吸湿性聚乙烯的研制

本文介绍用腈纶废丝碱性水解产物、聚丙烯酸铵等高吸水性树脂与聚乙烯共混制备吸水性共混物,并研究了高吸水性树脂用量、粒经、OPE用量、偶联剂的种类和用量等对共混物吸水率和力学性能的影响.结果表明,随着高吸水性树脂用量的增加,吸水率显著增大,但同时,力学性能却明显下降,当高吸水性树脂用量为3%左右时,共混物的拉伸强度和断裂伸长率达到最大;高吸水性树脂的粒径越小,共混物的性能越好;使用偶联剂能较好地改善共混物的加工性能和力学性能,但吸水率降低,耐用性提高;由于加入了适量的高吸水性树脂,共混物还具有良好的抗静电性能,其体积电阻率为10~7Ω·m.     

防水用吸水膨胀橡胶的研制

采用物理共混法制取天然橡胶 /交联聚丙烯酸钠共混物吸水膨胀性橡胶 (WSR)。考察了该共混体系的硫化特性及增容剂、吸水树脂用量、硫磺用量等对WSR吸水性能的影响。结果表明该体系的硫化速度比普通橡胶快 ,加入增容剂可大大提高WSR的吸水速率及最大吸水率 ,且能显著改善试样的外观质量。当天然橡胶 /聚丙烯酸钠质量比为10 0 /10 0时 ,增容体系吸水率最高达到 1832 % (即原质量的 18倍左右 ) ,明显高于未增容体系 ,后者最高吸水率为14 31%     

CPE-g-(AM-co-MAH)增容氯化聚乙烯吸水膨胀弹性体的研究

采用机械共混法将氯化聚乙烯(CPE)与自制吸水树脂丙烯酸钠-丙烯酰胺-甲基丙烯酸羟乙酯三元共聚物P(NaAA-AM-HMA)共混合成吸水膨胀弹性体,讨论了吸水树脂用量、增容剂CPE-g-(AM-co-MAH)用量对吸水膨胀弹性体吸水性能、力学性能的影响。结果表明,未添加增容剂的共混物随吸水树脂量增大,吸水率增大,但是力学性能降低。将增容剂添加到共混试样中,改善了CPE与吸水树脂P(NaAA-AM-HMA)的相容性,提高了体系的力学性能和吸水性能,以加入3Phr的CPE-g-(AM-co-MAH)的增容效果最为明显。     

吸水膨胀型软质聚氯乙烯/羧甲基纤维素共混物的研究

采用扫描电子显微镜等仪器测试并研究了聚氯乙烯(PVC)/羧甲基纤维素(CMC)共混物的结构与性能。结果表明:随着吸水树脂含量的增加,共混物的吸水率和体积膨胀率增大,拉伸强度和断裂伸长率降低;随着水浸泡时间的增加,拉伸强度和断裂伸长率降低;吸水后PVC/CMC共混物中CMC分散相粒径明显增大,与基体树脂界面相互作用下降。     

防水用吸水膨胀橡胶的研制

采用物理共混法制取天然橡胶/交联聚丙烯酸钠共混物吸水膨胀性橡胶（WSR）,考察了该共混体系的硫化特性及增容剂,吸水树脂用量,硫磺用量等对WSR吸水性能的影响。结果表明该体系的硫化速度比普通橡胶快,加入增容剂可大大提高WSR的吸水速度及最大吸水率,且能显著改善试样的外观质量,当天然橡胶/聚丙烯酸钠质量比为100/100时,增容体系吸水率最高达到1832%（即原质量的18倍左右）,明显高于未增容体系,后者最高吸水率为1431%。     

CPE／P（AA-HEMA）吸水膨胀弹性体共混体系的性能研究

采用机械共混将氯化聚乙烯（CPE）、增容剂CPE接枝甲基丙烯酸-β-羟乙（CPE—g—HE—MA）与自制的吸水树脂甲基丙烯酸-甲基丙烯酸-口-羟乙酯共聚N[-P（AA—HEMA）]共混合成了CPE／P（AA—HEMA）／（CPE—g—HEMA）吸水膨胀弹性体。讨论比较了未添加和添加增容剂CPE—g—HEMA2种共混体系的吸水性能（吸水率、吸盐水率和质量损失率）。     

