Shanghai Daoqin Plastics Co., Ltd.

自 polyethylene (PE) industrial 化以, research polyethylene (PE) material and chemical property 质, 并实施 combined modified measures, is polyolefin industry 一直追求 target/goal. its in has polyethylene (PE) chemical modified more is research hot 点之一. has 关学者针 for different product types polyethylene (PE) and crosslinked additives formed crosslinked system 进行 广泛 in-depth research, versus launch series high property can crosslinked polyethylene (PE) product. 如Dow Corning company separation achieve method and method silicon crosslinked polyethylene (PE). in recent years, inner 刘春林 and other 以DCP（ oxidation 二异丙苯） is agent research LDPE（ low density polyethylene (PE) ） crosslinked. 郭林敏 and other using/adopting oxidation material for high density polyethylene (PE) （HDPE） crosslinked as research 报道.

    has different separation structure polyethylene (PE) between crosslinked research relatively less. is separation various polyethylene (PE) structure and property can advantages, has necessary research different product types polyethylene (PE) 复配时 crosslinked features. research for market upper application most is HDPE and LDPE composite/compounding crosslinked features system research, raw materials ratio, agent concentrated degree and oxidation silicon (SiO2) for crosslinked material micro structure and property can tool has significantly effect/influence.

    一, experiment/testing separation

    1, raw materials

    HDPE, grade 2200J, 齐鲁石化 company; LDPE, grade TN26,齐鲁石化 company; DCP, Shanghai high 桥石化 company; DTBP（ oxidation 二叔丁基）, strong/high company; gas versus method SiO2, grade AEROSIL380, Germany DEGUS-SA company.

    2, experiment/testing device

    SHR-10 type high speed mixed combined machine, 张家港 light machine 械厂; SLF-35B type di screw extrusion machine, formed strong/high polymer/macromolecule engineering company; RC9000 type 哈克转矩流变仪, Germany HAAKE company; RS150 type force viscous elastic 仪, Germany HAAKE company; S530 type electrical 镜, Japan day company; PE-7 type DSC（差示扫描 amount hot 仪）, USA Per-kin-Elmer company.

    3, experiment/testing methods and sample made 备

    (1) HDPE/LDPE composite/compounding crosslinked material made 备

    method made 备: ratio 称取各组 separation, 适当掺 mixed add 入密炼 machine, 于200℃ lower mixing/compounding 10 min. meanwhile can crosslinked system 转矩流变 features.

    extrusion method made 备: separation high speed mixed combined machine separation mixed combined rear, in di screw extrusion machine in mixing/compounding, water ring pellet cutting, temperature degree control scope/range 170-220℃.

    (2) crosslinked material and content 测定

    取一定 amount sample, copper in use 二甲苯 in 索氏抽提 device in 抽提8 h, drying copper in sample, from 而求出凝胶 content.

    (3)  electrical 镜(SEM) analysis

    sample 经二甲苯抽提8h, liquid nitrogen cooling 脆断, surface 喷金, through SEM观测 sample micro 形态.      (4) DSC analysis

    and other temperature melt and crystallization is testing conditions: nitrogen gas gas 氛, sample 2-8 mg,以10.0℃/min rise temperature speed rate rise 至200℃, temperature 5 min消 remove hot history, drop temperature speed rate 10.0℃／min,, non and other temperature crystallization force testing conditions: nitrogen gas gas 氛, sample 2-8 mg,以20.0℃/min rise temperature speed rate rise 至180℃, temperature 5 min消 remove hot history, will sample separation 别以1. 0, 2. 5, 5. 0, 10. 0, 20. 0, 30. 0 ℃ /min from 180 ℃ and other speed drop temperature 至5 0 ℃, again 以10. 0 ℃ /min rise temperature 至180℃.

    二, 结果讨论

    1, crosslinked material content

    table/sheet 1 is crosslinked material raw materials ratio and content. from table/sheet 1 can 看出, LDPE content improve/increase, crosslinked material content has increase. for extrusion pelletizing 说, LDPE increase to 一定程 degree, due to time has 限, for crosslinked material content 几乎没 has effect/influence. in addition, crosslinked process, agent product types is effect/influence crosslinked material content important factors. process time obvious ratio extrusion process long, can obtain more high content crosslinked material.

    2, DCP use amount for HDPE/LDPE crosslinked process effect/influence

    图1显示 DCP use amount for HDPE/LDPE crosslinked system crosslinked process effect/influence. from 图1 can 见, process in 出现2 扭矩峰. 第1 扭矩峰 is add material 峰, resin melt, 扭矩即 decline. rear,DCP引发 polyethylene (PE) crosslinked, system viscosity speed increase large, 出现 第2 扭矩峰. DCP消 consumption full rear, has 3 factors make system decline: mixing/compounding process 继续进行, system 均质化, 逐步消 remove material material local viscosity large phenomenon; reaction hot system temperature degree upper rise, viscosity decline; 密炼 剪切效应, large separation 子断链, system viscosity decline. in time scope/range inner, 扭矩达 to balanced 状态. crosslinked generally in 1. 1-1. 4 min, to balanced 扭矩约 need 6. 0 min. can this category of crosslinked reaction speed rate in temperature degree scope/range inner 变化不 large.

    from 图1 can to phenomenon is DCP concentrated degree increase large, most large and balanced increase large, 反映出 crosslinked material viscosity crosslinked reaction increase more increase trend.
 
