Crystallization behavior of poly(butylene succinate)/corn starch biodegradable composite

The effects of corn starch (CS) filler and lysine diisocyanate (LDI) as a coupling agent on the crystallization behavior of a poly(butylene succinate) (PBS)/CS ecocomposite were investigated using differential scanning calorimetry. In isothermal crystallization, n values for pure PBS were from 2.33 to 2.82. On the other hand, both composites showed values of 3 < n < 4. In nonisothermal crystallization, the Avrami exponent varied from 2.12 to 2.55 for pure PBS, from 1.58 to 1.96 for the composite without LDI, and from 1.79 to 1.91 for the composite with LDI, depending on the cooling rate. There was not a large difference of the crystallization rate constant (k) as adjusted by the Jeziornay suggestion. The activation energy for nonisothermal crystallization was also calculated on the basis of three different equations (Augis–Bennett, Kissinger, and Takhor equations). However, the values of the activation energy were in contradiction with the results of the kinetics. The addition of the filler (CS) and coupling agent (LDI) affected the morphological structure of PBS spherulites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1107–1114, 2005     

Enzyme-modified proteins from corn gluten meal: Preparation and functional properties

Functional properties of proteins in corn gluten meal (CGM) can be improved by enzyme hydrolysis combined with membrane technology. CGM was treated with a protease (Alcalase), resulting in 30–50% of the proteins being converted to soluble peptides. Conversions were higher when CGM was pretreated with cysteine or sulfite. Solubility and clarity of the enzyme-modified proteins were better at higher degrees of hydrolysis (DH). Higher DH increased initial foam volume but decreased foam stability. Membrane filtration of the hydrolyzed CGM reaction mixture resulted in two peptide fractions, as determined by size-exclusion high-performance liquid chromatography. Protein solubility of the membrane-permeable fraction was 90–99% compared with 8% for unmodified proteins. Larger-pore membranes improved foaming but decreased solubility and clarity. Moisture sorption at a water activity of 0.97 was 3.75 g water per gram of enzyme-modified/ultrafiltered CGM, compared with 0.2 g/g for the unmodified CGM.     

完全生物降解塑料PBS共混改性综述

介绍了（PBS）的材料特性及其工业应用上的局限性,并在改性研究上主要以扩链反应挤出和淀粉共混改性两个方面做了介绍。在扩链反应挤出方面着重介绍了扩链剂的应用的进展,在淀粉改性方面则从淀粉结构上介绍了现阶段淀粉在应用上的研究进展。     

Biodegradable Blends From Plasticized Soy Meal,Polycaprolactone, and Poly(butylene succinate)

A synergistic effect of simultaneous plasticization and destructurization of soy protein in melt extrusion is studied using soy meal, glycerol, and urea. The combined effect of plasticization and destructurization yields thermoplastic soy meal (TSM) that is capable of chemical interactions with biodegradable polyesters. Melt‐compounded blends of TSM with biodegradable polyesters give new ductile bioplastics. The observed improvement in the properties of these blends might be due to two reason; the high elasticity of the destructured soy meal and the compatibility between the polyesters used. The synergistic effect of unfolding and destructurization of the protein by urea leads to high mobility in the protein chains of the soy meal.

     

PBS/PBAT共混型全生物降解材料的制备及其性能研究

通过熔融共混法制备了聚丁二酸丁二醇酯（PBS）/聚己二酸对苯二甲酸丁二酯（PBAT）共混物,用熔体流动速率法、扫描量热法、X射线衍射、扫描电镜法及力学性能测试等手段研究了PBS/PBAT共混物的熔体流动性、结晶性能、力学性能以及共混物相容性。结果表明,随着PBAT含量的增加,PBS/PBAT共混体系的拉伸强度先升高后降低,断裂伸长率不断提高,冲击强度先降低后提高;当PBAT含量为20 %（质量分数,下同）时,与纯PBS相比,断裂伸长率提高10倍,冲击强度提高82 %,而拉伸强度仅仅降低6 %。     

生物降解塑料聚丁二酸丁二酯的改性研究进展

对近年来国内外在聚丁二酸丁二酯(PBS)物理与化学改性方面的研究进展情况进行了综述,其中物理改性方面包括无机填料改性、成核剂改性、天然高分子材料改性和生物降解塑料改性等,化学改性方面包括脂肪族聚酯共聚、芳香族聚酯共聚、扩链改性、交联改性等。最后指出了目前PBS改性存在的问题,并对PBS在未来的发展方向作了展望。     

