Amylose–polyester block copolymers

The synthesis of amylose–polyester block copolymers is described. 2,3,6-Tri-0-allyl amylose was synthesized by amylose alkoxide and allyl bromide and hydrolyzed by hydronium ions to give an hydroxyl-terminated allyl amylose oligomer (HTAA). The allyl groups were isomerized with t-BuoK to yield the prop-1-enyl isomer (HTPA). The HTPA was capped with a diisocyanate. The HTPA prepolymer was reacted with hydroxy-terminated poly(ethylene-co-propylene adipate) and poly-(ethylene terephthalate) to form block terpolymers. Block terpolymer formation was demonstrated by intrinsic viscosity increases, gel permeation chromatographic results, and infrared (IR) and PMR spectroscopy. The products were depropenylated by HgCl₂ to yield amylose block terpolymers. These polymers were readily degraded by α-amylase.     

Biodegradable Cellulose Block Copolymers

Biodegradable polymers can be prepared by the incorporation of cellulose oligomeric blocks into the polymer backbone. Block copolymers prepared by reacting equimolar amounts of depolymerized cellulose triacetate (CTA) with MDI or TDI and block terpolymers prepared by reacting the CTA oligomer with poly (propylene glycol) capped with MDI or TDI were deacetylated and incubated with cellulysin at pH 5 and 50 °C. The intrinsic viscosity of each copolymer decreased substantially even after 10 hr incubation time. There was negligible acid hydrolysis. Cellulose showed a smaller decrease at the same incubation time-probably due to its lower accessibility. Methods for incorporating cellulose oligomeric blocks and other biodegradable blocks into different types of polymers are discussed.     

Rheology of hydrophobically modified polyacrylamide-co-poly(acrylic acid) on addition of surfactant and variation of solution pH

Constant shear and shear dependent viscosity measurements are reported in aqueous systems of co- and terpolymers of acrylamide (AM), N-n-alkylacrylamide (C10, C12, and C14 alkyl groups), and acrylic acid (AA) with added anionic surfactant sodium dodecyl sulfate (SDS). The results are presented as three-dimensional plots of viscosity vs surfactant concentration and pH at constant shear rate or viscosity vs shear rate and surfactant concentration at constant pH. For terpolymers incorporating AA, a strong viscosity maximum is observed at intermediate pH values (pH 4-6) where the AA groups are partially ionized and at SDS concentrations close to the critical micelle concentration. At high pH, all AA incorporating terpolymer solutions with SDS are strongly shear thinning, but at pH 3-4 the systems of terpolymers with SDS are strongly shear thickening at low shear, followed by a shear-thinning region at high shear. These results are explained in terms of surfactant-mediated network formation with polymer coil expansion and hydrogen bonding between partially ionized AA groups as additional factors.     

Ethylene copolymers with Fischer-Tropsch olefins

The properties of ethylene copolymers, terpolymers and multipolymers prepared with even and uneven carbon number linear and branched α-olefins were compared. The most likely microstructures of ethylene/linear α-olefin copolymers was assigned by considering co-unit bulkiness, average crystallizable sequence lengths and thermal properties. The higher α-olefins were found to be more effective at decreasing density, but peak melting temperatures were higher. In terpolymers where lower α-olefins such as 1-butene and 1-pentene were used as comonomers, density was decreased more than the mathematical average expected from the ratio of comonomers in the terpolymers. Peak melting temperatures were also lower. Based on NMR evidence and the microstructures of the different copolymers the rationale for this occurrence could be ascribed to decreased clustering for these terpolymers. Branched α-olefins produced ethylene co- and terpolymers with significantly decreased densities as compared to the linear α-olefins. Impact strength of these polymers was also substantially higher, even at low comonomer content. Thermal evidence indicates that the microstructure of the co- and terpolymers containing branched α-olefins are very similar to that of the copolymers prepared with linear α-olefins of the same carbon number.     

