从离子交联的磺化乙丙橡胶制备热塑性互穿网络聚合物

研究了离子交联的磺化乙丙胶(简称离聚体)与聚丙烯、高密度聚乙烯或离子交联的磺化丁基胶共混物的熔融行为、力学性能与组成的关系以及其形态结构。结果表明,具有离子微区的上述弹性体与含有结晶微区的聚丙烯或聚乙烯生成热塑性互穿网络聚合物,在抗张强度上表现出明显的协同效应。参与共混的结晶聚合物的熔点随离聚体含量增加而下降,而在形态结构上则呈现交叉连续相,共混物呈现热塑性弹性体行为或增韧塑料行为。     

Biodegradable PPC/(PVA-TPU) ternary blend blown films with enhanced mechanical properties

Biodegradable films of poly(propylene carbonate)/poly(vinyl alcohol)-thermoplastic polyurethane [PPC/(PVA-TPU)] ternary blends were successfully prepared by melting blending method. The mechanical properties of poly(propylene carbonate) blown film were greatly improved by blending PPC with PVA-TPU. In order to afford the melt processing of PVA, the PVA-TPU binary blend was firstly prepared using thermoplastic polyurethane as a polymeric plasticizer. The rheological behavior, mechanical properties and morphology of these blends were studied. Considering its melt viscosity and thermally processing temperature, the PVA-50%TPU, as a modifier, was blended with PPC to prepare PPC/(PVA-TPU) ternary blend. SEM observation revealed a basic one-phase morphological structure with very good interfacial adhesion between the extremely blurred PPC and PVA-TPU two components. Meanwhile, the miscibility of the ternary components was verified by only one glass-transition temperature obtained from DMA tests. The tensile strength and tear strength of PPC/(PVA-TPU) blown films were determined at different temperatures. The results demonstrate that the mechanical properties of PPC/(PVA-TPU) films were enhanced dramatically at low temperature when compared with neat PPC. At room temperature, PPC/30 %(PVA-50%TPU) blown film exhibited a tensile strength of 26 MPa, and an elongation at break of 484.0 %. Its tear strength in the take-up direction is 124.1 kN/m, and the one in machine direction is 141.9 kN/m. At a low temperature of 0 °C, PPC/30 %(PVA-50%TPU) exhibited a tensile strength of 40.7 MPa and tear strength of 107 kN/m, which are 153 % and 142 % of those of neat PPC respectively. The blending of PPC with the PVA plasticized with TPU provides a practical way to extend the application of the new biodegradable polymer of PPC in the area of blown films.     

Synthesis and Characterization of Novel Thermoplastic Films for Removal of Heavy Metal Ions

The main objective of this study is to establish the applicability of novel thermoplastic films based on extracted gelatins from bovine (G_b) and bird (G_c) bones in addition to hide powder (HP), which blended with modified polyethylene (MPE) for the removal of heavy metal ions such as copper (II), chromium (VI), nickel (II) and zinc (II) from aqueous media. The chemical reaction between 2-oxoglutaric acid with furfural in presence of methyl amine, via Mannich reaction mechanism, resulted in chemical compound I. The chemical structure of product I was confirmed by different spectroscopic tools such as: nuclear magnetic resonance (¹³C- and ¹H-NMR) and Fourier transform infrared spectroscopy (FT-IR). The synthesized chemical product I was used as compatibilizing agent for blending G_b, G_c and Hp with MPE to obtain thermoplastic films using a polymer melting technique. The efficiency of the prepared films for absorption of different heavy metal ions from aqueous solution was investigated. The results indicated that the compatibilized films (MPE/I/HP) illustrated a maximum removal of zinc metal ions (～100%) under conditions of initial metal concentration about 240 mg/l. While, at initial metal concentration of about 150 mg/l, they exhibited excellent efficiency for removal of mixed metal ions of about 97–100% relative to the uncompatibilized ones (MPE/HP) 0%.     