Mechanical properties and biomass carbon ratios of poly(butylene succinate) composites filled with starch and cellulose filler using furfural as plasticizer

Polymer composites consisting of poly(butylene succinate) (PBS) as matrix and corn starch (CS) or cellulose filler (CF) with a small amount of furfural (FR) from biomass were prepared by a hot‐pressing method at 120°C from a powder mixture. Mechanical properties of the composites' films were investigated using tensile test methods. The strain of these films was found to be developed by adding CS or CF and further improved by adding FR. The strain at break PBS with 15 wt % FR was improved by more than 16 times of that of PBS without FR. The biomass carbon ratios of polymer composites with oil‐based PBS (major component) and with biobased CS, CF, and FR were evaluated by ¹⁴C concentration ratio measured by accelerator mass spectrometry (AMS) based on ASTM D6866. PBS with 40 wt % CS or CF had a biomass carbon ratio of 31 and 36%, respectively. PBS with 15 wt % FR had a biomass carbon ratio of 3.4%. This deviation was confirmed by FR content calculated from the peak area of the ¹H‐NMR spectrum of PBS with FR which was 3.4%, almost the same as the biomass carbon ratio measured by AMS. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

生物可降解共聚物PBST和PBS的结构与结晶性能

利用核磁共振氢谱和广角X射线衍射法研究了生物可降解共聚物聚对苯二甲酸-共-丁二酸丁二醇酯(PBST)的结构及结晶性能,并与聚丁二酸丁二醇酯(PBS)进行比较。结果表明:PBST为无规共聚物,其晶体结构为三斜晶系,PBS为均聚物,为单斜晶系,PBST的结晶度和结晶尺寸均比PBS的小。     

Tailored biodegradable films via extrusion blow molding using PBS,PBAT, and TPS

Research to replace synthetic polymers with biodegradable polymers is on the rise because common plastics have generated serious ecosystem problems. Films with thermoplastic starch (TPS), poly(butylene succinate) (PBS), poly(butylene adipate-co-butylene terephthalate (PBAT), and citric acid (CA) were produced by blown extrusion. They were characterized by blow-up ratio (BUR), water vapor permeability (WVP), soluble ratio (SR), water sorption isotherm, and thermogravimetric (TG) techniques. Films were uniform and showed BUR > 205%. The different proportions of PBS and PBAT significantly influenced the WVP of the films. All samples had WVP with an order of magnitude similar to other blends with high starch content (10⁻⁶ g m⁻¹ day⁻¹ Pa⁻¹). CA efficiently decreased the WVP of the PBS/PBAT/TPS formulations (15/15/70% and 20/10/70% by mass) by 25.2% and 24.7% compared to the acid-free formulations. There was no significant difference in SR (19.0%–20.1%). These materials were sensitive to moisture since the equilibrium moisture content increased pronouncedly from water activity of 0.5. Films showed good thermal stability, with a maximum decomposition temperature close to pure polyesters. CA did not increase the thermal stability of blends, probably because of the low content used (0.1%). Given the outcomes of this study, these films could be deemed appropriate for applications in food packaging.     

可生物降解聚合物的发泡技术研究进展

介绍了可生物降解聚合物的发泡技术进展,包括聚乳酸、聚己内酯、二元醇二元羧酸脂肪族聚酯、聚乙烯醇等及其共混物、纳米复合材料等的发泡技术,涉及了超临界二氧化碳发泡技术、化学发泡剂发泡技术等。     

Use of lignin strengthened with modified wheat gluten in biodegradable composites

In this study, composites from alkali lignin and wheat gluten, modified with different percentages of sodium silicate, were prepared and characterized. Moreover, the addition of silica to the aforementioned composites was studied with the aim of improving the thermal and mechanical properties. The effect of wheat gluten percent and the extent of its modification on the blends properties were investigated via diametric tensile strength, thermomechanical analysis (TMA), scanning electron microscope (SEM), thickness swelling and thermogravimetric analysis (TGA). The results showed significant improvement in the diametric tensile strength, thickness swelling, uniformity in the fracture surface, and the shift of glass transition temperature (T_g) toward higher values with increasing wheat gluten percent and its modification extent. These results reflect the enhancement of interaction between alkali lignin and wheat gluten. Alkali lignin/wheat gluten blends filled with silica possessed distinguishable characteristics and improved diametric tensile strength, low thermal expansion, and high T_g. Interestingly, TMA results showed that high dimensional stability against heating (thermal expansion percent) could be obtained using 60% wheat gluten modified with 15% sodium silicate and filled with 10% silica. This sample showed the highest T_g and the lowest thickness swelling in addition to smooth, uniform, and glossy surface as shown from the SEM images and TMA charts. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