环氧树脂交联腈纶废丝水解物制备高吸水性树脂研究

采用环氧树脂作腈纶废丝水解物交联剂,研究了交联剂用量对产物吸水性能影响,并对吸水树脂吸水性进行测定,制得了吸水率高达920克/克的高吸水性树脂。     

共混型吸水膨胀橡胶的研究

吸水膨胀橡胶(WSR)是一种具有优良吸水性和弹性的特种橡胶,在密封防水等方面有着广泛的应用前景。本文主要研究不同吸水树脂、增容剂与增容剂/吸水树脂比例对NR基共混型吸水膨胀橡胶性能的影响,并进一步考查吸水剂含量对WSR性能的影响。通过正交实验,得出了制备吸水膨胀橡胶的最佳组合;实验表明随吸水剂含量增加,WSR的吸水率增大,力学性能变差。     

CPE／PHP AM共混型吸水膨胀弹性体力学性能

采用机械共混法将吸水树脂（阴离子型聚丙烯酰胺PHPAM）与氯化聚乙烯（CPE）共混制备吸水膨胀弹性体,考察了吸水树脂的粒径,用量及吸水树脂状态对吸水膨胀弹性体的力学性能的影响。研究发现,吸水树脂PHPAM与氯化聚乙烯相容性极差,共混物力学性能能随吸水树脂用量增多而降低,随吸水树脂粒径增大而降低,同时还发现共混物吸水后力学性能有所提高,并在共混前随吸水树脂用量增多而降低,并随吸水树脂粒径增大而降低,同时还发现共混物吸水后力学性能有所提高,在共混前将吸水树脂预润湿有利于提高共混物力学性能。     

遇水膨胀橡胶的研究

考察了用物理共混法制备遇水膨胀橡胶时吸水树脂和生胶等对遇水膨胀橡胶吸水性能和物理性能的影响。结果表明,遇水膨胀橡胶的吸水膨胀率与吸水树脂的种类(物性)相关性大而与其用量(达到一定值后)相关性小;吸水树脂的用量增大,遇水膨胀橡胶的物理性能降低;加入表面处理剂可以改善遇水膨胀橡胶的物理性能;遇水膨胀橡胶的生胶应选用NR,而不宜选用SBR和NBR。     

Physical properties of poly(vinyl chloride)–grafted N‐isopropylacrylamide graft copolymers and corresponding polyblends

The physical properties of poly(vinyl chloride) (PVC) and poly(N‐isopropylacrylamide) [poly(NIPAAm)] blend systems, and their corresponding graft copolymers such as PVC‐g‐NIPAAm, were investigated in this work. The compatible range for PVC–poly(NIPAAm) blend systems is less than 15 wt % poly(NIPAAm). The water absorbencies for the grafted films increase with increase in graft percentage. The water absorbencies for the blend systems increase with increase in poly(NIPAAm) content within the compatible range for the blends, but the absorbencies decrease when the amount of poly(NIPAAm) is more than the compatible range in the blend system. The tensile strengths for the graft copolymers are larger than the corresponding blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 170–178, 2000     

苯乙烯和甲基丙烯酸甲酯梯度共聚物的应用

将用原子转移自由基聚合及连续补加甲基丙烯酸甲酯（MMA）的方法制备的苯乙烯（St）/MMA梯度聚合物P（Pt-t-MMA）作为增容剂应用于聚氯乙烯/苯乙烯-丁二烯-苯乙烯嵌段共聚物（PVC/SBS）和PS/PMMA聚合物合金的增容和改性。扫描电镜结果表明,P（St-t-MMA）可以改善PVC/SBS和PMMA/PS合金的相容性。PVC/SBS合金中加入少量P（St-t-MMA)后,冲击强度从6.0kJ/m^2提高到12.1kJ/m^2,加工流变性能得到了改善。SBS用量也影响PVC/SBS合金的冲击强度。     