添加剂改性壳聚糖膜性能的研究进展

壳聚糖膜具有良好的吸附性、抗菌性、生物相容性和生物降解性,因此应用非常广泛。通常交联剂能有效地提高壳聚糖膜的机械性能,减缓壳聚糖的降解速率和影响壳聚糖膜的吸附性;增塑剂可以改善壳聚糖膜的柔韧性,降低机械强度。壳聚糖与酯类复合,与高聚物共混改性,也可以明显改善壳聚糖膜的性能。本文综述了不同添加剂对壳聚糖膜的机械性能、吸附性和生物可降解性等的影响。     

Polyethersulfone/poly (butylene succinate) membrane: Effect of preparation conditions on properties and performance

In this study, biodegradable polymer of poly (butylene succinate) (PBS) was blended with polyethersulfone (PES) to prepare a novel semi-biodegradable membrane. The effect of blend ratio and coagulation bath temperature (CBT) was investigated on membrane characteristics including membrane morphology, mechanical strength and also treatment ability. Moreover, Fourier transform infrared (FTIR) spectrum, thermal stability, biodegradation and contact angle of the membranes were studied. Results demonstrated that the wastewater permeation through the prepared membranes was increased by blending the polymers and reached to maximum at blend ratio of 50/50. The wastewater treatment of PES/PBS blend membranes was improved by increasing PBS content.     

Biodegradation process of a blend of thermoplastic unripe banana flour—polyethylene under composting: Identification of the biodegrading agent

Starch‐based biodegradable polymers are obtained by incorporating plant‐derived polymers into plastics. This blending allows for a reduction in the polymer's resistance to microbial degradation. Assessing biodegradability is a key step in the characterization of newly designed polymers. Composting has been taken into consideration in waste management strategies as an alternative technology for plastic disposal. This study analyzed the biodegradability of an injection‐molded plastic material in which thermoplastic unripe banana flour (TPF) acts as a matrix (70%) and metallocene catalyzed polyethylene acts as a reinforcing filler (30%). This plastic was termed 70 TPF, and the structural, physical, and mechanical changes associated with its degradation were analyzed. The characterization of the microorganism that contributes to 70 TPF biodegradation was also performed. After composting, 70 TPF decreased in tensile strength and the TPF moiety in the blend was lost, greatly affecting the microstructure of the sample. Based on these indicators of degradation, this study identified the fungus Mortierella elongata as the microorganism responsible for the degradation of the plastic, a finding that supports the role of fungal communities in the biodegradation of designed materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42258.     

PCL/TPS/PE三元共混物的制备及性能研究

采用具有优异生物降解性能的聚己内酯(PCL)与热塑性淀粉(TPS)、聚乙烯(PE)进行共混复合，以得到加工性、力学性能、生物降解性优良的生物降解塑料。同时对其熔融流动性、力学性能、耐水性进行了研究。结果表明：加入PCL可有效改善材料的熔体流动性；PCL／TPS／PE三元共混物具有良好的综合性能。     

PVA/接枝改性淀粉热塑性生物降解材料的制备及应用

以过硫酸铵为引发剂,采用固相法合成了乙酸乙烯酯(VAC)/玉米淀粉接枝共聚物.将其与聚乙烯醇(PVA)、加工助剂在流变仪中共混,制备了PVA/接枝改性淀粉热塑性生物降解材料;分别研究了淀粉接枝共聚物对PVA/淀粉/接枝改性淀粉共混物的加工流动性、耐水性、力学性能和生物降解性能及形态结构的影响.结果表明,PVA/淀粉/接...     

