scanning electron microscopic examination also revealed the good interfacial adhesion between EVOH and PPC phases. POLYM. ENG. SCI., 47:174–180, 2007. © 2007 Society of Plastics Engineers     

Mechanical and thermal properties of poly(butylene succinate)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) biodegradable blends

Biodegradable polymer blends of poly(butylene succinate) (PBS) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) were prepared with different compositions. The mechanical properties of the blends were studied through tensile testing and dynamic mechanical thermal analysis. The dependence of the elastic modulus and strength data on the blend composition was modeled on the basis of the equivalent box model. The fitting parameters indicated complete immiscibility between PBS and PHBV and a moderate adhesion level between them. The immiscibility of the parent phases was also evidenced by scanning electron observation of the prepared blends. The thermal properties of the blends were studied through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results showed an enhancement of the crystallization behavior of PBS after it was blended with PHBV, whereas the thermal stability of PBS was reduced in the blends, as shown by the TGA thermograms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42815.     

Recycled poly(ethylene terephthalate)/linear low‐density polyethylene blends through physical processing

Poly(styrene‐ethylene/butylene‐styrene) (SEBS) was used as a compatibilizer to improve the thermal and mechanical properties of recycled poly(ethylene terephthalate)/linear low‐density polyethylene (R‐PET/LLDPE) blends. The blends compatibilized with 0–20 wt % SEBS were prepared by low‐temperature solid‐state extrusion. The effect of SEBS content was investigated using scanning electron microscope, differential scanning calorimeter, dynamic mechanical analysis (DMA), and mechanical property testing. Morphology observation showed that the addition of 10 wt % SEBS led to the deformation of dispersed phase from spherical to fibrous structure, and microfibrils were formed at the interface between two phases in the compatibilized blends. Both differential scanning calorimeter and DMA results revealed that the blend with 20 wt % SEBS showed better compatibility between PET and LLDPE than other blends studied. The addition of 20 wt % of SEBS obviously improved the crystallizibility of PET as well as the modulus of the blends. DMA analysis also showed that the interaction between SEBS and two other components enhanced at high temperature above 130°C. The impact strength of the blend with 20 wt % SEBS increased of 93.2% with respect to the blend without SEBS, accompanied by only a 28.7% tensile strength decrease. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Poly(ether ether ketone)/poly(aryl ether sulfone) blends: Relationships between morphology and mechanical properties

Mechanical properties such as the tensile modulus, yield (break) strength, and elongation to break (or yield) are measured for multiphase poly(ether ether ketone) (PEEK)/poly(aryl ether sulfone) (PES) blends. Specimens with three different levels of thermal histories (quenched, as‐molded, and annealed) are prepared in order to study their effects on the mechanical properties of PEEK/PES blends. Synergistic behavior is observed in the tensile modulus and tensile strength of the blends in almost the whole range of compositions. The ductility of quenched blends measured as the elongation to break (yield) shows an unexpected synergistic behavior in the blend containing 90 wt % PEEK, although a negative deviation from additive behavior is observed in the rest of the compositions. A ductile–brittle transition is observed between 50 and 75 wt % PEEK in the blend. The ductile–brittle transition in as‐molded blends shifts to 75–90 wt % PEEK. Annealed blends show predominantly brittle behavior in the whole composition range. The experimental data are further correlated with the theoretically predicted results based on various composite models. Although the prediction based on these equations fails to fit the experimental data in the whole composition range, the simplex equations that are normally used for blends showing synergistic behavior produced a reasonable fit to the experimental data. The mechanical properties obtained for different blend compositions are further correlated with their morphology as observed by scanning electron microscopy. Morphological observation shows a two‐phase morphology in PES‐rich blends, which is an interlocked morphology in which the disperse phase is not clearly visible in PEEK‐rich blends, and a cocontinuous type of morphology for a 50/50 composition. Considerable permanent deformation of both the disperse and matrix phase, especially in the case of quenched tensile specimens, demonstrates the remarkable adhesion present between the two phases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2887–2905, 2003     

Effects of l‐aspartic acid and poly(butylene succinate) on thermal stability and mechanical properties of poly(propylene carbonate)

Poly(propylene carbonate) (PPC) was modified by l ‐aspartic acid (Asp) and poly(butylene succinate) (PBS). To assess the effects of Asp and PBS on the thermal stability, mechanical properties of PPC, different PPC/Asp, PPC/PBS, and PPC/PBS/Asp blends were prepared by twin‐screw extruder. The results indicated that the thermal stability improved with the Asp content increasing from 0.5 to 5%. With trace presence of 2% Asp, the degradation temperature of PPC was greatly increased upon extruding and the Yield strength and Young's modulus increased 62 and 849 times, respectively, at 20°C. The flexibility of PPC was effectively improved by blending with PBS, the PBS has no significant effect on the thermal stability of PPC until PBS up to enough amount. Besides the Asp additive in PPC/PBS blends not only improved the thermal stability PPC, but improved the interfacial compatibility of the blend. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42970.     

