卡德莱多用途固化剂 技术文章

Zhisheng Anton Constantinescu, Adarsh Dalal and Chris Ford

CARDOLITE CORPORATION

500

properties that are characteristic of polyamides (low toxic-

ity, good flexibility, good chemical resistance). Addition-

ally they have outstanding curing properties at low temper-

atures. Because of these characteristics, phenalkamines are

being widely used in marine, industrial maintenance and

civil engineering applications. The results obtained with

phenalkamine resins demonstrate the following properties:

low temperature cure (as low as

and amine derivatives: There is a large variety in

the curing rate and hardness of the resulting resins, when

Table 1: Typical Properties of Phenalkamines I

PHR of epoxy EEW= 190

145180

210

454030

2. Compatibility with the epoxy resins:

The compatibility’s were measured by analyzing the clarity of the cured 8 mil thin film containing epoxy resin and phenalkamine.

Table 2: The Compatibility of Phenalkamines with Epoxies

Systems

NC541 Polyamide Cycloalphatic

Liquid Bis A clear clear

clear hazy

clear Solid

clear

We can see that phenalkamines have very good

20

90

160

230

300

TEMP C (Heating)

0.5

-750

20

90

160

230

300

TEMP C (Heating)

Figure 1.

Cured with

we find

that the phenalkamines’ curing patterns are not affected by the temperature. The curing reaction is almost completed after 24 hours without being affected too much by tempera-ture. The second peak of the curing reaction in (a) and (b)has not been affected by either curing temperature nor cur-ing time. This figure shows that phenalkamine curing agents give temperature insensitive cure. We can use them both during the summer time and winter time without changing the package system. The percentage of cured resin was calculated according to the area of the corres-ponding reaction heat. All the other phenalkamines have similar characteristics and have been analyzed in the same manner. Figure 2 shows the percentage of cure of phenalkamines at a given temperature.

0 12 3 4 5 6 7

8 mil clear

film through

cure at 5°C

12 hrs 18 hrs 24 hrs

*through cure time is obtained by dry time recorder.

4. Physical properties:

All the phenalkamines have the

NX4641

being tested. From the results, we can conclude that the crosslinking density of the cured resin systems does not affect the physical properties considerably. It is highly probable that the

provides

the resins with a high hydrophobicity which reduces the effect of phenolic hydroxyl on the water sensitivity. The following table shows the phenalkamines

NC541

NX4641

Mannich base

Combined with liquid Bis A epoxy

Rgure 3. Water Resistance of Phenalkamines

The results show that the higher the viscosity of the phenalkamines, the better the water resistance.

6. Surface tolerance:

Phenalkamines have a very good adhesion on wet or poorly prepared surfaces, even on water saturated concrete.Because of the high hydrophobic of the side chain the sur-face resin bond is not influenced by the presence of water and thus the obtained adhesion is very good. The results obtained according to the ASTM 4541-89 method are shown in table number 5.

Table 5. Adhesion of Phenalkamine Cured Systems

on Water Saturated Concrete

I

Reference Reference I

System NC541

156

162

81

62

100

Conclusions

The phenalkamines constitute a new class of low temperature curing agents. Their unique chemistry creates a new route of improving a system by chemical modi-fication of its structure. The advantages that result from these chemical changes have important applications in many branches of the industrial maintenance and maritime industries.