PBAT复合材料的改性研究进展

综述了近年来国内外可降解高分子材料(如聚羟基丁酸戊酸共聚酯、聚碳酸亚丙酯、聚丁二酸丁二酯和聚乳酸),天然高分子材料(如淀粉、纤维素和木质素),无机填充物(如蒙脱土、有机黏土、碳纳米管和碳酸钙),以及扩链剂等对聚己二酸-对苯二甲酸丁二酯(PBAT)复合材料的改性研究进展。通过熔融共混改性,复合材料的力学性能、热性能、熔体黏度和尺寸稳定性有了很大提高。最后对PBAT未来的研究进行了展望。     

RHA/PBS生物可降解塑料的性能研究

利用废弃资源稻壳灰(RHA)作为增强填料,与聚丁二酸丁二醇酯(PBS)进行熔融共混制备RHA/PBS生物可降解复合材料。使用硅烷偶联剂KH-560对RHA进行表面处理。采用力学性能测试、扫描电子显微镜和热重分析仪等对复合材料力学性能、界面相容性及热稳定性进行研究。结果表明:硅烷偶联剂改性后的RHA(RHA-KH)与基体PBS界面相容性更好,并且能够在一定程度上提升复合材料的力学性能和热稳定性;RHA-KH/PBS复合材料的综合性能得到了提高。     

Characterization of extruded films based on poly (butylene succinate) blends to utilize a partially degraded poly (butylene adipate-co-terephthalate)

Polymer blends can improve material processability and can be used to extrude partially degraded materials, such as expired poly (butylene adipate-co-terephthalate) (PBAT), which cannot be normally extruded. Therefore, in this study, the extrudability of PBAT that has passed its expiration date was restored by blending it with poly (butylene succinate) (PBS). Various polymer blends were extruded and characterized to achieve high-efficiency extrusion. The carbonyl indices in partially degraded PBAT and the corresponding control sample detailed the effects of 98 months of aging on molecular properties. The semicrystalline structure consisted of a mixed ordered arrangement of PBS and PBAT chains dispersed in an amorphous matrix. The microscopic images of the surfaces of the polymer films revealed defects and roughness, followed by an increase in the PBAT concentration in blends. Changes in mechanical properties and water vapor permeability correlated with the PBAT concentration in the blends. To avoid polymer loss, we reported a simple method for using PBAT that has passed its expiration date and cannot be extruded. The results revealed that the polymer films could be used in the packaging industry, especially in food and agricultural sectors.     

Crystallization Kinetics and Hydrophilicity Improvement of Biodegradable Poly(butylene succinate) in its Miscible Blends with Poly(ethylene oxide)

The spherulitic morphology and growth, overall isothermal crystallization kinetics and hydrophilicity of PBSU were investigated by POM, DSC and WCA measurements in its miscible blends with PEO. The Hoffman‐Lauritzen equation was employed to analyze the spherulitic growth rates of neat and blended PBSU, which show a crystallization regime transition between regime II and III. The overall crystallization rates of PBSU decreased with increasing crystallization temperature, regardless of blend composition, while the crystallization mechanism does not change. A significant improvement in the hydrophilicity of PBSU can be achieved by blending with different weight fractions of PEO, which may be essential for the practical application of PBSU/PEO blends.

     

共聚合改性可生物降解PBS

通过改变1,4-丁二醇(BD)与1,4-环己烷二甲醇(CHDM)的配比,将其与1,4-丁二酸(SA)进行熔融缩聚合制备可生物降解聚丁二酸丁二酯(PBS)及BD-SA-CHDM共聚物[P(BS-co-CHDM)]。表征了P(BS-coCHDM)的结构并研究了PBS及其共聚物的非等温结晶行为、晶体结构、结晶形态及力学性能。结果表明:Jeziorny法和莫志深法均可很好地描述P(BS-co-CHDM)的非等温结晶行为,与PBS相比,P(BS-co-CHDM)的结晶速率随CHDM含量的增加先增大再减小;P(BS-co-CHDM)的晶体结构与PBS相同,仍为单斜α晶,70℃等温结晶2 h后,球晶尺寸随P(BS-co-CHDM)中CHDM含量的增加而减小;y(CHDM)为20%时,P(BS-co-CHDM)的断裂拉伸应变达208.9%。     

Hydrolysis and solubilization of corn gluten by Neutrase

Hydrolysis and solubilization of corn gluten were performed using a commercial protease preparation Neutrase. The effects of substrate concentration, enzyme concentration, temperature, pH and hydrolysate amount on the degree of hydrolysis and solubility of corn gluten were investigated depending on processing time. Trials were conducted in a batch reactor and degrees of hydrolysis were computed using a pH‐stat method. Results show that solubility and degree of hydrolysis were almost linearly related in all process conditions applied except in the case of hydrolysate addition. Optimum conditions for hydrolysis and solubilization were obtained as 10 g L^?1 protein concentration, 4 mL L^?1 enzyme concentration, 45 °C and pH 6.5. The mechanism of the kinetics was explained by taking into consideration association binding between the enzyme and substrate. The kinetics of hydrolysis and solubilization for all experiments performed were represented by exponential association equations that have not been used in the literature before. Also, to illustrate the effect of process variables on hydrolysis and solubilization, some modelling studies were performed. Copyright © 2007 Society of Chemical Industry     

淀粉基生物降解材料的制备及其力学性能的研究

以淀粉、PVA、水、甘油和硼砂为原料制备了淀粉基全降解材料,对其力学性能进行了研究。结果表明,以30份水做增塑剂,加入25份PVA时,材料的拉伸强度和断裂伸长率分别从纯淀粉的25.80MPa和1.11%提高到31.78MPa和6.24%,同时应力-应变曲线表明,材料从脆性断裂转变为无屈服点的韧性断裂,说明PVA增韧作用明显;硼砂可以使PVA和淀粉发生交联,制得材料的拉伸强度可达43.37MPa,但材料韧性较差;甘油的加入虽可以使材料的断裂伸长率提高,但拉伸强度明显降低;同时加入硼砂和甘油,材料的强度和韧性同时得到改善,拉伸强度和断裂伸长率分别提高到36.26MPa和11.71%。     

Synthesis and characterization of biodegradable poly(butylene succinate‐co‐propylene succinate)s

Biodegradable polyesters such as poly(butylene succinate) (PBS), poly(propylene succinate) (PPS), and poly(butylene succinate‐co‐propylene succinate)s (PBSPSs) were synthesized respectively, from 1,4‐succinic acid with 1,4‐butanediol and 1,3‐propanediol through a two‐step process of esterification and polycondensation in this article. The composition and physical properties of both homopolyesters and copolyesters were investigated via ¹H NMR, DSC, TGA, POM, AFM, and WAXD. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (T_m), crystallization temperature (T_c), crystallinity (X), and thermal decomposition temperature (T_d) of these polyesters decreased gradually as the content of propylene succinate unit increased. PBSPS copolyesters showed the same crystal structure as the PBS homopolyester. Besides the normal extinction crosses under the polarizing optical microscope, the double‐banded extinction patterns with periodic distance along the radial direction were also observed in the spherulites of PBS and PBSPS. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

高相对分子质量聚丁二酸丁二醇酯的合成与表征

以丁二酸和丁二醇为原料,十氢萘为溶剂,在140~200℃反应12~14 h,进行直接聚合,合成了高相对分子质量聚丁二酸丁二醇酯(PBS)。用FTIR和1HNMR确定了产物为预期化学结构。考察了6种催化剂的催化效果,结果表明,催化剂的催化效果按SnC l2>Ti(OBu)4>Ti(iOPr)4>Sn(Oct)2>Zn(Ac)2≈p-TS顺序递减,SnC l2具有最高的催化效率,以它为催化剂得到的PBS数均相对分子质量达到79 000,产率达到96.0%。当PBS的数均相对分子质量达到40 000以上时,具有很好的力学性能,拉伸强度达到35 MPa,可代替通用塑料。PBS具有良好的生物降解性能,在45 d时生物降解量达到49%,可用作生物降解材料。