 
 
 
 
    3, LDPE use amount for HDPE/LDPE crosslinked process effect/influence

&n    图2考察 HDPE and LDPE ratio/proportion for HDPE/LDPE crosslinked process effect/influence. from 图2 can 看出, add material and crosslinked 峰 出现 time very small, in LDPE use amount scope/range inner crosslinked system melt process 差异不 large, agent separation understanding and crosslinked process 差异也不 large. LDPE use amount 变化引起 crosslinked process main/primary in LDPE content relatively high system its crosslinked value relatively high, is its balanced 扭矩却 relatively low, but also this type of system to balanced use time versus for relatively long. this type of phenomenon understanding is, LDPE large separation upper long content relatively high, in melt and crosslinked 初期, material material temperature degree low, separation 子链缠结严 heavy, 扭矩偏 large. 随 密炼 time long and material material temperature degree rise high, separation 子链缠结 decrease/reduce, system viscosity reduce, decline. high LDPE content crosslinked system balanced versus for relatively low can can is crosslinked LDPE for HDPE increase function 引起.

    4, micro structure SEM

    in HDPE/ LDPE crosslinked process in, selection combined raw materials ratio and crosslinked process can made micro structure versus for 完善 网络 structure, 如图3 示. is, in research process in 发现, in crosslinked system in add 人一定 ratio/proportion SiO2 has absorption agent, has 利于引发 agent dispersion, meanwhile can in resin in formed more more more fine micro 空洞, improvement crosslinked material structure.

    in HDPE/LDPE crosslinked system in add 入2份SiO2 made crosslinked material SEM照 sheet/slice 如图4 示.

    comparison 图3 and 图4 can 见, add 人SiO2 rear, crosslinked material micro structure 确实发生 significantly 变化. in addition, comparison 图4 4 types crosslinked material SEM照 sheet/slice 发现, LDPE use amount for HDPE/LDPE crosslinked material micro structure tool has property effect/influence, is HDPE/LDPE/DCP/SiO2配 ratio is 80/20/0.5/2 crosslinked system crosslinked material structure more is combined 理, density uniform.
 
 
 
 
 
    5, crosslinked material crystallization features

    (1) HDPE/LDPE配 ratio for crystallization features effect/influence

&n    HDPE and LDPE is crystallization features different polymer, composite/compounding crosslinked material DSC熔 melt and crystallization parameters 随LDPE配 ratio 变化而改变 情况见 table/sheet 2, its in TP is melt for temperature degree, Tc is crystallization for temperature degree.

    from table/sheet 2 can 见, LDPE content increase high, crosslinked material Tp呈 decline trend, melt hot significantly reduce, crystallization degree large degree decline. experiment/testing use HDPE melt hot is 223. 6 J/g, LDPE melt hot is 110.5J/g, polyethylene (PE) separation 子链完 full crystallization melt hot is 290. 3 J/g. crosslinked material crystallization degree decline causes 一方面 is crystallization degree relatively low LDPE add 入, 另一方面 is crosslinked material formed retardant crystallization formed. r> 
    table/sheet 2 示 HDPE/LDPE composite/compounding crosslinked material crystallization parameters 受LDPE content effect/influence property relatively 差. 不, overall 看,LDPE content improve/increase, crystallization hot significantly reduce, and 晶体粒 degree large small distribution versus for crystallization AW decrease small. due to LDPE mixed, for HDPE crystallization micro tool has separation function, make crosslinked material 晶体粒 degree distribution 趋于均一化.

    (2) HDPE/LDPE composite/compounding crosslinked material crystallization force 学

&n    is 进一步揭示HDPE/LDPE composite/compounding crosslinked material crystallization 规律, selection AC-5 system research its non and other temperature crystallization force 学. 图5 is AC-5 in different drop temperature speed rate lower non and other temperature crystallization 曲线. from 图5 can 看出, drop temperature speed rate decrease small, crystallization temperature degree toward high temperature direction 偏移. combined generally crystallization property polymer non and other temperature crystallization temperature degree 变化规律.

    deep in certain to crystallization degree lower non and other temperature crystallization force 学方程, 见公式(1).

    its in,D is drop temperature speed degree, t = (T0 -T)/D, T0 is crystallization 开始时 temperature degree, T is t时刻 temperature degree, α is deep method 曲线 斜 rate F(T) in value upper and other mono crystallization time inner system to to crystallization degree need drop temperature speed rate, has material and application 意义. 图6 is lgD and lgt 关系曲线.
 
 
 
 
 
    from 图6 can 见, crystallization degree high, mono crystallization time inner system need drop temperature speed rate value large, for 应F(T) value large.

    三, 结论r>
&n    a)转矩流变实验结果显示, agent concentrated degree and LDPE use amount for HDPE/LDPE composite/compounding crosslinked system crosslinked features tool has significantly effect/influence. from crosslinked 峰出现 time and to balanced time can 看出, crosslinked reaction speed rate in temperature degree scope/range inner 变化不 large.

    b) SEM analysis 结果证实, LDPE use amount and add SiO2 for HDPE/LDPE composite/compounding crosslinked material micro structure tool has significantly effect/influence. obtain versus for micro structure raw materials quality ratio is: HDPE/LDPE/DT-BP/SiO2 is 80/20/0.5/2. r>
    c) DSC analysis 结果显示, LDPE content improve/increase, crosslinked material crystallization and melt hot reduce, crystallization degree decline, crystallization dimensions distribution small.

    d)莫志 deep method can very good 描述HDPE/LDPE composite/compounding crosslinked system crystallization force 学, obtain tool has 指导意义 动 force parameters.