PPC/PDAP共混膜的制备和性能

将过氧化二异丙苯(DCP)置于特定温度下,引发邻苯二甲酸二烯丙酯(DAP)在聚碳酸亚丙酯(PPC)溶液中聚合,制备得到聚碳酸亚丙酯/聚邻苯二甲酸二烯丙酯(PPC/PDAP)共混膜。采用红外光谱仪(FTIR)、X射线衍射仪(XRD)、差示扫描量热仪(DSC)、热重分析仪(TGA)、万能试验机和水蒸气透过率测试仪对共混膜的红外吸收、结晶性、热、力学和阻隔性能进行了表征。结果表明,通过DAP的聚合,提高了PPC的结晶性,使PDAP在PPC基体中形成交联网络,提高了共混膜的热、力学和阻隔性能。相比纯PPC,当DAP含量为20%时,共混膜的玻璃化转变温度和拉伸强度分别提高了5.3℃和266%;当DAP含量为40%时,共混膜的失重5%热分解温度提高了50.9℃,透湿系数下降了25%,因此,阻隔性能得到了提升。     

聚碳酸亚丙酯-聚乳酸共混熔纺纤维的制备与性能

以乙烯-马来酸酐共聚物(ZeMac)作为反应性相容剂,利用熔融纺丝法制备了聚碳酸亚丙酯(PPC)-聚乳酸(PLA)共混纤维。通过傅里叶变换红外光谱仪、热重分析仪、差示扫描量热分析仪、纤维强伸度仪等分别研究了共混纤维的分子结构、热稳定性、相容性及力学性能。结果表明:PLA的引入较大地提高了PPC的力学性能,加入少量的ZeMac可以有效地改善PPC的热稳定性,同时也能够提高共混体系的相容性。当PPC-PLA与PPC-PLA-ZeMac体系组分质量比分别为70/30和70/30/0.7时,其抗拉强度分别为11.23 MPa和20.83 MPa,较未改性的PPC分别提高了6.5倍和12.1倍,同时还能保持较高的断裂伸长率。该项研究为完全可生物降解PPC熔融共混纤维的工业化提供了可能性。     

High Strength and Barrier Properties of Biodegradable PPC/PBSA Blends Prepared by Reaction Compatibilization for Promising Application in Packaging

Poly(propylene carbonate) (PPC)/poly(butylene succinate-co-butylene adipate) (PBSA) blends are prepared via melt mixing using a twin-screw extruder. A one-step method based on the reaction compatibilization mechanism is used to prepare PPC/PBSA/AX8900(ethylene-methyl acrylate-glycidyl methacrylate random terpolymer) blends. The films of blends are prepared by an extrusion blown film machine. Fourier transform infrared spectroscopy results show that there is a strong hydrogen bonding between PPC and PBSA. The epoxy group of AX8900 can react with molecular chains of PPC and PBSA. It is shown from the rheological behavior that AX8900 can extend the molecular chains and increase the compatibility of PPC and PBSA. The films of PPC/PBSA blends exhibit more orientation structure than pure PPC film. The tensile strength of machine direction and transverse direction for 70PPC/30PBSA/1AX8900 film is higher than that for pure PPC film. The PPC/PBSA/AX8900 films have similar excellent barrier properties, compared with PPC film. The modified Maxwell theoretical model is used to predict and analyze changes in film barrier properties.     

Blends of poly(ethylene terephthalate) and poly(butylene terephthalate)

Commercial grade poly(ethylene terephthalate), (PET, intrinsic viscosity = 0.80 dL/g) and poly(butylene terephthalate), (PBT, intrinsic viscosity = 1.00 dL/g) were melt blended over the entire composition range using a counterrotating twin‐screw extruder. The mechanical, thermal, electrical, and rheological properties of the blends were studied. All of the blends showed higher impact properties than that of PET or PBT. The 50:50 blend composition exhibited the highest impact value. Other mechanical properties also showed similar trends for blends of this composition. The addition of PBT increased the processability of PET. Differential scanning calorimetry data showed the presence of both phases. For all blends, only a single glass‐transition temperature was observed. The melting characteristics of one phase were influenced by the presence of the other. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 75–82, 2005     

Control and development of crystallinity and morphology in poly(β‐hydroxybutyrate‐co‐β‐hydroxyvalerate)/poly(propylene carbonate) blends

Two different methodologies (reactive blending and mechanical blending) for preparing blends of poly(β‐hydroxybutyrate‐co‐β‐hydroxyvalerate) (PHBV) and poly(propylene carbonate) (PPC) were used. The miscibility, chemical structure, thermal behavior, crystallinity, morphology, and mechanical properties of the blends were investigated with Fourier transform infrared spectroscopy, differential scanning calorimetry, polarized optical microscopy, scanning electron microscopy, and tensile tests. A certain extent of hydrogen‐bonding interactions between PHBV and PPC took place in the blends. The graft copolymerization was confirmed in the reactive system. The incorporation of PPC hampered the crystallization process of PHBV and evidently altered the morphology, and the effect was enhanced in the reactive blend. The mechanical properties of PHBV could be changed by 1–2 orders of magnitude by blending modification. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1427–1436, 2005     

Effect of thermal aging on the biodegradation of PCL,PHB‐V,and their blends with starch in soil compost

Different proportions of starch were blended with poly(β‐hydroxybutyrate)‐co‐poly(β‐hydroxyvalerate) (PHB‐V) or poly(ε‐caprolactone) (PCL) by extrusion, and the mechanical (maximum tensile strength, elongation at break and Young's modulus) and thermal properties (by differential scanning calorimetry) were determined. The biodegradability of the blends in soil compost was also assessed after thermal aging for 192, 425, and 600 h at different temperatures. The maximum tensile strength of the PCL50 blend (containing 50% starch) was 35% lower than that of PCL and that of the PHB‐V50 blend was 60% lower than that of PHB‐V without thermal aging. PHB‐V blends were more biodegradable than PCL blends. For the blends prepared, only the biodegradation of PHB‐V25 was affected by thermal aging. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3539–3546, 2003