口香糖用聚醋酸乙烯酯的合成

采用悬浮聚合法合成口香糖用聚醋酸乙烯酯树脂，研究了ＰＶＡＣ的分子量与分散剂用量，分子量调节剂用量、引发剂用量的关系，测定了不同分子ＰＶＡＣ的玻璃化温度。结果表明，ＰＶＡＣ的分子量是可以调节的。Ｔｇ随着分子量的增大而提高。     

汽车滤纸用聚醋酸乙烯酯乳液的改性研究

介绍了汽车滤纸用浸渍树脂聚醋酸乙烯酯（ＰＶＡｃ）乳液的改性方法。通过乳液聚合的方法,用丙烯酸甲酯（ＭＡ）、甲基丙烯酸甲酯（ＭＭＡ）与醋酸乙烯酯（ＶＡＣ）共聚,旨在改进ＰＶＡｃ的性能。并通过ＰＶＡｃ乳液浸渍汽车滤纸应用试验来评价改性效果。结果表明,用ＭＡ、ＭＭＡ改性ＰＶＡｃ,在一定的工艺条件下,可以进一步提高汽车滤纸的挺度和耐潮性能。     

辅助胶粘剂对涂布性能的影响

本文主要研究了ＣＭＣ（羧甲基纤维素）、Ｓｔａｒｃｈ（淀粉）、ＰＶＡ（聚乙烯醇）、Ａｃｒｙｌ（丙烯酸共聚物）四种辅助胶粘剂对涂料流变性及对涂布纸相关特性的影响，为涂布配方的设计提供参考。     

辅助胶粘剂对涂布性能的影响

本文主要研究了ＣＭＣ（羧甲基纤维素）、Ｓｔａｒｃｈ（淀粉）、ＰＶＡ（聚乙烯醇）、Ａｃｒｙｌ（丙类酸共聚物）四种辅助胶粘剂对涂料流变性及对涂布纸相关特性的影响，为涂布配方的设计提供参考。     

CMA－66浆料的性能及其应用

ＣＭＡ－６６浆料的性能及其应用章学均（上海申新纺织第九厂）ＰｅｒｆｏｒｍａｎｃｅａｎｄＡｐｐｌｉｃａｔｉｏｎｏｆＣＭＡ－６６Ｓｉｚｅ￥ＺｈａｎｇＸｕｅｊｕｎ我厂以生产涤棉产品为主，在上浆中主要使用ＰＶＡ化学浆料。由于ＰＶＡ价格不断提高，用浆成本明显增...     

一种新型食品添加剂—抗坏血酸硬脂酸酯的抗氧化效能研究

以ＰＧ、ＶＥ和ＶＣ作为对照，采用亚油酸通气氧化法对我国自行研制的抗坏血酸硬脂酸酯（Ａｓｃｏｒｂｙｌｓｔｅａｒａｔｅ，ＡＳ）进行了抗氧化效能研究。结果表明ＡＳ的抗氧化作用具有明显的剂量效应关系。当ＡＳ加入浓度达到０．２５％时，对亚油酸氧化的抑制率可达９８．９％按ＩＣ＿５０比较其抗氧化效力依次为ＰＧ＞ＡＳ＞ＶＥ＞ＶＣ。     

PVST3乳液的合成及在造纸增强中的作用

以乙酸乙烯酯（ＶＡＣ）,苯乙烯（ＳＴ）和氯化甲基丙烯酸三甲胺乙酸（ＴＭＣ）为原料,采用元乳化剂乳液聚合法,合成出了一系列ＶＡＣ－ＳＴ－ＴＭＣ阳离子共聚物（ＰＶＳＴ）乳液,测定了乳液的稳定性和转化率,找到了合成ＰＶＳＴ的最优配方和条件。根据电镜观测,此乳液为球形粒子,粒径约为６０￣２００ｎｍ。把ＰＶＳＴ乳液加到竹浆中,测定纸张的耐折度,撕裂强度和环压强度等。当ＰＶＳＴ的用量为０．８０％时,其增强效果     

测定维生素C的提取剂的研究

发现了一种新的Ｖｃ提取剂（２％草酸＋１％盐酸溶液），并与２％Ｈ＿３ＰＯ＿３溶液、２％Ｈ＿２Ｃ＿２Ｏ＿４溶液，１０％三氯乙酸溶液及３％Ｈ＿３ＰＯ＿３＋８％ＨＡＣ溶液作了比较。这种提取剂在Ｖｃ含量测定中将有很好的前景。     

