超韧增强剂改性HDPE拉伸一眭能的研究

采用聚乙烯为载体,引入偶联剂处理的CaCO3,弹性体POE,同时加入适量抗氧剂和润滑剂等,制得超韧增强剂,并探讨了超韧增强剂含量对HDPE材料拉伸性能的影响。试验结果表明：随着超韧增强剂含量增加,复合体系拉伸强度呈下降趋势,而拉伸弹性模量则随之上升,当超韧增强剂增加到15％时,断裂伸长率达到最大值,出现脆韧转变。     

改性纳米CaCO3/HDPE复合材料性能的研究

在HDPE中加入高分子偶联剂改性的纳米CaCO3，测试了复合材料的力学性能和流变性能。发现高分子偶联剂的加入改善了无机粒子和聚合物间的结合，促进了无机粒子在体系中的均匀分散，使体系的力学性能上升，高分子偶联剂的最佳使用量（质量分数）是1％；纳米CaCO3的加入减小了体系的弹性，增加了刚性，改善了材料的挤出特性，对体系的流变性能没有产生大的影响。     

乙烯乙烯醇共聚物与聚乙烯共混物的性能研究

以HDPE-g-MAH为相容剂,分别制备EVOH/HDPE二元共混物和EVOH/PA6/HDPE 三元共混物.分别研究EVOH/HDPE和EVOH/PA6/HDPE共混物的阻透性、加工流动性、物理机械性能及其微观形态结构.从SEM可以看出：共混体系呈两相结构,分散相HDPE和PA6以球状均匀的分散在连续相EVOH中.二元体系中,随着HDPE质量分数的增加,共混体系的阻透性能略有下降;加工流动性有所提高;当m（EVOH）∶ m（HDPE）∶ m（DPE-g-MAH）为100∶15∶5时,共混体系的拉伸强度和冲击强度达到最大.与二元体系相比,三元体系的阻透性能和机械性能不如二元体系.     

SBS／EVA改制PP力学性能的研究

研究了PP／EVA、PP／SBS和PP／EVA／SBS共混体系,对其不同配比的共混体系进行了物理机械性能测试与讨论。结果表明,SBS和EVA并用增韧PP时,当质量份大于17份时有着显著的协同效应,PP／EVA／SBS三元共混物具有优良的抗冲击性能。     

光学显微镜在轻质碳酸钙研制中晶体观察的应用

介绍使用光学显微镜观察轻质碳酸钙晶体的方法。此法操作简便、直观,可用于轻质碳酸钙新产品研制和生产中及对轻质碳酸钙的结晶形状、晶体大小和均匀性的观察。     

聚合釜人孔开裂成因分析与修复

解剖聚合釜人孔接管 ,对其裂纹进行分析 ,找出了裂纹启裂的原因 ,提出了人孔修复措施     

CaCO_3粉末作载体固定化脂肪酶催化合成单甘酯

研究了以CaCO3 粉末为载体吸附法固定化脂肪酶的方法。结果表明 ,当酶的用量为CaCO3 质量的 0 3g g-1,吸附时间 1 5h ,所得固定化酶活最高 ,为 15 8 1UCaCO3/g min。研究了固定化酶催化棕榈油固相甘油解反应合成单甘酯工艺条件 ,结果表明 ,固定化酶加入量为 15 0U/g油 ,甘油与棕榈油摩尔比为 4∶1,甘油中水的含量为 4% ,于2 8℃反应 2 4h ,然后将反应体系的温度降至室温 ( 13℃～ 15℃ ) ,9天后单甘酯的含量达 33 4% ,该固定化酶很容易从反应体系中回收 ,重复使用 5次 ,酶活保留 73 37%     

CaCO3改性ABS/PVC/PE-C共混体系的研究

研究了不同种类的CaCO3对ABS/PVC/PE-C共混体系力学性能的影响以及活性CaCO3对ABS/PVC/PE-C共混体系相容性、拉伸强度、弯曲强度、冲击强度、硬度、耐热性能和耐水性能的影响。结果表明：ABS/PVC/PE-C共混体系为部分相容体系,加入活性CaCO3后共混体系的相容性略有提高,在ABS/PVC/PE-C（70/30/10）共混体系中加入活性CaCO3后,体系的弯曲强度和冲击z强度先随CaCO3含量的增大而升高,当CaCO3含量达到一定值后,又随其增大而降低,CaCO3含量在10%-15%时可获得最好的综合力学性能。同时活性CaCO3的加入使ABS/PVC/PE-C共混体系的吸水率有所降低,维卡软化温度和硬度则随着CaCO3含量的增加而有所升高。     

PA1 01 O/CB、PE/CB体系的PTC效应研究

研究了炭黑(CB)含量对LDPE、HDPE、PA1010电阻率的影响,以及LDPE/CB、HDPE/CB、PA101/CB复合体系的电阻-温度特性,发现PA101/CB体系的正温度系数(PTC)转变温度较高,但与HDP/CB体系相比,其PTC强度却很低,不适于制备PTC材料.HDPE/CB体系在160℃附近具有较高的PTC效应,且辐射交联可消除其负温度系数(NTC)效应,容易加工成型,是制备低温区PTC材料的较好体系.     

Toughenability of Nylon-6 with CaCO3 filler particles: new findings and general principles

The mechanical behavior of Nylon-6 blends modified by two types of CaCO₃ particles of 0.7 and 3.5 μm diameter with particle volume fractions ranging from 0.05 to 0.28 was studied between −30 and 60°C in slow tension, and at 20°C in bending impact. Additional experiments were also carried out at 20°C to determine the plane stress fracture toughness of the blends in Single-Edge-Cracked-Plate configurations; all fracture behavior was followed extensively by SEM fractography.

Experiments demonstrated that the particles are attached to the matrix only through a differential thermal–contraction–pressure and particle separation preceded plastic response in all instances. As a consequence of the above ease in debonding, the yield strengths of the blends drop systematically with increasing particle concentration.

In slow tension all blends showed a well defined plastic stretching response following necking, but the stable post-necking stretch was severely limited by an overabundance of large particle clusters which acted as super-critical flaws to initiate premature termination of stretching. The present findings show that in these blends with their high plastic resistances, critical flaw sizes that trigger brittle response are in the range of 8–12 μm, well under the sizes of many of the particle clusters encountered in the blends.

In contrast with the attractively tough response of the rubber modified Nylon-6 blends of Murato lu et al. [Polymer 36 (1995) 921; Polymer 36 (1995) 4771] all present blends showed only disappointing brittle behavior under Izod impact conditions. This was traced to the development of substantial levels of triaxial tensile stresses arising from only partial separation of rigid particles from the matrix in the early phases of impact response.

Based on the new findings a number of general principles on toughenability with both compliant and rigid particle modification are presented and supported by simple micro mechanical models.