Preparation and properties of water‐swellable elastomer

A series of water‐swellable elastomers were prepared by blending chlorinated polyethylene (CPE) with poly(acrylic acid–acrylic amide) [P(AA–AM)]. The effect of component on its water‐absorbent properties such as degree of swelling, swelling ratio, and weight loss ratio was discussed. Mechanical behavior of blends was also investigated. The results indicate that swelling rate of CPE/P(AA–AM) was very quick; the blend reached its equilibrium state in only 30 min. The equilibrium swelling ratio increased with increasing amounts of water‐absorbent resin, the greater the amount of P(AA–AM), the higher the swelling degree. The effect of temperature on swelling ratio was very interesting, below 30°C, with an increase of temperature, the swelling ratio of blend increased, but above 30°C, with an increase of temperature, the swelling ratio decreased, indicating that this is a temperature‐sensitive water‐swellable elastomer. The effect of pH of solutions on the swelling behavior showed that water absorption of blends was heavily influenced by pH. The effect of different metal ions on the swelling behavior were also studied and the results showed that the absorption of blends was decreased dramatically with increasing the charge number of the cation, but was not influenced by radius and valence state of the anion. Owing to the compatibility of the amphiphilic graft copolymer (CPE‐g‐PEG), the equilibrium swelling ratio of the blends increased and the weight loss ratio decreased. Adding CPE‐g‐PEG can improve the mechanical behavior of blends. But too much grafted copolymer can worsen the tensile strength of blends. Tensile strength of blends decreased with an increase in P(AA‐AM). After absorbing water, the material's strength is greater than in the dry state. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1719–1723, 2004     

High water-absorbent and fast-expanding PMMA bone cement with double-bridged structure

The volume shrinkage of polymethyl methacrylate (PMMA) bone cement has been solved by the expandable additives. However, the water absorption and swelling capacity of composite were not maximized as the rapid solidification of the cement and the poor connectivity of the additives in the matrix. In this study, the double-bridged structure was constructed in PMMA-based bone cement. Poly(methyl methacrylate-acrylic acid)-graphene oxide [P(MMA-AA)-GO] was synthesized by the dispersion polymerization, graphene oxide (GO) with sheet layer formed a bridging effect between the poly(methyl methacrylate-acrylic acid) [P(MMA-AA)], accelerating water absorption; hydroxyethyl methacrylate in the liquid formed capillary networks, which bridged all the expansion units, increasing the pathways of water transfer in the matrix. The double-bridged structure in the composite synergistically accelerated water absorption and swelling, causing complete water absorption and swelling performance before solidification, with maximum water absorption and swelling ratios of 125.2 ± 3.2% and 115.2 ± 4.7%, respectively. Surprisingly, the compressive strength of the composite had also been improved, and the maximum value was 78.3 ± 3.2 MPa, which satisfied the minimum compressive strength of acrylic implants in ISO 5833-2002 and ASTM F451-2016. This biomaterial exhibited a promising application prospect as its excellent expansion capacity and mechanical properties.     

PP-HBP改性PP／PVO的流变行为

研究了聚丙烯接枝超支化聚（酰胺酯）（PPHBP）／PP／聚氯乙烯（PVC）共混体系的流变行为。讨论了PP-HBP用煮对PP／PVC共混体系流变行为的影响。结果表明，当PP／PVC共混体系中加入PPHBP不大于5份时，PP／PVC／PPHBP共混体系的表观粘度大于PP／PVc共混体系的；当加入PP—HBP大于5份时，PP／PVC／PP-HBP共混体系的表观粘度小于PP／PVC共混体系的；随着温度升高，PP／PVC和PP／PVC／PP—HBP共混体系表观粘度减小。     

Correlating miscibility of PVC/PMMA blend with polymer chain orientation

Blends of poly (vinyl chloride) (PVC) and poly (methyl methacrylate) (PMMA) with varying concentrations of the polymers were prepared in a film form by standard solution casting method, using methyl ethyl ketone (MEK) as a common solvent. The miscibility of the blend was studied by dynamic mechanical analysis. The chain orientation behaviors of PVC and PMMA in the stretched blend films were studied by infrared dichroism method. Up to 60 wt % PVC concentration in the blend, PVC showed negative values for orientation function whereas PMMA showed independent positive values for its orientation function. On further increasing PVC concentration in the blend, the orientation function of PVC flipped to positive values, and both PVC and PMMA showed same magnitude and trend in orientation behavior. The chain orientation behavior of individual polymers in the immiscible compositions of the blend was observed to be independent, while there was a high degree of cooperation for chain orientation in the miscible composition. Change in the miscibility of the blend was simultaneously accompanied by conformational changes in PVC. The change in orientation behavior is interpreted in terms of curling of polymer chains in the immiscible phase. The polymer chain curling hypothesis used here is applicable independent of the type of polymers in the blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 624–630, 2006     

Small‐angle X‐ray scattering study of modified porous suspension–poly(vinyl chloride) particles