聚乙烯醇对土壤理化性状的影响

针对我国部分烟田土壤理化性状变差的现状，研究了聚乙烯醇（ＰＶＡ）对土壤理化性状的影响。结果表明：①１／１００００～１／１０００ＰＶＡ能有效地形成土壤水稳性团粒（以下简称“成团”）。②ＰＶＡ能明显减少土壤水分散失量。③ＰＶＡ能增加酸性～弱酸性土壤的ｐＨ值。④ＰＶＡ对土壤钾具显著的抗淋溶效果。     

酒精酵母固定化发酵技术的实验与应用

酒精酵母固定化发酵技术的实验与应用刘龙活广东台山市酿酒厂（５２９２００）一、实验室试验１．材料①载体：聚乙烯醇（ＰＶＡ），牌号１７９９；②菌种：ＡＡＤＹ，２１１８９、２１１９０酒精酵母。２．包埋方法①ＰＶＡ液化：按ＰＶＡ：水为１：５～６混合浸透，置８...     

Kalander-Heißkaschieranlagen

The stand of the art for laminating board type materials in calender plants is described. The various procedures, applied in industrial practice, mainly differ in the type of processed glues (PVAc, urea resins) and by the application of these glues on supporting materials (boards) or on films by special preparation. The environmental conditions, the site problems, the materials as well as machinery are reported in detail.     

胶黏剂种类对人造板内结合强度检测结果的影响

使用聚乙酸乙烯酯乳液(PVAc)、单组份聚氨酯(PUR)和热熔胶(EVA)3种胶黏剂粘结金属卡头与试件,检测并分析它们对强化木地板和地板基材用纤维板内结合强度检测结果的影响。结果表明:使用PUR粘结时检测的内结合强度值比使用PVAc、EVA高,其中强化木地板内结合强度高出0.47MPa,地板基材用纤维板内结合强度高出约0.40MPa。     

胶黏剂种类对人造板内结合强度检测结果的影响

使用聚乙酸乙烯酯乳液（PVAc）、单组份聚氨酯（PUR）和热熔胶（EVA）3种胶黏剂粘结金属卡头与试件,检测并分析它们对强化木地板和地板基材用纤维板内结合强度检测结果的影响。结果表明：使用PUR粘结时检测的内结合强度值比使用PVAc、EVA高,其中强化木地板内结合强度高出0.47MPa,地板基材用纤维板内结合强度高出约0.40MPa。     

Hydroxymethylated resorcinol (HMR) priming agent for improved bondability of wax-treated wood

The effects of hydroxymethylated resorcinol (HMR) on the tensile shear strength of wood joints treated with montan ester wax were studied with polyvinyl acetate (PVAc) and melamine formaldehyde (MF) adhesives. Untreated specimens which were bonded with MF and PVAc had similar bond strength properties under dry conditions, but MF bonded specimens’ tensile shear strength values were higher than that of PVAc glued specimens under wet conditions. With both adhesives tested, dry tensile shear strengths of wax-treated specimens were in a comparable range to those of untreated wood, while under wet conditions the strength values of wax-treated specimens were significantly lower than those of the controls. HMR priming increased the shear strength of PVAc bonded specimens under wet conditions and of MF-bonded specimens under dry and wet conditions. The effect on MF-bonded specimens, however, was much more pronounced under wet conditions.     

响应面法优化醇溶性黑木耳多糖-聚醋酸乙烯酯接枝反应工艺

以醇溶性黑木耳多糖为原料,采用过硫酸铵-碳酸氢钠氧化还原引发体系,进行黑木耳多糖(AAP)/聚醋酸乙烯酯(PVAc)乳液接枝聚合反应。在单因素实验的基础上,以接枝温度、单体配比浓度、接枝时间、引发剂添加量为自变量,共聚物接枝率为响应值,采用响应面法研究各自变量的交互作用,确定了黑木耳醇溶性多糖接枝聚合最佳工艺:温度60℃,反应时间2.5h,多糖与PVAc比例为1:3,引发剂量占PVAc质量的4%,在该条件下聚合物接枝率达37.6%。实验结果为高分子天然产物研究提供理论依据。     

新闻纸厂胶粘物组分的分离与分析

对新闻纸厂网前筛筛板上的沉积胶粘物进行了分离与分析.结果表明,以聚醋酸乙烯酯和聚丙烯酸酯为代表的人工合成聚合物以及机械浆中的木材树脂是产生胶粘物的根本来源,但它们在胶粘物沉积中的含量只有约5%.胶粘物沉积中大部是无粘性的碳酸钙和细小纤维,说明碳酸钙等物质会与具有粘性的树脂类物质粘附在一起形成大量的沉积物.     