甲基丙烯酰氧基乙基三甲基氯化铵-丙烯酰胺-丙烯酸三元共聚物水溶液的盐效应研究

用恒定外加盐浓度稀释法,测定了甲基丙烯酰氧基乙三甲基氯化铵 丙烯酰胺 丙烯酸（ＤＭＣ ＡＭ ＡＡ） 三元共聚物（ＡＰＡＭ） 水溶液在分别添加不同种类外加盐时的特性粘数．实验结果表明,当外加盐浓度在一定范围内变化时,所有共聚物在ＮａＣｌ 溶液和ＮａＮＯ３ 溶液中均表现出典型的普通聚电解质粘性行为,而ＤＭＣ 和ＡＡ 近似等摩尔的共聚物在Ｎａ２ＳＯ４ 溶液中则呈现出典型的两性聚电解质粘性行为,各种外加盐对ＡＰＡＭ 溶液特性粘数影响的程度为：Ｎａ２ＳＯ４ ＞ ＣａＣｌ２ ,ＮａＮＯ３ ＞ ＮａＣｌ．     

Preparation and characterization of soluble terpolymers from m‐phenylenediamine,o‐anisidine,and 2,3‐xylidine

A series of terpolymers were synthesized by the chemical oxidative polymerization of m‐phenylenediamine (MPD), o‐anisidine (AS), and 2,3‐xylidine (XY) in hydrochloride aqueous medium. The yield, intrinsic viscosity, and solubility of the terpolymers were studied by changing the MPD/AS/XY molar ratio from 100/0/0 to 53/39/8 to 0/100/0. It was discovered that the MPD/AS/XY terpolymers exhibit a higher polymerization yield and better solubility than MPD/AS and MPD/XY bipolymers having the same MPD molar content. The as‐prepared MPD/AS/XY terpolymer bases were characterized by Fourier transform infrared, ultraviolet–visible, ¹H NMR, and high‐resolution solid‐state ¹³C NMR spectroscopies; wide‐angle X‐ray diffraction; and thermogravimetry. The results suggested that the oxidative polymerization from MPD, AS, and XY is exothermic, and the resulting terpolymers are more easily soluble in some organic solvents than MPD homopolymer. The copolymer obtained was a real terpolymer containing MPD, AS, and XY units, and the actual MPD/AS/XY molar ratio calculated by solid‐state ¹³C NMR spectra of the polymers is very close to the feed ratio, although the AS content calculated on the basis of the ¹H NMR spectrum of the soluble part of the polymer is higher than the feed AS content. The terpolymers and MPD homopolymer exhibit a higher polymerization yield and much higher intrinsic viscosity and are more amorphous than the AS homopolymer. At a fixed MPD content of 70 mol %, the terpolymers exhibit an increased thermostability and activation energy of the major degradation in nitrogen and air with an increasing AS content. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3989–4000, 2001     

Block copolymerization. V. Block anionic polymerization of lactams

Bischloroformates of hydroxy-terminated poly(tetramethylene glycol) (PTG) and polystyrene (PSt) were prepared and used as the initiators for the anionic polymerization of α-pyrrolidone and ε-caprolactam in bulk at 30°C and 80°C, respectively. Initiation efficiency was sufficiently high to give well-defined nylon–PTG(or PSt)–nylon block copolymers. Both the yield and the viscosity of the block copolymer increased with polymerization time up to 50% conversion of the lactam.     

Preparation and Evaluation of Some Terpolymers as Lube Oil Additives

In the present work, some polymeric additives were prepared to use as viscosity index improvers and pour point depressants for lube oil via copolymerization of hexadecylacrylate and dodecylacrylate with styrene. Structure of the prepared compounds was confirmed by infrared spectroscopy and nuclear magnetic resonance. The molecular weights of the prepared copolymers were determined by using gel permeation chromatograph. The efficiency of the prepared terpolymers as viscosity index improvers and pour point depressants for lube oil was investigation. It was found that all the prepared terpolymers are effective as viscosity index improvers and pour point depressants. The viscosity index of the prepared terpolymers increases with increasing the concentration of the additives and increases by increasing the percentage of hexadecylacrylate until 70%. The best result for viscosity index of the prepared terpolymers is when the percentage of styrene is 10%. The pour point of the prepared compound decreases with decreasing concentration of additive used.     

以丙烯为主体的二元及三元共聚研究──丙烯与乙烯和丁烯－1的共聚合

研究了ＭｇＣｌ２载体高效催化剂用于丙烯为主体的与乙烯和丁烯－１的二元及三元共聚合反应：选择了最佳的共聚合条件；实验测定了共聚单体配比对共聚合活性、共聚物分子量和物理性能的影响；并用１３Ｃ—ＮＭＲ分析了共聚物组成、序列分布和支链结构等微观结构信息．     

Kinetic studies of twisted intramolecular charge transfer in highly viscous solvents as a function of pressure and temperature

The viscosity and temperature dependences of TICT formation for two dialkylaminobenzonitriles are separated by comparing time-resolved fluorescence measurements with pressure and with temperature variation in glycerol and glycerol triacetate. From the identical decay behaviour observed and from the measured activation energies being smaller than that of solvent mobility it can be concluded that TICT formation occurs without intrinsic barrier in this case.     

