薄壁注塑透明聚丙烯专用料的结构与性能分析

对市场上常见的4种薄壁注塑透明聚丙烯专用料的熔融结晶性能、光学性能、分子量分布、力学性能、毛细管流变性能、热收缩性能等进行对比分析。结果表明，K4860H与其他3种透明聚丙烯专用料相比分子量分布最窄；K4860H相对于其他3种透明聚丙烯专用料具有更好的韧性和透明性；相对其他2种透明聚丙烯，K4860H和MT45S具有更高的结晶温度和更快的结晶速率，表明其具有更为优良的结晶能力；4种透明聚丙烯样品的黏度随剪切速率的变化规律相同，表明其具有相同的加工流变性能；K4860H和500B 2个方向的模塑收缩率接近，说明其具有良好的尺寸稳定性；基于以上对比分析可知K4860H主要性能指标优于对比的3种聚丙烯专用料。     

汽车仪表板专用聚丙烯料的研制

作者研究了不同增韧剂，填料，偶联剂，交联剂等助剂对仪表板专用料性能的影响，考查了专用料的结晶行为，微观结构，表观粘度与温度及剪切速度的关系，采用ＡＳＴＭ标准和方法，测试了专用料的机械性能，均已达到国内外同类产品的先进水平。     

高熔体流动速率薄壁注塑聚丙烯专用料的结构与性能分析

采用多种分析测试方法，对3类高熔体流动速率薄壁注塑聚丙烯（PP）专用料的熔融结晶性能、光学性能、分子量分布、力学性能、毛细管流变性能、热收缩性能进行了分析研究。结果表明，K1860与2种市售主流PP1、PP2各项性能相当，其中K1860分子量分布相对PP1、PP2较窄，弯曲性能、拉伸性能更优，可满足大型薄壁注塑制品的生产要求。     

取代芳基杂环磷酸酯类成核剂在薄壁注塑煤基聚丙烯中的应用研究

针对两种取代芳基杂环磷酸酯类成核剂NA21、TD531对薄壁注塑煤基聚丙烯K1860的结晶性能、力学性能以及光学性能的影响进行研究。结果表明:不同浓度成核剂的加入使得结晶峰温度、拉伸强度、弯曲模量较空白样品有了明显提升,尤其是在低质量分数为0.075%时,结晶峰温度分别较空白样品提升5.08%、5.81%,拉伸强度分别较空白样品提升了10.6%、11.5%,弯曲模量分别较空白样品提升了24.2%、21.1%,为薄壁注塑煤基聚丙烯专用料的开发中关于成核剂的优选提供一定的工业参考价值。     

环氧化SBS粘合剂的制备技术

一、产品和技术简介： 本技术是以废饮料瓶片为原料，填加少部分的改性剂．通过专用的反应挤出生产线设备生产出颗粒原料，该料适合于注塑各种高挡塑料注塑部件，综合性能好。     

氯化聚乙烯专用HDPE的结构与性能研究

剖析了三种市场上常见专用料的摩尔质量及其分布、结晶性能、低聚物含量、粒径分布、比表面积、微观结构,提出氯化聚乙烯专用料应该具有中等摩尔质量、窄摩尔质量分布及较好的结晶性能。为保证高的氯化效率,专用料还应具有窄的粒径分布、较低的低聚物含量、较大的比表面积和孔容。同时通过旋转流变仪温度扫描的方式研究了专用料流变性能的温度依赖性。小于220℃时,随温度升高,三种专用料的黏度减小,损耗角增大;在220～230℃之间,三种专用料都发生了一定程度交联,表现为黏度增大,损耗角减小。     

聚乙烯润滑油桶专用料的开发

抚顺乙烯聚乙烯装置通过丁烯—1共聚，调整工艺参数，开发出符合润滑油桶要求的专用料，取代抚顺化塑厂注塑车间润滑油桶塑料原料混合料。工业化产品2810A已经面世。结果表明，在现有装置上只需添加一定量的丁烯—1，便可以提高塑料的韧性、耐环境应力开裂等综合性能，开发生产出了性能优良的专用料，其质量稳定可靠，具有较高的经济价值。     