Tunable synthesis of starch‐poly(vinyl acetate) bioconjugate

Starch‐poly(vinyl acetate) bioconjugate of controllable composition and structure was generated via a combination of RAFT polymerization and copper‐catalyzed alkene‐azide cycloaddition. Firstly, well‐defined alkyne‐terminated poly(vinyl acetate) (AT‐PVAc) was prepared by RAFT polymerization of vinyl acetate in the presence of an alkyne‐containing chain transfer agent. Secondly, azide‐functionalized starch (SN) was synthesized by the nucleophilic substitution reaction of starch tosylate and sodium azide. Then, the bioconjugate was obtained through the click reaction of AT‐PVAc and SN. FTIR, elemental analysis, and NMR were used to verify the structure of the intermediates and the bioconjugate. GPC measurements showed that the MW of AT‐PVAc linearly depended on the monomer conversion and the polydispersity indexes ranged from 1.09 to 1.28. TEM analysis exhibited the final product was able to self‐assemble into micelles in aqueous medium, which suggested the product was amphiphilic and confirmed the successful conjugation of starch and PVAc once more. The content of starch in the bioconjugate could be 47.8–89.2%, which was able to be tailored by the feeding ratio of SN/AT‐PVAc and the MW of AT‐PVAc.     

Effect of adhesive type and glue-line thickness on the fatigue strength of mortise and tenon furniture joints

The fatigue strength of rectangular mortise and tenon rubberwood furniture joints made from polyvinyl-acetate (PVAc) and urea-formaldehyde (UF) adhesives were compared. The results showed that the allowable design stress for PVAc adhesive joints could be set at 30 % of its ultimate bending moment as compared to 25 % for the UF adhesive joint. Further, PVAc adhesive joints have large working tolerances for glue-line thicknesses which make it suitable for mass production furniture manufacturing.     

预分离米糠蛋白类阿片拮抗肽的离子交换工艺

研究离子交换层析法对米糠蛋白酶解物超滤透过液中类阿片拮抗肽的初步分离提取。采用强酸性阳离子交换树脂,上样流速:SV0.8,上样pH值:5.0;洗脱液氨水浓度:1mol/mL,洗脱速度:SV1.2。离体豚鼠回肠(GPI)检定法鉴定表明,在此条件下制备的米糠蛋白类阿片拮抗肽活性得到提高。     

An empirical model for predicting the mechanical properties degradation of bamboo bundle laminated veneer lumber (BLVL) by hygrothermal aging treatment

An empirical 3-D model was developed to evaluate the effect of ambient environment on the mechanical properties and degradation behavior of bamboo-bundle laminated veneer lumber (BLVL) fabricated with different levels of PF/PVAc resin. This model can describe the relationship between the modulus of elasticity (MOE), water absorption ratio, and aging temperature. Five levels of PF/PVAc weight ratio (2:1, 4:1, 6:1, 8:1 and 10:1) and three treatment conditions (18, 63, and 100 °C) were examined in this experiment. Computed tomography (CT) scanning technology was employed to observe the morphology of damage degree as well as explore the mechanism of degradation behavior of BLVL. The results indicated that the 3-D model used for tracking and monitoring the variance of MOE provided good predictors. The higher the water impregnation temperature the larger the water absorption ratio and the higher the MOE degradation were. The aging temperature had a significant effect on the mechanical properties and degradation behavior of BLVL. A linear relationship between modulus of rupture (MOR) degradation and aging temperature was observed. The degradation rate of MOE and MOR increased as the temperature increased. The aging degree tested by CT along with damage of inner board showed the PF/PVAc ratio had a significant influence on the mechanical degradation of treated BLVL when the PF/PVAc ratio was below 6:1. Localized yielding, micro-cracks developing between interfaces, PVAc resin softening along with delamination, and debonding were the main failure models for the BLVL by hygrothermal aging treatment.