Thermoplastic interpenetrating polymer networks of a triblock copolymer elastomer and an ionomeric plastic. I. Rheology and morphology

The thermoplastic interpenetrating polymer networks (IPNs) are combinations of two physically crosslinked polymers. Thermoplastic IPNs were prepared by combining polymer I, an SEBS triblock elastomer with polymer II, an ionomer prepared from a random copolymer of styrene, methacrylic acid, and isoprene (90/10/1 by volume). Neutralization of the acid groups to form the ionomer was carried out on a Brabender Plasticorder. Two subclasses of the thermoplastic IPNs were identified. Chemically blended systems, prepared by a sequential polymerization method, were compared with compositionally equivalent mechanically blended systems prepared by melt blending the separately synthesized polymers. The chemically blended thermoplastic IPNs (CBT IPNs) exhibited lower melt viscosities than compositionally equivalent mechanically blended thermoplastic IPNs (MBT IPNs). Moreover, the melt viscosities of many of the CBT IPNs were even lower than that of either homopolymer component, leading to an explanation in terms of an unusually low value of the rubbery modulus front factor. Although both types of thermoplastic IPNs underwent a phase inversion during neutralization of polymer II, the phase inversions were often incomplete. Morphological studies revealed that more equal dual phase continuity existed in the MBT IPNs than in the CBT IPNs after ionomer formation.     

淀粉基聚乙烯醇完全生物降解塑料薄膜的结构与性能

通过优化工艺条件，制备了高淀粉填充量的淀粉／聚乙烯醇完全生物降解塑料薄膜，研究了提高淀粉用量对淀粉／聚乙烯醇（PVA）完全生物降解塑料薄膜的力学性能和耐水性影响；并分析了耐水改性助剂尿素用量对薄膜的吸水率和生物降解性能的影响。结果表明，通过先糊化、后共混、再交联的薄膜制备工艺过程，能够获得高淀粉填充量的淀粉／聚乙烯醇完全生物降解塑料薄膜；先糊化打破了淀粉颗粒的原有形态结构，促进了淀粉与聚乙烯醇的共混相容性，从而获得了优良的力学性能；耐水改性助剂尿素的使用，能够大幅度地降低材料的吸水率，同时提高材料的生物降解性和环境友好程度。     

HDPE/LLDPE/POE薄膜性能的研究

采用线型低密度聚乙烯（LLDPE）和热塑性弹性体乙烯-辛烯共聚物（POE）对高密度聚乙烯（HDPE）薄膜进行改性,研究了LLDPE和POE对共混体系薄膜力学性能、加工性能的影响,探讨了LLDPE增强HDPE的机理。结果表明,加入一定量LLDPE,使HDPE／LLDPE薄膜的拉伸强度较纯HDPE薄膜有所增加,而单位冲击破损质量则有所下降。当w（LLDPE）为15％时,HDPE／LLDPE薄膜的拉伸强度提高21．6％,薄膜的单位冲击破损质量降低23．0％。在HDPE／LLDPE/POE三元体系中,当w（POE）,w（LLDPE）分别为10％,15％时,薄膜的拉伸强度、单位冲击破损质量、断裂伸长率比纯HDPE薄膜分别提高2．3％,113％。36．0％,综合性能良好。     

S-P新型塑料生物降解性能的研究

以淀粉（Ｓｔａｒｃｈ）、聚乙烯醇（ＰＶＡ）为原料制备了共混交联塑料薄膜（Ｓ－Ｐ）,采用ＡＳＴＭ法与培养皿法测定Ｓ－Ｐ膜材料的生物降解性能。实验结果表明：以该材料制成的农膜可被微生物降解,其降解速率随淀粉含量的增加而增加,随交联剂含量的增加而降低。     

Ionomer/ionomer thermoplastic IPNs based on poly(n-butyl acrylate) and polystyrene

Thermoplastic interpenetrating polymer networks (IPNs) were prepared by combining poly(n-butyl acrylate) with polystyrene, both polymers crosslinked independently with acrylic acid anhydride (AAA). Decrosslinking of both polymers was carried out by hydrolysis of the anhydride bonds. Neutralization of the carboxylic acid groups to form the ionomer was carried out in a Brabender Plasticorder. Two subclasses of thermoplastic IPNs were studied: (1) Chemically blended thermoplastic IPNs (CBT IPNs) were prepared by synthesizing polymer II in polymer I in a sequential synthesis; (2) mechanically blended thermoplastic IPNs (MBT IPNs) were prepared by melt blending separately synthesized polymers. Rheovibron characterization revealed that of the two combinations, the CBT IPNs were better mixed than the MBT IPNs. Investigations of phase continuity via melt viscosity and modulus suggest that the CBT IPNs have some degree of dual phase continuity. Transmission electron microscopy suggests dual phase continuity and relatively small phase domains, 2000–5000 Å for the CBT IPNs. The mechanical properties from tensile and Izod impact tests showed that the CBT IPNs were stronger than the MBT IPNs.     

Thermoplastic interpenetrating polymer networks of a triblock copolymer elastomer and an lonomeric plastic. II. Mechanical behavior

Thermoplastic interpenetrating polymer networks, IPN's, are defined as combinations of two physically crosslinked polymers. A styrene-b-ethylene-co-butylene-b-styrene (SEBS) triblock elastomer was combined with an ionomer prepared from a random copolymer of styrene, methacrylic acid, and isoprene (90/10/1 by volume), and subsequently neutralized. Two subclasses of the thermoplastic IPN's were identified. A sequential polymerization method yielded the chemically blended thermoplastic IPN's (CBT IPN's). Melt blending of the separately synthesized polymers produced the mechanically blended thermoplastic IPN's (MBT IPN's). Stress-strain and Rheovibron characterization revealed that the CBT IPN's exhibited greater tensile strength and higher elongation at break, but lower moduli than the MBT IPN materials of the same overall composition. Analysis of moduli data with the theories of Takayanagi, Davies, Budiansky, and Kerner disclosed more equal dual phase continuity for the MBT IPN's than the CBT IPN's at each composition. The low modulus of the more rubbery CBT IPN compositions was attributed to a decrease in the effective chain end-to-end distance between crosslinks in the elastomeric (EB) center block, brought about by the synthetic method.     

Effects of jackfruit waste flour on the properties of poly(vinyl alcohol) film

A series of biodegradable polymer films based on poly(vinyl alcohol) (PVOH) and jackfruit waste flour (JWF) was prepared in the presence of water and glycerol and cast by a solution casting method. The JWF was introduced as a promoter of biodegradability. The blended films were evaluated for their tensile properties, water absorption, water vapor transmission rate (WVTR), and degradation behavior under different environmental conditions such as natural weathering and natural soil. The tensile strength (1.7–6.4 MPa) and elongation at break (13–108%) of the PVOH/JWF films were lower than those of unfilled PVOH film (26MPa and 238%). However, the Young's modulus values (157–196 MPa) of the PVOH/JWF films were higher than that of unfilled PVOH film (137 MPa). The PVOH/JWF blended films showed higher water absorption and WVTR, which increased with increasing JWF content. Biodegradability tests revealed that the presence of JWF stimulated the degradation rate and caused the weight loss and reduction in tensile properties of the PVOH/JWF blended films. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers     

β-TCP scaffold coated with PCL as biodegradable materials for dental applications

Requirements for an ideal scaffold include biocompatibility, biodegradability, mechanical strength and sufficient porosity and pore dimensions. Beta tricalcium phosphate (β-TCP) has competent biocompatibility and biodegradability, but has low mechanical strength because of its porous structure. Polycaprolactone (PCL) is a biodegradable polymer with elastic characteristics and good biocompatibility. In this study, β-TCP/PCL composites were prepared in different ratio and their morphology, phase content, mechanical properties, biodegradation and biocompatibility were investigated. After coating, surfaces of β-TCP scaffolds were covered with the PCL while some of the pores were partially clogged. The compression and bending strength of β-TCP scaffolds were significantly enhanced by PCL coating. The degradation rate of the scaffold in Tris buffer was reduced with higher content of the PCL coating. MTT and ALP assays showed that the osteoblast cells could proliferate and differentiate on PCL coated scaffolds as well as on bare β-TCP scaffolds. Based on the comprehensive analysis achieved in this study, it is concluded that the β-TCP/PCL composite scaffold fabricated with 40% β-TCP and 5% PCL exhibits optimum properties suitable for dental applications.     