耐候性PP的研制

以聚烯烃弹性体（POE）为增韧材料、DICPK为结晶成核剂、BsSO4为无机填充剂，研制了耐候改性PP专用料。结果表明，当POE用量为5份、DICPK用量为0．3份、BaSO4用量为30份时，所得专用料能够满足耐候改性PP专用料的性能要求。     

蓄电池槽体专用聚丙烯料的研制

为了替代进口树脂，本所立足国内原料，进行了蓄电池槽体专用聚丙烯料的研制。以洛阳石化总厂聚丙烯ＰＰＦ４０１粒料和粉料为基础，加入增韧改性剂、相容剂、成核剂等进行共混改性，并利用ＤＳＣ考察了专用料间的相容性、成核结晶性，并对力学性能进行了测试。试验结果表明：ＥＰＤＭ与ＰＰ相容性最佳，增韧效果最好；随着橡胶含量的增加，抗冲击性能明显提高，而体系的流动性和拉伸屈服强度变小；ＬＬＤＰＥ加入体系中，与橡胶起到了相互增容的作用，因而体系综合力学性能提高；成核剂的加入使体系结晶速度大大提高，结晶温度有所提高，力学性能也提高；流变分析表明专用料流动性好，可加工范围广。专用料性能达到了技术标准要求，经应用试验得到用户认可     

超支化聚合物改善聚乙烯性能的研究、

将超支化聚合物（HBP）添加到聚乙烯（PE）管道料中，采用SEM、DSC、成型工艺、拉伸实验等手段研究了不同邶P用量对PE结晶性能、注塑工艺、力学性能等的影响。结果表明：HBP的加入可使PE的结晶速率稍有提高，有效改善了PE注塑样条的表面光洁度，提高其熔体流动性，从而改善注塑加工工艺，同时提高了PE的拉伸强度。     

Influencing hardness and wear during the dynamic tempered microinjection molding process by considering isothermal holding time

For semicrystalline thermoplastic parts it is well known that increasing isothermal holding temperature can affect inner component properties, respectively, crystalline structure (e.g., morphology, degree of crystallization, crystal modification, etc.) and, therefore, resulting global component properties such as hardness and wear. Nevertheless, in literature there is no explicit focus on the effect of isothermal holding time during dynamically tempered injection molding process. In this article, semicrystalline microcomponents have been injection molded by varying isothermal holding time within the material's crystallization temperature area. As materials, POM‐C, as a material with relatively high crystallization kinetic, and PA 12, as a material with medium crystallization kinetic, were used. To evaluate the effects on hardness and wear, nanoindentation measurements as well as pin‐on‐disc wear tests were performed. Results show that for fast crystallizing POM‐C an isothermal holding step has no significant influence on inner component and resulting global component properties. For slower crystallizing PA 12, however, the morphology and the degree of crystallization could be influenced and, as a result, hardness could be increased by 21% while wear could be reduced by 30%. POLYM. ENG. SCI., 57:121–128, 2017. © 2016 Society of Plastics Engineers     

Improving mechanical performance of injection molded PLA by controlling crystallinity

Currently, use of poly(lactic acid) (PLA) for injection molded articles is limited for commercial applications because PLA has a slow crystallization rate when compared with many other thermoplastics as well as standard injection molding cycle times. The overall crystallization rate and final crystallinity of PLA were controlled by the addition of physical nucleating agents as well as optimization of injection molding processing conditions. Talc and ethylene bis‐stearamide (EBS) nucleating agents both showed dramatic increases in crystallization rate and final crystalline content as indicated by isothermal and nonisothermal crystallization measurements. Isothermal crystallization half‐times were found to decrease nearly 65‐fold by the addition of only 2% talc. Process changes also had a significant effect on the final crystallinity of molded neat PLA, which was shown to increase from 5 to 42%. The combination of nucleating agents and process optimization not only resulted in an increase in final injection molded crystallinity level, but also allowed for a decreased processing time. An increase of over 30°C in the heat distortion temperature and improved strength and modulus by upwards of 25% were achieved through these material and process changes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