Stimuli‐responsive ampholytic terpolymers of N‐acryloyl‐valine,acrylamide, and (3‐acrylamidopropyl)trimethylammonium chloride: Synthesis,characterization, and solution properties

Low‐charge density ampholytic terpolymers composed of acrylamide (AM), (3‐acrylamidopropyl)trimethyl ammonium chloride (APTAC), and N‐acryloyl‐valine were prepared via free‐radical polymerization in 0.5 M NaCl to yield terpolymers with random charge distributions. Sodium formate (NaOOCH) was employed as a chain transfer agent during the polymerization to suppress gel effects and broadening of the molecular weight distribution (MWD). Terpolymer compositions were determined by ¹³C NMR spectroscopy. Terpolymer molecular weights (MWs) and polydispersity indices (PDIs) were obtained via size exclusion chromatography/multi‐angle laser light scattering (SEC‐MALLS). Intrinsic viscosity values determined from SEC‐MALLS data using the Flory–Fox relationship were compared with those determined by low‐shear dilute solution viscometry and found to be in good agreement. SEC‐MALLS experiments allowed examination of radius of gyration‐MW (R_g‐M) relationships and the Mark‐Houwink‐Sakurada intrinsic viscosity‐MW ([η]‐M) relationships for terpolymers. The R_g‐M and [η]‐M relationships indicated little or no excluded volume effects under SEC conditions indicating that the terpolymers were in near theta conditions in an aqueous buffer solution. Potentiometric titration experiments were performed in deionized (DI) water. These studies revealed that the apparent pK_a of the AMVALTAC terpolymers increases with increasing VAL content. The solution properties of low‐charge density ampholytic terpolymers have been studied as functions of solution pH, ionic strength, and polymer concentration. The charge‐balanced terpolymers exhibit polyampholyte behavior at pH values ≥ 6.5. As solution pH is decreased, these charge‐balanced terpolymers become increasingly cationic due to the protonation of the VAL repeat units. Charge‐imbalanced terpolymers generally exhibit polyelectrolyte behavior, although the effects of intramolecular electrostatic interactions (e.g., polyampholyte effects) on the hydrodynamic volume are evident at certain values of solution pH and salt concentration. The solution behavior of the terpolymers in the dilute regime correlates well with that predicted by various polyampholyte solution theories. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3125–3139, 2006     

从二氧化碳和环氧丙烷及异氰酸酯合成聚亚氨碳酸酯

研究了二氧化碳，环氧丙烷和异氰酸酯的共聚合反应．并考察了反应条件，异氰酸酯加入量对共聚产率及共聚物的特性粘数、分子量分布及热稳定性的影响．实验发现，引入异氰酸酯具有扩链作用，而引入二异氨酸酯则具有明显的文化交联作用．由共聚物水解试验和光谱研究结果表明，共聚反应生成的是聚亚氨碳酸酯，而不是聚氨基甲酸酯．这种聚亚氨碳酸酯比聚碳酸亚丙酯具有较高的热稳定性．     

孪尾疏水缔合三元共聚物的粘度行为:水解度的影响

以十二烷基硫酸钠(SDS)为表面活性剂,利用氧化还原体系、采用前加碱共聚-共水解的方法制备了孪尾疏水缔合水溶性三元共聚物聚(丙烯酰胺／丙烯酸钠／N,N-二己基丙烯酰胺)[P(AM/NaAA／DiC6AM)],研究了P(AM／NaAA／DiC6AM)稀溶液及亚浓溶液的性能。随理论水解度的增加,P(AM／NaAA／DiC6AM)水溶液的特性粘数[η]增加,Huggins常数KH减小。P(AM／NaAA／DiC6AM)水溶液的表现粘度随理论水解度的增加而增加,随温度、剪切速率的增加而降低,随剪切速率的增加开始时降低较快而后变化较小。P(AM／NaAA/DiC6AM)在盐溶液中随NaCl、CaCl2质量浓度的增加,出现盐增粘现象;理论水解度不同的P(AM／NaAA／DiC6AM)与SDS水溶液的表现粘度在wSDS=0．050～0．400g／L范围内随SDS质量浓度的变化差别不大。     

高取代度淀粉醋酸酯的制备

改善淀粉热塑性的方法主要是用塑化剂对其进行处理和用化学方法制备淀粉衍生物,使羟基被长链取代,减弱淀粉分子间的氢键,大分子可在较低温度下运动,从而达到降低熔融温度的目的。近年来,对高取代度淀粉醋酸酯已有报道^[1-5],Sagar等^[2]认为,粉酯的取代度越高,侧链越长,热塑性和亲水性的改变就越明显,而且酯基可起到内增塑作用,可塑性的提高反映在材料的流变学,热学及力学性能的改变上,Maheras等^[3]用高取代度的淀粉醋酸酯和纤维素醋酸酯共混,制成了纤维和塑料制品,由于高取代度淀粉醋酸酯熔点较高,Brochers等^[4]提出通过加入分子量为100－1000的增塑剂,如甘油三醋酯等,可使熔融温度降到150℃左右,Tanaka等^[6]将淀粉和乙烯类化合物在酯化催化剂的作用下反应,得到的淀粉酯性能较为理想,分子量高,具有相当好的机械性能和耐水性,国外专利报道了以甲磺酸（MSA）为催化剂制备淀粉醋酸酯的方法^[7},但对其结构和性能尚未作系统的研究,本文以冰醋酸和醋酸酐为混合酸,MSA为催化剂,制得了具有较高取代度的高直链淀粉醋酸酯,并系统研究了反应温度,反应时间,反应物比例等不同反应条件对取代度的影响,通过红外分析,特性粘度测试,溶解性等分析手段,表征了高直链淀粉醋酸酯的结构与性能。     

Polymerization with TMA-protected polar vinyl comonomers. I. Catalyzed by group 4 metal complexes with η5-type ligands

This paper describes the use of several kinds of group IV Cp based catalyst systems, in the synthesis of co- and terpolymers of ethylene, propylene and α-olefins endowed with OH and COOH functional groups. The hydroxy monomers used were 5-hexen-1-ol (4) and 10-undecen-1-ol (5) and the carboxy monomer was 10-undecen-1-oic acid (6). The three catalyst systems used were the C₂ symmetric ansa-zirconocene (1) the “in-site” titanium complex (2) and the non-rigid zirconocene (3), all activated by methylaluminoxane. Trimethylaluminium was used to protect the functional group of polar monomers. The first two catalyst systems suffer similar activity loss in the presence of polar monomer whereas the third one exhibited better tolerance toward the hydroxyolefins. NMR and FTIR spectroscopies were used to characterize the polymerization products. All three catalyst systems afforded functionalized co- and terpolymers by direct polymerization of ethylene/propylene/hydroxy-α-olefins but only the catalyst system (1)/MAO displays appreciable activities for direct polymerization of ethylene, propylene and carboxy-α-olefins. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2457–2469, 1999     

Water-soluble polymers. 71. pH responsive behavior of terpolymers of sodium acrylate,acrylamide, and the zwitterionic monomer 4-(2-acrylamido-2-methylpropanedimethylammonio)butanoate

Terpolymers of sodium acrylate (NaA), acrylamide (AM), and the zwitterionic monomer 4-(2-acrylamido-2-methylpropanedimethylammonio) butanoate (AMPDAB) were prepared by the free radical polymerization in 0.5M NaBr aqueous solution using potassium persulfate as the initiator. The feed ratio of AMPDAB : NaA : AM was varied from 5 : 5 : 90 to 40 : 40 : 20 mol %, with the total monomer concentration held constant at 0.45M. Terpolymer compositions were determined by ¹³C NMR. Molecular weights varied from 3.0 × 10⁵ to 9.7 × 10⁶ g/mol. All terpolymers were soluble in deionized water and salt solutions at all pH values. The dilute and semidilute solution behavior of the terpolymers was studied as a function of composition, pH, and added electrolytes. Polyelectrolyte behavior was observed for all terpolymers at pH 8.5, as evidenced by high viscosity values at low polymer concentrations and viscosity decrease in the presence of added electrolytes. The reduced viscosity as a function of decreasing pH exhibits a minimum as the terpolymer undergoes a polyanion/polyzwitterion/polycation transition. Comparison of the solution behavior of the terpolymers to terpolymers of 3-(2-acrylamido-2-methylpropane dimethylammonio)-1-propane sulfonate (AMPDAPS), AM, and NaA (AADAPS series) as well as copolymers of AMPDAB and AM (AMPDAB series) have been made. © 1997 John Wiley & Sons, Inc.     