聚氯乙烯／环氧化天然橡胶共混型热塑性弹性体的配方研究

重点研究环氧化天然橡胶（ＥＮＲ）的环氧化程度，ＰＶＣ／ＥＮＲ配比，硫化体系（交联剂及共交联剂），填充补强体系以及增塑剂对ＰＶＣ／ＥＮＲ共混型热塑性弹性体物理性能的影响。结果表明当ＥＮＲ的环氧化程度为５０ｍｏｌ％，ＰＶＣ／ＥＮＲ＝５０／５０，采用ＤＣＰ作交联剂，硫黄作共交联剂，在ＥＮＲ中充入适量的重质芳烃油，通过适宜的工艺条件和动态硫化方式，可制出力学性能较好的ＰＶＣ／ＥＮＲ共混型ＴＰＶ。     

热塑性聚氨酯改性PVC的研究

将自制的热塑性聚氨酯（５６６ＴＰＵ）和日本的Ｐａｎｄｅｘ Ｔ－５２６５ＴＰＵ、美国的Ｅｌｖａｌｏｙ７４１及Ｃｈｅｍｉｇｕｍｐ－８３等四种不同的高分子改性剂，在相同条件下分别与聚氯乙烯（ＰＶＣ）共混，其共混物通过ＤＳＣ、扫描电镜、Ｘ－射线衍射测试，并比较其力学性能和薄膜耐热性能。证实ＰＶＣ／５６６ＴＰＵ共混物是非结晶相态，Ｔｇ值最低，两者相容性最好，且性能优异，可作为医用或其他用途的合金材料。     

SBS/LDPE共混型热塑性弹性体的性能研究(Ⅱ)

选用苯乙烯-丁二烯-苯乙烯弹体(SBS)和低密度聚乙烯(LDPE)为主体材料,采用部分动态硫化法制备了一类性能良好的材料———SBS LDPE共混型热塑性弹性体(TPE),具有力学强度高,断裂伸长率大,可重复加工等特点,并研究了共混方法、硫化温度、硫化时间等工艺方面因素对动态硫化SBS LDPE热塑性弹性体力学性能的影响。     

Effect of ferric salt of orange peel solid fraction on photo-oxidation and biodegradability of LDPE films

The present study is concerned with accelerating photo-oxidation and biodegradability of low-density polyethylene (LDPE) film in the presence of orange peel solid fraction (OPS), especially its ferric salt (OPSFe). Orange peel was made free from essential oils and pigments and then turned into a fine powder. The rate of photo-oxidative degradation of pure LDPE film and the blend samples, containing OPS/OPSFe at 0?C5?wt% in combination with PE-g-MA as a compatibilizer at 1?wt% of LDPE, in exposure to artificial sunlight was monitored by determination of carbonyl index derived from FTIR spectroscopy and the variations in mechanical properties in terms of UV-irradiation time. The original and irradiated samples (300?h) were buried in agricultural soil simultaneously and their biodegradation was evaluated by weight loss measurement, optical microscopy, and also calculation of carbonyl index derived from FTIR spectroscopy. The results obtained revealed that OPSFe acts as a significant accelerator in photo-oxidation and subsequent biodegradation of LDPE in soil enviornment. It is concluded that by incorporating small amount of Fe³⁺ ions into the polymer blend, photo-oxidative degradation of LDPE film is much more developed. Increase in OPSFe loading contributes to enhance the rate of photo- and biodegradability of LDPE films.