高流动高抗冲聚丙烯的结晶行为与性能研究

通过差示扫描量热法研究了高流动高抗冲聚丙烯专用料K9928的非等温及等温结晶行为,并与国内市场典型牌号K7726H进行了对比分析。结果表明,K9928与K7726H的结晶度非常接近;K9928的起始结晶温度比K7726H高出3~5 ℃,低降温速率下的结晶速率较高,降温速率为50 ℃/min以上时,结晶温度区间较大;K9928内嵌段共聚物含量较多且组成相近,在韧性方面具有优势。     

Primary structure and physical properties of poly(ethylene terephthalate)/poly(ethylene naphthalate) resin blends

The morphology and properties of blends of poly(ethylene naphthalate) (PEN) and poly(ethylene terephthalate) (PET) that were injection molded under various conditions were studied. Under injection molding conditions that make it possible to secure transparency, blends did not show clear crystallinity at blending ratios of more than 20 mol% in spite of the fact that crystallinity can be observed in the range of PEN content up to 30 mol%. Because both transparency and crystallinity could be secured with a PEN 12 mol% blend, this material was used in injection molding experiments with various injection molding cycles. Whitening occurred with a cycle of 20 sec, and transparency was obtained at 30 sec or more. This was attributed to the fact that transesterification between PET and PEN exceeded 5 mol% and phase solubility (compatibility) between the PET and PEN increased when the injection molding time was 30 sec or longer. However, when the transesterification content exceeded 8 mol%, molecularly oriented crystallization did not occur, even under stretching, and consequently, it was not possible to increase the strength of the material by stretching. PET/PEN blend resins are more easily crystallized by stretch heat‐setting than are PET/PEN copolymer resins. It was understood that this is because residual PET, which has not undergone transesterification, contributes to crystallization. However, because transesterification reduces crystallinity, the heat‐set density of blends did not increase as significantly as that of pure PET, even in high temperature heat‐setting. Gas permeability showed the same tendency as density. Namely, pure PET showed a substantial decrease in oxygen transmission after high temperature heat‐setting, but the decrease in gas permeability in the blend material was small at heat‐set temperatures of 140°C and higher.     

TS‐1 molecular sieves filled polydimethylsiloxane membranes for ethanol/water separation via pervaporation

TS‐1 molecular sieves were synthesized and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, and UV–Vis spectroscopy. Results showed that the morphology, crystallinity, and purity of TS‐1 were closely related to the Ti/Si ratio, crystallization time, crystallization temperature, and calcination time. The TS‐1 particles were incorporated into polydimethylsiloxane to form mixed matrix membranes (MMMs), and these MMMs were first used to separate ethanol/water mixtures via pervaporation. The MMMs with 50 wt% TS‐1 (Ti/Si ratio of 0.02) loading showed the highest separation factor of 14.1 for 5 wt% ethanol feed concentration at 50°C. POLYM. ENG. SCI., 56:583–589, 2016. © 2016 Society of Plastics Engineers     

Injection molding of semicrystalline polymers. I. Material characterization

Various material data for an isotactic polypropylene were acquired for the simulation of the injection molding of this material. Viscosity as a function of shear rate and temperature was measured using a capillary rheometer at high shear rates and a cone-and-plate rheometer at low shear rates. Heat-flow properties, characterizing kinetics and induction time of quiescent crystallization, were obtained from DSC measurements. Material data characterizing shear-induced crystallization were obtained from extrusion experiments through a slit die with subsequent quenching of the material in the die after various rest times. The thickness of the shear-induced crystallization layer was measured along with the birefringence in this layer. A model of shear-induced crystallization developed by Janeschitz-Kriegl and co-workers was used to fit the kinetic data. Thus, kinetic parameters such as the limiting shear rate below which no shear-induced crystallization can occur and the characteristic time for the relaxation of birefringence were obtained. © 1995 John Wiley & Sons, Inc.     