Small‐angle X‐ray scattering (SAXS) was applied to investigate the microstructure of unmodified and modified porous commercial suspension‐type poly(vinyl chloride) (PVC) particles. The modified PVC particles were prepared by an in situ stabilizer‐free polymerization/crosslinking of particles absorbed with a monomer/crosslinker/peroxide solution. The modifying polymers include styrene with or without divinyl benzene (DVB) as a crosslinker and methyl methacrylate (MMA) with or without ethylene glycol dimethacrylate (EGDMA) as a crosslinker. The SAXS method was used to highlight the effect of polystyrene (PS) on the microstructure of PVC particles and to evaluate the characteristic lengths, both in the PVC/PS and the PVC/XPS (PS crosslinked with 0 and 5% DVB, respectively) systems. A model is suggested, where during the synthesis modification process, swelling of PVC by styrene and styrene polymerization occur simultaneously. PVC swelling by styrene causes destruction of the PVC subprimary particles, whereas styrene polymerization leads to phase separation resulting from incompatibility of the polymers. It was further suggested that because of PVC swelling by styrene, structure of the subprimary particles is lost. Therefore the characteristic lengths of PVC/PS and PVC/XPS, as calculated from the SAXS measurements, were attributed to the size of the phase‐separated PS and XPS inclusions, respectively. The SAXS method also shows that PMMA and XPMMA do not influence the PVC microstructure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1024–1031, 2005     

Fracture and impact strength of poly(vinyl chloride)/methyl methacrylate/butadiene/styrene polymer blends

The Izod impact strength of poly(vinyl chloride)/methyl methacrylate/butadiene/styrene(PVC/MBS)polymer blends can be changed significantly with different levels of MBS and/or MBS particle size. The following results were obtained by investigating the fracture of PVC/MBS test specimens: (1) The dependence of the Izod impact strength of PVC/MBS blend on MBS particle size confirms a maximum around a MBS particle size of 2000 Å. When MBS particle size is smaller than 2000 Å, the Izod impact strength increases with MBS particle size, and crazing occurs mainly in this region. When MBS particle size is larger than 2000 Å, then the Izod impact strength, in contrast, decreases with increasing MBS particle size, and both crazing and shear yielding occur, mainly in this region. (2) Tensile experiments of PVC/MBS blends carried out under various conditions showed that the amount of energy absorption increases with decreasing MBS inter-particle distance and with increasing MBS particle size when crazing is the main energy absorbing mode. The MBS inter-particle distance dominates the energy absorption when shear yielding is the main energy absorbing mode. (3) Therefore, the Izod impact strength of PVC/MBS blends and the maximum around a MBS particle size of 2000 Å can be explained as follows: Below 2000 Å, the energy absorption by crazing dominates the total energy absorption, and the energy absorption by crazing increases with MBS particle size. Above 2000 Å, the energy absorption by shear yielding is dominant, and the energy absorption by shear yielding increases with decreasing inter-particle distance, that is to say, decreasing MBS particle size.     

丁腈橡胶/聚氯乙烯/受阻酚AO-60共混物的结构与性能

用差示扫描量热法、X射线衍射法、扫描电子显微镜及元素分析法分析了丁腈橡胶(NBR)/聚氯乙烯(PVC)/四[β-(3,5-二叔丁基-4-羟基苯基)丙酸]季戊四醇酯(AO-60)共混物的结构,并研究了共混物的阻尼性能及力学性能。结果表明,当AO-60用量小于50份时,其分子在基体中以非晶态形式存在;当AO-60用量超过50份时,过量的AO-60形成聚集体并在基体中形成少量的晶体;NBR/PVC/AO-60共混物内部呈现“海相-岛相”结构,连续相主要是NBR,而分散相主要是PVC与AO-60分子。NBR/PVC/AO-60共混物的损耗因子-温度曲线呈双峰特征,且随着AO-60用量的增加,峰值明显增大。当AO-60用量为50份时,NBR/PVC/AO-60共混物的综合力学性能较佳。     

ABS/PVC共混复合材料耐老化性能研究

在ABS／PVC基础配方中通过添加紫外线吸收剂、抗氧剂等助剂，研制了耐老化ABS／PVC共混塑料，并研究了不同品种的紫外线吸收剂和抗氧剂对提高ABS／PVC共混复合材料耐老化性能的影响。结果表明，紫外线吸收剂UV-327和抗氧剂1076能有效提高ABS／PVC共混塑料的耐老化性能。