Starch and amylose degradation by 60Co γ-irradiation

The effects of γ-irradiation (0.02–4.0 Mrad absorbed dose and 1.2 Mrad/hr dose rate) on depolymerization and selected physical properties of corn starch and amylose (both dry solid and solution forms) were investigated under conditions used to make graft polymers. Radiation introduces an alkali-sensitive structure, most likely β-alkoxycarbonyl, having a G value of 2.8. A dimethyl sulfoxide (DMSO)-acetic acid-water solvent for intrinsic viscosity was developed that degraded irradiated amylose less than did aqueous 90% DMSO. The G (scission) value of 1.3 for solid amylose irradiated at 0°C under nitrogen is lower than most literature values for either amylose or other polysaccharides. The protection of amylose against irradiation degradation in water by additions of DMSO is noteworthy. The G (scission) for amylose irradiated in 99.8% DMSO is 2.3; whereas, in water it is 30.     

Preparation and Solution Characteristics of a Novel Hydrophobically Associating Terpolymer for Enhanced Oil Recovery

Hydrophobically associating terpolymers were prepared by the micellar copolymerization technique using acrylamide (AM), 2-trimethylammonium ethyl methacrylate chloride (TMAEMC) as a cationic monomer, and small amounts of 5,5,5-triphenyl-1-pentene (TP<0.5 mol-%) as the hydrophobe. The structure of the copolymer was characterized by FT-IR and ¹H-NMR. The aqueous solution properties of the terpolymers were also investigated as functions of polymer concentration, salinity, temperature and shear rate. The results showed that the thickening behavior of these terpolymers are remarkably dependent on both the number and length of hydrophobic segments in the copolymer chains. As expected, the terpolymers exhibited improved viscosity enhancement properties as the concentration exceeded 0.25 g⋅dL⁻¹, due to intermolecular hydrophobic association. Additional evidence for hydrophobic microdomains was obtained utilizing pyrene-probe fluorescence. Additionally, the ternary copolymers showed favorable salt tolerance, temperature resistance, and recoverable viscosity after shearing.     

Solution properties of cellulose triacetate. II. Solubility and viscosity studies

The solubility of cellulose triacetate in a range of solvents was measured, and the results for tetrachloroethane, chloroform, and acetic acid were compared with those from initial phase separation in solvent–nonsolvent mixtures and viscosity–concentration studies. The correlation found between solubilities, precipitation values, and values of the Huggins viscosity constant is discussed with reference to the type of polymer–solvent interaction proposed previously to explain fractionation behavior. A qualitative comparison of solubility–swelling behaviour was also made for a very low molecular weight cellulose triacetate sample in a wide range of solvents. Results are compared with those for higher molecular weight samples and discussed with regard to the cohesiveenergy densities of solvent and polymer. Some attempt has been made to predict suitable solvents for cellulose triacetate, based on consideration of their molecular structures.     

Solution behavior of linear-dendritic rod diblock copolymers in methanol

The solution behavior of spherical dendrimers as well as hybrid-linear dendritic diblock copolymers has been extensively studied, and the size, shape, and ability of these polymers to encapsulate small molecules have led to their comparison with traditional micelles. We have recently reported the synthesis of a new dendritic copolymer architecture, the linear-dendritic rod diblock copolymer, and in this work, we examine the solution behavior of these unique polymers in methanol at 25 degrees C, using dynamic light scattering and intrinsic viscosity measurements. The diblock copolymers consist of a linear poly(ethylene oxide)-poly(ethylene imine) diblock copolymer backbone around which poly(amido amine) branches have been divergently synthesized from the poly(ethylene imine) block. The hydrodynamic radii and the viscometric radii of the polymers were found to increase slowly with increasing generation up to generation 3.5; however, after generation 3.5, the radii were found to increase very rapidly. This increase can be explained by an elongation of the dendritic block into a more rodlike configuration and a corresponding breakdown of the spherical approximation used to calculate the radii. The intrinsic viscosity of the amine and ester terminated polymers was found to follow two very different trends at low generation; however, at higher generations, they followed similar, yet slightly different, curves with the values for the amine terminated polymers only a little larger than those of the ester terminated polymers. At low generations, the chemistry of the end groups and its interaction with the solvent were found to be more important, whereas at higher generations, the highly branched nature of the dendritic block was the more important factor. For the ester terminated polymers, a maximum in the intrinsic viscosity occurred at generation 1.5. Since this maximum occurred at a much lower generation number than is traditionally seen for spherical dendrimers, new scaling relations for the intrinsic viscosity of dendritic rod polymers were developed and were found to support this observation. A minimum in the intrinsic viscosity was also observed at generation 3.5 for the ester terminated polymers and a minimum or leveling off in the intrinsic viscosity at generation 4.0 was found for the amine terminated polymers, which can be attributed to the transitioning of the polymers to a more elongated, rodlike shape and the increased influence of the shape factor on the intrinsic viscosity.