A comparison of induction time and crystallization rate for syndiotactic polystyrene

One objective of this study was to measure the crystallization parameters for syndiotactic polystyrene (M_W = 244,000) to support a computer simulation of this material in an injection molding application. A second objective was to introduce a new crystallization rate equation that adequately predicts crystallization rates over a broader temperature range than the Hoffman‐Lauritzen equation. A third objective was to establish a new clearly defined method for determining the true induction time of a semicrystalline polymer as a function of temperature. The new crystallization rate equation introduced in this study has been formulated to give appropriate crystallization rate constants for all the temperatures currently usable with the Hoffman‐Lauritzen equation. In addition, this new equation also predicts appropriate crystallization rate constants outside the range of the Hoffman‐Lauritzen equation from temperatures significantly below the glass transition temperature, T_g, to temperatures significantly above the melting point, T_m. Interestingly, the isolation of the true isothermal induction times from apparent induction times in this study nicely mirrored the isothermal crystallization rates at each specific temperature. Both the true induction time and the crystallization rate curves were found to be similarly unsymmetrical as a function of temperature. Also, the temperature at the minimum induction time and the temperature at the peak crystallization rate determined from nonisothermal crystallization rate measurements were found to be nearly identical. Consequently, the results from this study strongly suggest that there is a significant and potentially very useful relationship between induction time analysis and crystallization rate kinetics.     

Effect of molding conditions on crystallization kinetics and mechanical properties of poly(lactic acid)

Although Poly(lactic acid) (PLA) possesses many desirable properties, above all biodegradability, its heat deflection temperature is too low for many desirable applications. Similarly, to any other polymers, also for PLA the physical and mechanical properties in the solid state depend on the morphology and crystallinity degree, which in their turn are determined by the thermomechanical history experienced during solidification. A large crystallinity degree is highly desirable to increase the heat resistance of PLA but is rather difficult to reach during injection molding due to the very slow crystallization kinetics of this material. In this work, the crystallization kinetics of an injection molded PLA grade was assessed in function of the thermal history by using calorimetric analysis. The cold crystallization kinetics (starting from the amorphous glassy sample) turned out to be faster than melt crystallization kinetics. Following the indications gained from crystallization kinetics, some samples were injection molded imposing different thermal histories. The effect of molding conditions on crystallinity was determined. This finding was adopted to develop a post‐molding stage which allows obtaining crystalline samples in times much shorter (of a factor about two) with respect to samples injection molded in a hot mold kept at temperatures close to the maximum crystallization rate. POLYM. ENG. SCI., 57:306–311, 2017. © 2016 Society of Plastics Engineers     

Influence of processing condition and HA content on the crystallization behavior of HA‐filled EVA biocomposite

Hydroxyapatite/ethylene‐vinyl acetate (HA/EVA) composites with a HA content of 30 and 50 wt% were prepared by injection molding. The crystallization behaviors of EVA under different injection pressure, annealing temperature, and HA content were investigated. Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscope were used to evaluate the composites. The result of FTIR analysis infers the occurrence of hydrogen bonding between HA and EVA. XRD and DSC analyses show that the increasing injection pressure can accelerate the crystallization rate of EVA but it tends to decrease the crystallization degree slightly, which may be caused by the increase of EVA segmental activity and the loss of EVA crystallization order with the increase of pressure. The EVA crystallization degree can be improved by the annealing process. It is found that HA can induce more nucleation sites of EVA, but the crystallization degree of EVA decreases with the increase of HA content. The large content of HA acts to reduce the mobility of EVA crystallizable chain segments and inhibits the crystal growth of EVA. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers